Throw it in N?
Posted by SparkeeMalarkee@reddit | askcarguys | View on Reddit | 208 comments
Why is it that when I ask the question to people knowledgeable about cars: “Is it bad to throw an automatic car in neutral at every red light, or just every long red light?” , I get 100 different answers which either conflict, or agree with each other, but cite different reasons for doing so? Is there one concise good answer to this?
ads1031@reddit
I'd like to respond to your question with a question of my own. Why would it be desirable to shift to N at all?
In a manual, shifting to neutral is obvious. It prolongs the life of the throwout bearing and you get to rest your left leg. But in an automatic? The torque converter just sits in its stall state and the engine idles along. Where's the advantage over leaving it in D?
SparkeeMalarkee@reddit (OP)
I find that my engine idle smoother because it’s not laboring against the torque converter at idle, and I can take my foot off the break on a level patch of ground
enilcReddit@reddit
This sounds like a “get a louder radio” type of fix to your engine problem.
ads1031@reddit
I used to have a car that would idle rough in D and smoothly in N: a 2011 Cadillac STS. Eventually, I discovered that the car was idling roughly because the motor mounts were worn out. The left-side mount had even torn completely. Replacing the motor mounts eliminated the rough idle entirely. With fresh mounts, you could barely tell the engine was running in any gear, D or otherwise.
I would assert that any modern car that idles roughly in D has some variety of problem.
I would also assert that taking your foot off the brake when idling, wether on level ground or otherwise, is an unsafe practice. You're surrendering control of your vehicle to the environment in which it resides. I'll admit that I'm guilty of doing the same thing in my Miata, which has a 5MT, but when I do so, I always pull the parking brake so that the vehicle is still held in place, even on level ground.
SchoolSea3900@reddit
Which STS did you have? My second car was a 06 Northstar v8 STS with every single option. It was such a nice car. Quick and feature packed where it mattered. Heads up display, one of the first cars with magride, LSD, block heater, transmission cooler, automatic radar system for proximity warning and auto cruise control, ZF steering rack and so much more. That car was absolutely loaded and handled so well for 4k lb boat.
ads1031@reddit
I had a 2011 with the v6. I only had the passive suspension, but it still handled so well.
Honest_Road17@reddit
So you like to turn your brake lights off when you are in traffic. Seems like a plan.
Lavaine170@reddit
OP is literally too lazy to keep their foot on the brake pedal
u3b3rg33k@reddit
this is why i drive manual. i HATE having to hold the car back with the brake!
Lavaine170@reddit
Literally the funniest thing I'll read today. Stop skipping leg day at the gym and it will get easier.
Downtown_Reward_6339@reddit
Literally how it was designed to work.
pizzaanarchy@reddit
Literally what it was designed for.
Feisty-Journalist497@reddit
the design is very human
WaterDigDog@reddit
To err is human
August_72_West@reddit
Checkmate
Late-Button-6559@reddit
Less stress on the engine. Less stress on the trans. Less fuel use. Less stress on driveline.
Almost all automatics aren’t ‘idling’ in drive. They’re slightly fighting against rue flywheel.
Take your foot off the brake and see what happens for yourself.
If you have a car that shows instant fuel use in litres/gallons per hour (when stationary), pay attention to the fuel use in D vs N.
Pay attention to rpm. Pay attention to nvh in the cabin.
Pale-Ad6216@reddit
My wife had an automatic Miata for a while. Super sporty and fun car to drive , but holding the brake at a red light with the car in D caused some vibration that I found to be somewhat annoying. Checked motor and transmission mounts. Nothing mechanically wrong. If I put it in N while waiting at lights, it would idle away smooth as silk. OP did mention in his post that it can mitigate vibration which it absolutely did for me and made perfect sense to do so. My wife hated the vibration, but for her she didn’t feel shifting at lights was worth the effort.
RemoteVersion838@reddit
In anything built in the past 2 decades, this is the main reason to do it.
the_Q_spice@reddit
The only possible benefit would be for DSGs or DCTs.
But most manufacturers are pretty smart and have a clutch disengagement programmed in for this exact case.
VAG's DSG cars do this for example. So while your gear lever doesn't have N selected, you are still in neutral when stopped (with the benefit of 1st being pre-selected and that gear cluster being pre-loaded to be engaged as soon as you release the brake pedal).
DSGs are obviously a special case, but are pretty awesome for this exact reason (as well as being fast AF to shift).
kefirr@reddit
Wrong, DSG keeps the clutch at bite point when stopped in D and fully disengaged in N, you can feel it and hear it. And you can see it in VCDS
StarHammer_01@reddit
At least on my old ass toya matrix. Shifting to N reduces engine rpm to 600 and dosnt make the car shake.
Solid-Tumbleweed-981@reddit
I wonder if that works for new Subarus lol. My friend has a Crosstrek and it makes me so car sick lol. It's newer and like sitting at a light I was like wtf is wrong w this thing. I test drove one and was like nope these things really do just suck that much
Honest_Road17@reddit
Change your motor mounts.
koyaani@reddit
Read the post
Honest_Road17@reddit
I did. If the engine is flopping around with the car in drive, the motor mounts are most likely trashed. Even on "old ass" Toyotas they are wear items.
koyaani@reddit
If you read the post, then what is the point of supplying any of that info even if accurate?
Honest_Road17@reddit
Did you see who I was replying to?
Go away weirdo.
AdEastern9303@reddit
That is a specific case and there is a specific advantage (to you) for doing this. In my car, I need to press firmly on the brake and sometimes, I just don’t feel like it if it is a particularly long wait like in a drive through. For regular lights, I would never go to N.
o0Spoonman0o@reddit
Sure and his use case is "my transmission am broke" (or more likely, the torque converter)
KneeBasher420@reddit
I drive a rattly old diesel, so at idle in D it resonates enough that it messes with my music lol. I usually don't bother but it's nice when I do.
that_dutch_dude@reddit
because as long as its in gear the torque converter is giving quite a bit of resistance as it wants to keep pulling the car foward.
