Would it be pointless to put all terrain tires on a fwd car ?

3 percent mpg drop is average when going AT vs highway tires, and can be worse with mud tires. Not an exact equivalent but mileage dropped for me by 10 percent (average 20 down to average 18) switching from summer to M+S on a Ranger 4x4. How much of that was winter v summer v tire I don’t know but it was noticeable. Unless you are finding yourself often in driving conditions where traction is a frequent concern, stick with road tires. If it’s cosmetics as the major concern, look for a road tire you like the looks of.