Do 16' stock rims give me better gas mileage than 20' custom rims?

Question

i have 20' on my car but i wanna save on gas so i was thinking of putting my stock rims back on so i can save gas money but i dunno if it even makes a difference

Answer 1

It is a good question indeed.
I myself would say that generally, the smaller, lighter wheels will get better mileage in everyday driving, say around city and the such.
This is due to the fact that there is less mass to get moving each time you pull away from a stop, meaning less fuel will be needed.
But in theory, it could also be said that the 20' rims would be better on the highway.
Because the 20' rims would be travelling faster then the 16's, it could be said that you could in fact back off on the throttle, which would help save fuel.
Let's say you have a 4 speed automatic. When travelling at 100km/h(I'm Canadian) with 16' rims,the engine might be doing about 1900rpm.
But with 20' rims, the difference could be as much as 6%, meaning when the speedometer says 100km/h, you'd be doing 106 at 1900rpm. If you back off to compensate for the difference, you could drop the engine down by maybe 250 rpms, which would, again, in theory save gas.
But I'd say that if you want to save gas, go with the smaller and lighter rims.

Answer 2

The first person who answered, answered correctly. 16 inch stock rims will give you better fuel economy, but only because the tires have less profile or footprint and therefore less friction on the pavement to move and less friction from wind that hits the front surface of the tire as it moves. As for the other aspects of your vehicle, like brakes, suspension components, etc, if your vehicle didn't come with the larger wheels, you probably didn't get the beefier suspension components either and these will wear out prematurely with the larger wheel and tire. You have most likely violated your vehicle's warranty from the manufacturer and your speedometer and odometer have been affected as well, unless you went back to the dealer or a garage and had the gear ratio changed to reflect the increased wheel and tire size. That's the cliff notes version, believe it or not!

Answer 3

there are a few more variables involved but generally yes your stock will get you better gas mileage vs 20's. Plus your tires will be hella lot cheaper.. trust me..

when you get into larger rims you have to account for braking, allot of idiots who get 20+ rims don't even think twice about stopping times.. bigger rims=bigger brakes
not to mention center of gravity is changed I can go on and on..

Answer 4

its a good question..

one part of the equation says that the bigger the wheel, the farther it goes. For example: your 20's are going to move your car a little bit further for each rotation of the drive shaft than the 16's.

but there are other factors like torque, inertia, etc that may counterbalance or even exceed the "benefit" of the larger wheels

Answer 5

It will make a big difference. There is less mass of weight for the car to move. Your acceleration, braking and handling will also improve.