BagRight1007@reddit
Right, but what does it do? Does it help in any way?
Akward_Object@reddit
Engine works less hard, you save fuel.
xangkory@reddit
It is at idle. Idle is idle, doesn't matter if it is drive or in neutral, same RPMs and uses the same amount of gas.
Altruistic_Fan_5122@reddit
It's is not. Idle is not idle. Idle under load will burn more fuel even at the same rpm.
My diesel starts to build boost at idle in drive but drops to actual 0psi in neutral or park.
Akward_Object@reddit
When I had an auto, putting it in N would drop the RPMS. Not surprising as the engine does not have to overcome as much drag in the transmission. Might not be true for all types of automatic transmission though. And after comparing not using N when waiting at a red light or not, there was noticable fuel savings too.
politicsBgone@reddit
You push less on the brake pedal.
morningstar243@reddit
This 💯
Friendly-Inspector71@reddit
Fuel consumption if the car doesn't have start-stop.
Because it takes more power to idle the engine against a stalled torque converter. It also reduces the heat load on the transmission, but it's not that big of a difference.
beaushaw@reddit
You could probably save more fuel by taking a shit before you drive your car. Lighter is more efficient.
The entire discussion is dumb.
EnlightenedCorncob@reddit
Going potty before a trip is just good advice.
bcsublime@reddit
Visiting tinkle town is a must before a trip
Disastrous-Group3390@reddit
A 2005 GTO with a 400hp 6.0 burns one gallon per hour at idle (manual trans, out of gear.) If the difference for an in gear auto were 2%, we’d ve talking less than three ounces per hour. (Stop Start isn’t much if a savings either, ESPECIALLY balanced against the wear and tear.)
Friendly-Inspector71@reddit
Modern Start-stop systems work well and barely add any wear.
I was just providing a reason someone might have for switching to neutral.
The other reason might be because the slow creeping isn't desired.
ads1031@reddit
But the converter and a portion of the transmission are still mechanically coupled to the engine. The engine is still spinning them. After all, an automatic transmission's pump is still running, so long as the engine is.
I used to have a car with auto stop. Auto stop would only stop the engine if it was left in D. Shifting to N, and by extension, R or P would immediately restart the engine.
Friendly-Inspector71@reddit
Right, that's why I said
angrycanadianguy@reddit
… fuel consumption? How so?
Friendly-Inspector71@reddit
Did you read the paragraph below?
BobDerBongmeister420@reddit
A few % increase of an already very low number is irrelevant
Friendly-Inspector71@reddit
I'm not saying it's a lot lot. I was just answering the question of the TC.
worromoTenoG@reddit
Leaving it in D while stopped puts a non-trivial load on the engine, increasing idle fuel consumption.
KillrBeeKilld@reddit
I would say it is a very trivial load on the engine.
SkiyeBlueFox@reddit
Incredibly trivial. Notice how when you go from n to d your revs are the exact same even though the tc is technically drawing some energy
GeriatricSquid@reddit
Same with the air conditioning but both are modern marvels of computer controlled engines.
Dzov@reddit
Putting it in N every stop puts more wear and tear on those controls, linkages, and transmission parts. Whether it matters or not, who knows?
oboshoe@reddit
Some years ago I went through this same calculation and in the end, I decided that the extra wear and tear on the linkages was more than the extra wear on rest of the transmission.
Especially since the turbine and half the transmission is still engaged in N anyway.
So I just keep my foot on the brake unless the stop turns out to be really really long then I might shift to N just to relax a little.
Ahaayoub@reddit
When you leave it in D, the engine's power is turning the torque converter, but you are pressing the brakes, so the power is converted to heat.
Lucky_Total_278@reddit
Are you driving a four banger with a miss in one cylinder? That will screw up your idle
DryFoundation2323@reddit
It's not going to hurt the transmission but I don't see what it's going to help either. Mechanical engineer here.
Cpolo88@reddit
Sounds like y'all drove some pos cars that needed to be put in Neutral. That's fine. I haven't bought an automatic car in years and when I did, my 2018 zf tranny does fine. No need to put in N. But you do you Op
TutorNo8896@reddit
The awnser is NO, its fine. You cant hurt it unless you forget and rev real high and drop it into D. I put my POS into N or P at a long wait because if the AC is on it vibrates a little. I work as a mechanic and have absolutely no interest into fixing whatever is going on. A word about the brakes though... gotta keep on em a little, because when you get rearended even just a little it takes some time for your brain to figgure out what happenend, and what is currently happening is you are rolling into cross traffic.
Eskimo_Brothers17@reddit
What's the point of doing so? It doesn't save gas and it leaves you vulnerable, delaying your "escape" if need to suddenly move to avoid being rear-ended .
Friendly-Inspector71@reddit
Why wouldn't it save gas to disconnect the torque converter?
Maybe the difference is just a couple of percent but there has to be a difference.
Modern cars with start-stop are way more effective at saving fuel though.
oboshoe@reddit
Because the amount of gas sent is determined by the cars CPU.
It's not like the carb days where the gas draw is a result of load.
If the car is sending more fuel at idle, that would be a conscious decision by the maker to burn more fuel at idle - which literally costs them millions extra in CAFE fees when calculated across the fleet.
So the amount sent is the same at idle regardless of N or D, and the loss of a few rotations per minute due to increased friction on the turbine is acceptable.
Friendly-Inspector71@reddit
That doesn't make any sense.
