Can you handle yet another question about premium gas?
Posted by Haunting_Repair1776@reddit | askcarguys | View on Reddit | 14 comments
I have a 2025 Mazda CX-5 NA. It's my first new car in 22 years and I plan on keeping it 10 to 12 years. Here are the parameters of my question:
I don't care about maximizing performance. I don't care about cost of fuel, nor miles per gallon. I only care about minimizing carbon deposits and extending the life of my engine. I have a very short commute to work. Right now I'm putting Shell V-tech nitro premium gasoline in it, for the added detergents,even though its not a turbo. Will this help me reach my goals or not?
D3f1n1t3lyN0tMyAlt@reddit
Regular is recommended for that car, premium provides no benefit. However, top tier or equivalent detergent blends (which basically any of the big brand gas stations have) is beneficial.
PaysOutAllNight@reddit
No. Detergent packages in any "Top Tier" fuel are similar. You're wasting money by buying premium for benefits it simply does not provide.
All oil companies would like you to believe that there's a better detergent package and more power in premium fuel, but it's simply not true.
LightEarthWolf96@reddit
Didn't know about top tier fuels but it turns out I've been using top tier fuel anyways because sunoco offers the cheapest gas in my area and is also in a convenient location. Good for me I guess
AdditionalAd9794@reddit
Regarding detergents alot of small engines, leaf blower size, really don't like chevron because they put too much detergents in.
I've always wondered and suspected, maybe it could also be detrimental to larger car sized engines
E90BarberaRed6spdN52@reddit
Premium is a waste of money here and for your goals. Take the car out on the highway occasionally and do an "Italian tune up" blowing the carbon out. Also you are better to put your money into more frequent oil and filter changes. Say every 5k Miles...
Many_Hotel866@reddit
Short trips are brutal on your engine, oil and battery regardless of fuel choice. Ensure you're properly taking it for a long drive at least weekly. I'd also change the oil more often.
How short are we talking? I'd honestly get a cheap small off lease EV for something like that (or even a bicycle)
Signal-Confusion-976@reddit
Use what your manufacturer recommends for octane rating. You will be wasting your money using a higher octane. Just keep your car well maintained. If you feel you must there are some decent fuel additives you can add if you want. But most fuels come with detergents and additives already.
Immediate-Event-2608@reddit
You've gotten good answers about fuel, but I'd just like to add that if you have a short commute you should also make sure to do some longer trips as well, even if they're out of the way.
Short trips can result in condensation building up in your oil, to get rid of this you need tub get the oil up to operating temperature and then keep it there for 20-30 minutes.
jtfarabee@reddit
Stay ahead of your maintenance and don’t put crappy fuel in there, but you’re fine with regular. If you really want to make a difference, buy non-ethanol fuel instead of wasting money on premium.
I’ve got a 2013 Mazda3 Skyactiv with 209,000 miles. When I bought it I did a little test to see if it ran better and got better mileage on premium. It didn’t. In fact, it was worse. These engines are designed to run on a certain octane level, and outside that range they lose efficiency. Turbos benefit from premium being forced induction is more likely to create fuel knocking, and the higher octane has a higher detonation point when adding in heat+pressure.
Any additives or “upper cylinder lubricants” are pointless in a DI engine. The fuel never flows through the valves, so all that stuff is wasted. You just want something that’ll burn well and burn clean.
Non-ethanol (E0, rec fuel, etc) is an improvement for 2 reasons. One is that ethanol is hydrophilic, meaning it can absorb water and allow water into the fuel system. While modern engines are designed to withstand E10 or E15, if you’re willing to spend the money it’s always better to not have something harmful than depend on the safeguards that keep it from doing damage.
The other advantage to E0 is back to octane. Ethanol has higher octane than gasoline, so when you have 10% of the fuel coming from ethanol you get an octane boost, and the gasoline can be less refined. Most of the time this doesn’t matter, but it does reduce fuel mileage, because ethanol doesn’t have as much potential energy as gasoline. It burns better, but doesn’t have as much power.
Tl;dr, your car will run best on regular unleaded. If you want to be bougie give it non-ethanol.
PaysOutAllNight@reddit
Your post is mostly correct, but ethanol doesn't "allow water into the fuel system". It binds with water and actively removes water from your fuel system. Ethanol blended fuels aren't coming from the refinery pre-tainted with water.
Before ethanol blended fuels were common, it was very common to see additives for sale to remove water from your fuel system. These were especially common in cold weather climates where water in the bottom of your fuel tank could possibly freeze overnight and block the pick up line. Those water removing additives were almost always ethanol based.
Anyone who runs non-ethanol gas in their car should consider getting a few gallons of ethanol blended fuel once or twice a year. When blended in gasoline, besides removing water, ethanol is a cleaning agent that removes alcohol soluble contaminants and buildups.
I also doubt that fuel destined for ethanol blends is any less refined than other gasolines, but don't currently have time or interest to research it.
Cyberdink@reddit
Modern engines have direct port injection now. No more washing your valves with gas every intake cycle. Id say, yes, the best quality gas will help minimise carbon deposits. Don't hold many extra months or years it'll make the engine last
galactica_pegasus@reddit
Depends on the engine.
Toyota/Lexus still use multi-port fuel injection in some of their engines (along side direct injection).
chumlySparkFire@reddit
Changing the oil twice as often as they say is far more important than the gas
Heavy_Gap_5047@reddit
Yes, Shell V-power has a higher level of detergents and upper cylinder lubricants in it. The fuel won't do anything for deposits on the intake valves, but it appears that isn't a huge deal for that engine. What should be done though in addition to the fuel is a long hard drive on occasion to clean it out.