The Air-fuel ratio determines the amount of fuel consumed. A carbon and an ECU try to keep it at an optimal ratio.
The ECU has control over the throttle which a carb doesn't, so it can adjust the idle to account for load conditions. The torque converter is a load that the ECU might slightly open the throttle for to keep the RPMs steady, so it has to inject slightly more fuel to compensate.
oboshoe@reddit
what i've noticed is that at idle, between N and D it doesn't both to keep rpms the same. the small extra load induced by still turbine costs a few RPMs, but the cpu doesn't bother to correct it.
it could of course, but in the carabiner driven it doesn't.
Hoovie_Doovie@reddit
If the ECU did nothing but let the RPMs drop, they'd fall below the point where the engine can keep running, and stall. You can see this in carbeurated engines with the idle set too low. If the car is put into gear the engine will stall.
The ECU compensates for the extra load of a transmission in D by increasing idle air control, therefore letting more air into the engine. When there is more air, there needs to be more fuel. Fuel consumption goes up with the transmission in D. Fact.
oboshoe@reddit
Right, But there is a tolerance band.
If the ECU has a tolerance band of letting it drop 50rpm due to turbine load in D vs N, then you would see just a minor drop without added fuel.
I'm not saying that it doesn't go up in D at idle. IM just saying that in the Fords and GMs that I've tested this with, I've not seen a difference.
Hoovie_Doovie@reddit
What I'm trying to tell you, is that the rpm drop you're seeing is WITH the ecu compensating. If the ecu wasn't compensating, the rpm would drop to the point the engine is chugging (not a good driving experience) or stalling (dangerous).
Friendly-Inspector71@reddit
I've only driven one automatic with a torque converter. That one was slightly struggling at idle but was also not treated well.
The torque converter lockup is something I paid more attention to.
The more common DSG around here will just open a clutch once stopped with applied brake.
Cynyr36@reddit
Because generally the idle just drops a bit with the transmission in gear rather than adding more fuel.
Pimp_Daddy_Patty@reddit
It's not about idle speed. It's about load. Every ecu needs to compensate for being in gear vs neutral.
Friendly-Inspector71@reddit
The idle drops because there is a bigger load on the engine. The car compensates a little but not fully.
The last automatic cars I got to drive with an instant fuel gauge were all DCTs. They just open the clutch when the brake is applied, so effectively shift into neutral.
Cynyr36@reddit
Right, but that doesn't necessarily mean the ecu adds more fuel. It can just let the revs fall. You'd really need to hook up a real scan tool and ask the ecu how much fuel it wants between the two arrangements. It probably makes just about 0 difference unless you plan on idling for a significant portion of your total run hours.
Friendly-Inspector71@reddit
I don't have access to an automatic with a torque converter currently. The last one I got to drive was crashed over a year ago.
I only have access to DSGs and they also have start-stop. Or manuals.
DarthSwash@reddit
It might save fuel, but Its likely so miniscule to be negligible. I also detest auto stop/start systems in vehicles and am in a constant state of war agianst them. Happy to report my newest vehicle purchase doesn't have this nonsense.
Friendly-Inspector71@reddit
I'm unhappy to be a pedestrian in a city full of cars idling at red lights. But luckily there are more electric cars, so the air gets better even if some petrol heads like to hear their engine at the lights.
SparkeeMalarkee@reddit (OP)
I find that the engine idle smoother and I can take my foot off the break because it’s not laboring against the torque converter
whyugettingthat@reddit
There are many many reasons you should not do this. First is safety, always be in gear so that in the event of an emergency your car is already ready to move.
Second is that engines are designed to be under load , idling against the torque converter is first gear (unlocked torque converter therefore slips) provides cushion (load) , where as idling in neutral is harder on internals.
Third is that idling against your unlocked torque converter causes no wear BUT adding thousands of neutral to drive shift cycles to your transmissions lifespan will eventually cause premature wear/failure.
Keep it in drive.
Hoovie_Doovie@reddit
Laughs in 6MT
william_f_murray@reddit
You should never ever ever leave your car in neutral with your foot off the brake on the road. If you can't manage to keep your foot on the brake at a stop light, work out or get a car that has brake hold. You're endangering yourself and others doing what you're doing.
True_Goat_7810@reddit
Why?
Why do I need a foot on the brake if the road is flat enough to not roll away? I cant see the endagerment.
Sandstorm135@reddit
Sitting in the middle of the road without your brake lights on probably isn’t a good idea
True_Goat_7810@reddit
uhm. Why would that be?
Please dont tell me someone would rear end me without a brake light? If its daylight, you can clearly see the car. If its dark, my taillights are on. You wouldnt drive into a parked car, would you?
CartierWlayvo@reddit
Quick glance up from phone- sees no brake lights, assumes your rolling
Looks down to phone again… and boom rear-ended
True_Goat_7810@reddit
its probably good i live somewhere where people actually look at the road, not their phone lol.
itsjakerobb@reddit
Brake
SparkeeMalarkee@reddit (OP)
Talk to text don’t care
Yummydain@reddit
99% of people I see on the road have their face planted in their phones at red lights. They’re not worried about “escaping” anything.
KeanuIsACat@reddit
As a motorcyclist that likes to spy in everyone's cars at stops, this is so true. Everyone in looking at their phones, in every occupied seat.
Gahreesen@reddit
While that's true, it doesn't make posters statement less true. So to be clear IF you are the type who doesn't have your face in your phone, or any other reason you are not paying attention, it's to your advantage to be able to move quickly should the need arise. Happened to my wife last year. Guy in pickup slams on brakes, hits car behind, shoves car into the space my wife was in because she was able to move forward 5 feet and avoid.
Special-Reindeer-178@reddit
Please hit me. Hard. Straight up the ass. Please. Begging.
Mommy needs a new car.
Even if I could "escape" an incoming rear-end collision, I aint gonna
Potential4752@reddit
If there is a car in front of you and a car behind the you are not escaping anything.
Fat_Bearded_Tax_Man@reddit
Youre not moving fast enough from a stopped position to avoid a collision.
Eskimo_Brothers17@reddit
I disagree. Keeping a eye on the rearview at a red light and ready to move has definitely prevented me from being rear ended. Even one time is worth it to me! YMMV
matt71vh@reddit
Every motorcyclist does this for life preservation.
Potential4752@reddit
Motorcyclists have room to maneuver.
ButchDeanCA@reddit
I agree. I even leave enough space if there is a car infront of me and preferably a clear lane to the side if available to swiftly turn into should I need to.
Call_me_Tom@reddit
At the other end of that, years ago I was stopped at a light at the end of a freeway off ramp. When I looked in my rear view mirror I saw a truck approaching me and not slowing down. I had the car in neutral and took my foot off the brake and when the truck hit me it softened the blow.
quik916@reddit
If you had it in gear you could have mashed the gas and really softened the blow.
koyaani@reddit
Depends on the timing. Jamming down the accelerator will cause the rear end to dip down, potentially leading to a collision with more downward force applied from the truck to the car
william_f_murray@reddit
Or, hear me out, you'll be moving so you can get out of the way or only get hit at 50 instead of 70.
koyaani@reddit
Depends on the circumstances
william_f_murray@reddit
It absolutely does not. Being a sitting duck is NEVER the best option.
koyaani@reddit
Sometimes it is
william_f_murray@reddit
Give me an example of one single instance where being hit while sitting still is better than being hit while trying to move out of the day.
koyaani@reddit
They're waiting for a passing train in front of them
quik916@reddit
The impact speed reduction will almost surely be safer than just sitting there static, and taking the hit like a wall.
that_dutch_dude@reddit
it actually does save gas because the engine doesnt have to work against the torque converter.
Pimp_Daddy_Patty@reddit
Whovever downvoted you is a moron. Idling against a torque converter puts more load on the engine which will absolutely burn more fuel. Whether or not its a noticeable difference will depend on the vehicle.
o0Spoonman0o@reddit
It would depend on if you're talking about vehicles after or before 1990ish (Carbureted + hydraulic automatics). Big V8's with carbs and no electronic idle control.
Outside of this you're not gonna see a difference. Modern automatics are not sucking up a bunch of extra fuel at idle.
Pimp_Daddy_Patty@reddit
No one said anything about "a bunch of additional fuel". It may be small, but additional load is additional load.
H0SS_AGAINST@reddit
To be fair it does save a little bit of gas.
You're no more vulnerable than someone in a manual transmission. You must have some finely tuned Spidey senses to escape a read end collision.
oboshoe@reddit
I've measured it in my cars with ODB II data and I have never seen any difference in fuel consumption between N and D at idle.
But it's certainly possible that some manufacturers send more fuel. I just haven't driven one that does.
Pimp_Daddy_Patty@reddit
Did you measure engine load and injector pulse width?
Tundra_Dragon@reddit
My Powerstroke Diesel tells me the ml/stroke, as well as GPH, and if there's any difference in fuel consumption, it is so negligible as to be stupid.
Shifting to neutral on an auto trans could chuck you in reverse, which if you're still rolling is terrible for every part of your driveline. If someone's behind you, and your reverse lights turn on, they could take it as a sign of agression, not to mention you could dumbass yourself into their car in reverse.
H0SS_AGAINST@reddit
Interesting. I have not done that, just thinking through the mechanics of it, when in D the turbine is locked thus is proving more pumping resistance to the impeller. When in N the turbine is freewheeling. Sitting in D does elevate the trans fluid temp, that energy can only come from fuel consumption. I would anticipate the difference is negligible so it may be that the OBD reader just doesn't have the precision to indicate the difference.
GraphicWombat@reddit
Idk about being able to “escape” from an accident. I would be curious to know if the pre collision safety measures would be active and work in neutral??
SevroAuShitTalker@reddit
You see a car coming up fast from behind - you have a better chance to try and avoid in in drive already.
Motorcycle people tend to treat it as a sin to not be in gear at lights for that reason
Gwendolyn-NB@reddit
The information here us hilarious... shifting to neutral doesn't disconnect the torque converter nor the pump... its not like a clutch in a manual car.
It just changes the fluid path the pump is pumping the fluid in the transmission; its still pumping fluid.
Hoovie_Doovie@reddit
Shifting to neutral does disconnect the driven wheels from the engine though. Very similar to a manual transmission.
In D, the engine is constantly trying to drive the wheels, in N, there is no load on the engine.
Talentless_Cooking@reddit
Switching from d to n can and likly will result in premature linkage wear. If you like doing stuff all the time, just get a manual car.
SparkeeMalarkee@reddit (OP)
Can’t get a manual full size work van
SirWillae@reddit
Without performing repeatable, controlled experiments, I wouldn't even hazard a guess. But as to why you get different answers with very strong opinions...
There's a lot of mythology surrounding cars. People draw conclusions from anecdotes that they observed once or twice without any real data to back it up. Honestly, that's human nature. It's what kept our ancestors alive, so it's kind of built into our DNA.
SparkeeMalarkee@reddit (OP)
This comment section is no exception
eoan_an@reddit
Why would you do that?
Apply the "lazy" approach: do the minimum. Going to N is work. Just stay in gear.
Likewise for a manual, holding the clutch is work, go in neutral.
So easy
aspire1690@reddit
Okay here’s the facts:
N is ONLY for pushing the car or towing IF the engine is running
Don’t put it in N on a traffic light
Don’t have it idling in N for a longer period of time
Don’t tow it in N with engine off
Don’t shift the PRNDL if not necessary
While in N the transmission doesn’t get lubricated enough since automatic transmissions need the engine powered oil pump to run as intended. If the wheels spin the transmission (towing for example) and the pump doesn’t produce enough oil pressure (engine off) the transmission can take damage.
This only applies to automatics though, manual is fine in N
No_Base4946@reddit
> While in N the transmission doesn’t get lubricated enough since automatic transmissions need the engine powered oil pump to run as intended
So the pump isn't running at all if the gearbox is in neutral?
aspire1690@reddit
I didn’t make myself clear, wrote the comment to hastily. It’s fixed now, hope it makes more sense. Ask away if something is still unclear
No_Base4946@reddit
Heh, it was a Socratic question. Lots of people in this thread saying that the pump doesn't rotate when the gearbox is in neutral, but if that was the case how does it get hydraulic pressure to select a gear when you move it out of neutral?
I suspect a lot of people have never removed and refitted a torque converter and it shows :-D
gt500rr@reddit
I don't drive auto anymore but with old school torque converter types I'd shift it to neutral (3 speed XF Falcon van) just to reduce the brake pressure required to hold it. Unless the carb was heat soaked then I'd keep it drive. These days all my cars are stick shift so to be nice to the throwout bearing I leave it in neutral. Honestly I'd just leave it in drive and not worry about it.
kikiacab@reddit
No reason to put it in neutral, you’re putting yourself at a disadvantage for no benefit.
Honeydew-plant@reddit
The main problem here is safety for if you need to avoid an accident and for insurance reasons if you do get in an accident, but it will do no other harm if you want to take the risk.
RemoteVersion838@reddit
Like a lot of automotive lore, it has roots in legacy technology. Older automatics used to put more of a load on the engine at a stop so there was a noticeable load reduction when you shifted it into neutral, hence saving fuel. How much fuel you save is debatable and IMHO marginal at best. With modern transmissions and computerized controls I highly doubt it will make any difference.
The only other theoretical benefit could be less wear on on the rest of the driveline because the brakes are fighting the engine but again its negligible at best.
I still pop it into neutral because on our vehicle it allows the idle to come up a bit and it runs smoother so it "feels" better to me. We have extreme winters here as well so a few more rpms also runs the alternator a bit higher to provide a tiny bit more charge when the heating is running hard.
Its personal preference honestly.
EducationalBike8090@reddit
stopped at long light. place car in neutral. light changes. you forget car in neutral and step on gas to go. engine revs. ccar doesn't move. you forgot in neutral. drop in drive. CLUNK.
shadracko@reddit
If you're your going to go to the trouble of shifting, why not shift to P rather than N? Seems to make more sense to me.
True_Goat_7810@reddit
because to get out of P, I need to step on the brake. And i have to get over N and R, and push the stick to the side...
N to D and back is one click.
shadracko@reddit
Alright. If shifting "all the way to P" is a significant inconvenience, I think we're overanalyzing this.
True_Goat_7810@reddit
I do this at every red light, so yeah.
loweexclamationpoint@reddit
Yeah. Around here at some lights if you show up just when they turn red, it's an eternity for 2 green arrows and 1 green the other way. Wears your leg out staying in D. That's why yellow means go like hell around here too.
BruinBound22@reddit
Auto-hold or go to P
loweexclamationpoint@reddit
Yeah, I do P especially if I'm distracted by Reddit while I'm waiting
SourcePrevious3095@reddit
Neutral, the only true way to disable auto off/on in my malibu.
TC_SnarFF@reddit
You should learn and watch how a fl torque converter/automatic transmission work in relation to a clutch/manual transmission.
There is absolutely no reason to be shifting an automated transmission to neutral at a light. An argument can be made for doing so with a manual.
Comfortable_Client80@reddit
The answer is vastly dependent on the tech of the said “automatic” gearbox. Is it a torque converter? Single clutch? Dual clutch? Any kind of hybrid? The answer will be different
SparkeeMalarkee@reddit (OP)
The two cars I drive are a 1998 ford van for work and a 1995 Jaguar for leisure, so these are old school three or four speed torque converter planetary contracting band units
Popular-Arm@reddit
Why not put it in park? Solves all your problems even when it's not flat ground.
One-_Buzz@reddit
Why? I don’t see the purpose of doing it every time, just to shift back into D to go.
I do it sometimes if I know the light is multiple minutes long and I want a break. But definitely not every time.
Overall, it won’t hurt anything to do it constantly, but I just don’t see a purpose.
WizeAdz@reddit
The way automatics try to creep forward when stopped has always annoyed me because I learned to drive manual first. With a manual, the car only does what you tell it — and having a car move I didn’t command it to do feels dangerous (when people are using crosswalks in front of me) and unnatural.
The good news is that I’ve moved on entirely from both and drive mostly EVs now. EVs usually have lone pedal driving”, which means the car stays stops and stays stopped when you let your foot off of the go-pedal. (Software applies the friction brakes gently somewhere under 3mph, above that speed the deceleration comes from regenerative motor braking.) Doing it this way feels very natural in an EV once you get used to it.
We all have our peeves, I guess, and EVs trample on fewer of my automotive peeves than automatic transmissions do.
DFLDrew@reddit
Not holding the brakes while you’re stopped is far more dangerous than whatever you’re talking about. If there is a crosswalk in front of you, in what universe is it safe to sitting there in neutral?
True_Goat_7810@reddit
Whats the scenario here that isnt unsafe?
At least the car doesnt move if your foot would slip off the brake or on the accelerator? Why would beeing in gear (ready to drive on the crosswalk if you take the foot of the brake pedal) be safer than out of gear (taking the foot off the brake will probably do nothing if you are on flat ground, or the car will start rolling very slowly)
that_dutch_dude@reddit
what kind of peasant are you to hold the brake constantly? if the converter is disconnected the car doesnt want to move unless you are on a incline. and even then you only have to press hard enough to stop the car from rolling away, you dont have to press harder to also work against the torque converter.
shadracko@reddit
What's the issue? Especially compared to lightly holding the brakes, as most people do in an automatic?
morningstar243@reddit
car won't creep in N
Ancient_Persimmon@reddit
I don't drive automatics much, but I kind of hate creep, so I put it in neutral sometimes.
NewUnderstanding4901@reddit
not bad, just silly.
BouncingSphinx@reddit
There's no reason to put it in neutral at a light, and honestly it might be slightly worse to do so due to more shifting in and out of drive gear.
bradland@reddit
The reason you get conflicting answers is because you're at the margin of what makes a meaningful difference either way.
Using a car at all causes wear. Is wear "bad for" a car? So should you stop using the car? Of course not.
When you leave the car in D, the transmission selects the lowest gear and leaves it engaged. The engine spins against the resistance of the torque converter, which is a fluid coupling. The only "wear" is heating of the transmission fluid. The parts in the transmission remain under a static strain load, but this type of load doesn't cause much wear at all. Strain + movement = friction, and friction is what causes the kind of wear that requires eventual repairs.
When you put the car in N, the transmission uses internal clutches to disengage all gears. There is some slip when the clutches disengage. That's strain + friction. When you put it back in D, those same clutches engage.. That's strain + friction. So the act of switching to N and back to D operates the clutches two additional times when you stop.
Does this matter? Your transmission clutches operate every time it shifts gears. This happens thousands of times over the life of the transmission. Analyzing how much additional wear you're putting on your transmission by shifting in/out of neutral is an exercise that would require a lot more data. If you do a lot of city driving, your car is already doing a ton of shifting. Adding a couple more shifts won't make a meaningful difference.
The other potential impact of shifting D, N, D when you stop is the shock load of engaging the transmission to drive away. When you leave the car in drive, your entire driveline remains under a static strain load while stopped. This includes your differential, ring gear, axles, CV joints, etc. When you put the the car N, all of that tension is released. When you put it back in gear, there is a shock load transmitted through the driveline. It's a bit like slamming your hand on a desk repeatedly. It causes wear.
Again though, you have to ask how much wear? Is it meaningful? Again you'd have to do a lot of analysis. Some car drivelines are far more tolerant of this kind of wear. Plus, the driveline is designed to handle this kind of shock load. It's not made of egg shells.
Then you have to consider the trade-offs. If your engine is idling rough while in gear, that's shaking the engine and car. That wears out engine mounts and rattles your interior. It also sends repeated shockwaves through the driveline. All of these things cause wear too.
Again... How much wear? Is it meaningful?
Ultimately, shifting to neutral at a stop isn't going to make or break the total lifespan of your car. Nothing I've outlined above crosses the threshold of meaningful wear, IMO. Of course, if you drive a car with a notoriously weak transmission, that might change my opinion.
My advice to you though is to drive the car as the engineers designed it. This means leaving it in D at stops. If your car idles rough while in D, you need to address that problem specifically. You may have an issue with your idle-control circuit. That can be remedied.
Shifting to N at a stop introduces other issues. Like what if you need to pull away quickly? Also, if you get caught off-guard by the light, shifting from N to D, then immediately pulling away can cause the car to lurch in a way that does have meaningful adverse impact.
It's not that the simple act of shifting D, N, D is bad for your car, but that it is a bad practice that causes issues outside of mechanical wear.
SparkeeMalarkee@reddit (OP)
This is the answer I wanted. Detailed and reasoned.
BigBlackMagicWand@reddit
Generally switching to N makes no difference whatsoever. Do it or leave it into D, if you're sitting still the transmission couldn't care less.
In practice there's way more variables in the answer, different transmissions with different means of engagement etc. The actual thorough answer depends on the case.
H_rusty@reddit
pointless in modern cars... nowadays computers can detect when you are stopped in D so leave it in D
Rwood219@reddit
Not at all necessary.
sexchoc@reddit
You get a million different answers because nobody has tested this exact scenario for long term effects. Also I assume nobody knows exactly how your specific transmission model works unless you stated what it was.
My personal opinion is that you're asking your transmission to disengage and engage whatever clutches it uses for drive many more time than it would if it was left in drive. The long term effects are probably negligible, but I couldn't say for sure.
ItzChiips@reddit
What's the go to sporty/fun yet practical commuter? Looking at WRX/GTIs. BRZs probably too small and I need to transport my dogs sometimes. Otherwise just want something I can have fun in sometimes but not dread commuting to work
Butt_bird@reddit
It makes no difference. Just like idling in park.
Don’t ask questions on Reddit if you are looking for a straight answer.
losromans@reddit
Only time I’ve done it at stops is when I’ve just changed my rotors and pads and I’m working on seating them. So, I pop it into neutral and hit the drum e-brake. Mostly bc my brain thinks it’s better for the heat dissipation as I’m accelerating and hard pressing my brakes and trying to not warp them like I did with my old Infiniti.
It may not be the case but, that’s when I do it.
I’ve also done it at a parking lot bc I just needed to stop to send a text but didn’t want to go fully into park. It made sense at the time.
Tundra_Dragon@reddit
Look, you're asking the same group of "knowledgeable car people" who have a 7 step process of setting and unsetting the brake while putting their transmission in park, because they somehow fear the big metal bar that locks you in park will somehow be damaged if you actually use it to keep your car in park.
Automatic means just that. Set it, forget it. Don't go manually downshifting at lights, unless you're hauling the kind of load that somehow can overpower both your brakes, and your trailer brakes. Spoiler: that amount of weight generally takes you over Gross Curb Weight.
The cost of failure for accidentally dropping it in reverse with a car behind you is significantly higher than any preceived savings of either fuel, or preceived damage to the transmission.
On a final note, my truck's transmission has 284k miles on it, and still operates perfectly. One of my WJ Grand Cherokees has 353k on the original transmission without issue. My neice learned to drive in that thing too.
DriveRightCarBuying@reddit
I remember an old story that FoMoCo had to send engineers out to the large taxi depots in NYC to tell cabbies to stop putting their vics in neutral at lights. It was ultimately more wear on the transmission to constantly be shifting in/out of drive. I think there were a few cases of broken column shifters too, since they're not designed to be used 100x times every day.
wpmason@reddit
It has nothing to do with the car.
You’re not supposed to do it because you need to be able to take evasive maneuvers in the blink of an eye if there’s a dangerous situation brewing.
Being the idiot that can’t move their car out of the way because they’re fumbling with the shifter is an easy way to get someone killed.
People are way too lax about how dangerous things can be on the road.
No-Sherbert-9589@reddit
It's bad for the transmission. If you want your transmission to last leave it in drive holding the foot brake at red lights. With a manual holding the clutch down wears the release bearing so select neutral while waiting.
PulledOverAgain@reddit
In neutral you're taking the pressure off of the bands and clutch packs. At which point you would have to apply pressure to them to resume motion. Which means there is some slight movement inside the transmission for these to apply/release. It's not much, but over a long time I would think it would actually increase the wear.
SevroAuShitTalker@reddit
Stick shift- doesnt matter.
Automatics- typically newer ones will reduce fuel flow to a bare minimum when the engine is not under load. Same reason why you leave it in gear when coasting down hills
BoulderNerd@reddit
Yes new cars with auto stop do turn off the engine while stopped with sufficient brake pedal pressure. Typically you can reduce the brake pedal pressure to restart the engine if you want.
JewelerExciting7576@reddit
Can I ask a question regarding n what about coasting down hills?
Total-Improvement535@reddit
There’s absolutely no reason to so why would you?
o0Spoonman0o@reddit
You will get no measurable fuel savings and you are potentially exposing your transmission to more wear. Every time you shift to neutral the clutch packs or bands (depends on the transmission) are engaged. Doing this at every stop light results in a bunch of extra wear on the transmission the it really wasn't intended to see. They do not make these things with the expectation that people are going to be shifting them into neutral constantly.
I'm not suggesting this is catastrophic, but it's unnecessary and has literally no upside. The transmission is designed to be put in gear and drive. Not fiddled about with at every stop light. Sitting in drive with the brake applied keeps everything stable and pressurized as it's designed to be.
Best practice is to leave the transmission in drive until you need to park or go in reverse.
Because anytime you post something to a public forum you get people who - know what they're talking about - have no idea what they're talking about - heard something from some guy somewhere - are sure they understand how this works despite never even looking into how transmissions actually function - etc
KaiZX@reddit
You get so many different answers because there's many different automatics. With manuals you have 1 option, you manually control the clutch and the gears. I'm pretty sure there are a few different examples but that's the main thing that's true for all of them.
With "automatic" you don't control the clutch and quite often the gears, with some exceptions. But the term "automatic" includes so many very different technologies like CVT, DCT, torque invertor, AMT and others. Also different years/models of the same type have different behaviour so there's also a difference on how you should operate it. Subaru WRX CVT is quite different from a CVT in a hybrid Corolla, but they're both CVTs and so on.
JournalistLopsided89@reddit
dont do it, pretty sure it cuts oil pressure in the transmission.
Educational_Bench290@reddit
In the snow, yes, as you approach the stop. Otherwise a waste of effort: the transmission is designed to idle without motion.
silvermoonhowler@reddit
Why even bother?
I'd say the only situation where this becomes viable is if you're in a manual, otherwise, it's just useless if you're in an automatic
What if you don't notice that the light turns green and you step on the gas and forget to shift out of N? See how this doesn't make sense!
WorkerAmbitious2072@reddit
Leave it in gear (drive) when on the road
Fillmore80@reddit
Man watching this back and forth is almost as much fun as watching people argue how a plane flies. Whether due to the force of air hitting the bottom of the wing, or the pressure change between the top and bottom of the wing. In some cases it's thrust alone maintaining flight.
For the record I think it's the force of the air hitting the bottom of the wing. I say this because the pressure differential doesn't explain flying at high alpha. Thrust alone does explain high alpha in some use cases, but not in all.
Jimmy_The_Chin@reddit
I think the reason that you het the range of answers is that there’s no solid reason for or against doing this. It’s just a lot of edge cases where it might make sense if it makes sense to the individual. You’re not going to damage anything doing it and you’re not going to damage anything by not doing it. I had an old Toyota that would idle more roughly at a light when in D so i sometimes shifted to N if I felt bothered. Most new cars it doesn’t make much difference. I would say do what feels good to you.
WeeklySky3512@reddit
It depends on the automatic. Without being overly pedantic when you shift an automatic into neutral, you also stop the torque converter from turning, which in turn drives the pump that circulates fluid through the transmission. Without that fluid circulating over time, it builds heat. The heat buildup can cause your fluid to prematurely degrade
No_Base4946@reddit
You stop the torque converter, which is bolted to the engine, from turning?
Wouldn't that also stop the engine from turning?
viole_8@reddit
The pump is still driven while in neutral. But yes doing it at stoplights is pointless
Ok-Ad8998@reddit
Don't do it.
There is no valid reason to do it (I've read through the responses here. None if them are valid.)
Adds wear to the shift linkage. Minor, but real.
Automatic transmissions were not designed to work that way. You are supposed to leave it in "drive".
Leaves you unprepared to respond to situations around you.
Don't
Manyconnections@reddit
It’s not a manual car stop trying to look like it is. Just leave it in drive lol
badhoopty@reddit
ill do it if i got my ac running just so the engines will be a couple hundred rpms higher and help that compressor out a little.
other than that theres no real reason.
morningstar243@reddit
I do it in my 2008 v50 d5 automatic, you can feel and hear the cars happier along with rev drop for me.
that_dutch_dude@reddit
no.
chuck-u-farley-@reddit
Keep throwing it in neutral at red lights with an automatic “so you can rest your leg”
Gonna be interesting if you get rear ended and pushes your dumbass right into the intersection , all because “your Leg was tired”
Or Maybe you needing to go in neutral “to rest your leg” and you get distracted by something and roll right into the car in front of you or in back of you…. All because your spindly little leg couldn’t take holding the brake for a few minutes
majikmike@reddit
When you're stopped at a light, and some guy comes up too fast behind you, how long is it going to take you to put it in gear and move your car. There is no reason to do it, you're just adding more complication to a pretty simple situation, for no gain.
Hackpro69@reddit
Take a minute and find out how transmissions work (Manual and Automatic). Most people don’t understand the workings.
rzugorzyt@reddit
It depends on desingn of particular transmission - but in general it's not recommended. N is used for towing, pushing and for smooth switching from D to R. In some transmission (probably most of them) in D all forward valves are open, reverse are closed. In R, forward are closed, reverse are open. In N both types are open (oil pressure to low for normal tranmission work) or closed (too high).
It's very trivial explanation to the point being probably wrong, but it should be good enough to show general idea to avoid switching to N without reason.
aquatone61@reddit
Normally there is no reason to do this unless you are stuck in traffic/drive through line for a very long time. I do this in my DSG GTI.
fr30n7@reddit
In your DSG GTI the gearbox disengages the clutch once you come to a stop anyway, so you're effectively in N.
OldDude1960@reddit
Ask long as your foot is on the brake, it doesn't hurt to do it.
oboshoe@reddit
The increased wear and tear on the linkage is WAY WAY more than the increased wear of fluid across the turbine at idle.
Just keep it in D.
TheChair303@reddit
It's your car, do what ever you want.
BoK_b0i@reddit
The only time I do it is to give quick throttle blip when my truck's crank position sensor decides to act up and make the idle go goofy. Other than that, what purpose does it have? The load difference is minimal
IAmMDM@reddit
I won't give you "one concise answer" but here is some food for thought.
First, why would you even do that. When in N, it's not like you can take your foot of the brake and not pay attention to what's going on. In N the car is free to roll e.g. if it's on a slight incline. Sometimes, when the red light is long and the driver needs to do something that requires taking their foot off the brake, they put the car in P. That at least prevents rolling (while also effectively putting it in N from the point of view of the load on the transmission components).
Second, there are many types of automatics and what rule technically applies to a traditional automatic with torque converter may not apply to a CVT and especially to a dual clutch automatic which is much different internally.
Third, car engineering is a very developed science, and they design cars to withstand normal usage. Keeping your foot on the brake at the red light is normal usage. So if there is any additional wear compared to shifting to N, it is probably accounted for in the car's design. On the other hand, shifting to N (or P) on every red light is not normal usage, so some car component may be not designed to take it 20 times a day for 10 years. Just a speculation, but again, normal usage and statistical models of wear are used in car design.
Fourth, there is an additional reason why keeping your foot on the brake (or keeping the car in P) has a benefit. Imagine that someone rearends you when you are stopped. If you car is in N with no brakes, it will be freely and suddenly pushed forward giving you a full force whiplash. If there is resistance from the brakes or the P pin, the car will resist being pushed (to some extent), dissipating more of the impact energy in its rear bumper and rear crumple zone. So it is about what do you value more: your neck and brain, or you trunk and bumper.
brabson1@reddit
I'm not trying to have the converter engaged an extra 5000 times tho
edwbuck@reddit
In the really old days, shifting control systems were primitive. So primitive that manual transmissions basically had the human train to learn the algorithm.
In those days, the engine would slightly pull the car forward when it was attached to the transmission, because even if was "gear reduced" to a tiny amount, the car would pull forward (or reverse if in reverse). To fix this, a person would "press the clutch" temporarily disconnecting the engine from the transmission. While that's a solution, riding the clutch (constantly using it without fully pressing it, to create controlled slippage) had its own issues.
As these people eventually learned how to drive automatic trasnmissions, they carried in their heads a lot of algorithms about how to best approach an intersection, accellerate up or down a hill, control the car's speed in a curve, etc. Driving was much more of a skill. They would take their knowledge and apply it to cars in weird ways, and shifting the engine into Neutral is meant to simulate pressing the clutch to prevent the car from creeping forward. But automatics aren't designed to be shifted the number of times a manual transmission is, so odds are they're just accelerating their time to the next service.
That's a long winded way of saying, "don't do it, unless you're going to be there for a long time, like five minutes or more, in which case... maybe turn the car off instead so the wheels will lock and you don't have to ride your breaks, which also wears out cars prematurely."
But time marches on... now cars are turning themselves off at street lights... again they're designed differently, and that doesn't mean that misapplying ideas that were good in the days of manual transmissions to cars that lack a manual transmission will be a good idea with modern cars either.
Timendainum@reddit
What kind of crack do you have to be smoking to want to do this?
EducationalBike8090@reddit
an age old question. doesn't hurt to leave it in gear. It made to do that.
thehighmonkeylife@reddit
Like life.. it depends. On. The. Car.
boatsnhosee@reddit
Sounds like a pain