Better mileage with smaller wheels

[Doraemon76]

I own a 95' Integra LS and recently replaced my 17" wheels with my factory 14" wheels. I know upgrading to bigger wheels will insue inaccuracy in the speedometer to the actual speed you are going, but does it also affect the actual distance you are travelling? Or is the bigger wheels (with more weight) actually causing lower gas mileage?

Thanks for all your insights.

[SumAznGuy]

Basic answer is the 17 inch wheels will require more energy to get going when compared to the lighter 14 inch wheels. If you do a lot of stop and go traffic, the heavier wheels will cause you to use more gas when you start going. And the heavier wheels will put more wear onto your brakes since it will take more braking to slow down the heavier wheels. But we only might be talking about 5 or 10 % at most. So a difference of 2 - 4 L of fuel consumed over a 40L tank.

Tires also impact fuel economy too. If the stock tires are 195 wide with a 300+ wear rating compared to a wider 225 tire with a 180 wear rating.

If you do a lot of highway driving, the taller 17 inch wheels will slow the speedo but will also slightly improve fuel economy, but again most likely by single digit differences.

Mind you, a lot of it also has to do with the type of driving and your transmission. If you can cruise in a higher gear while maintaining 50 km/h with a shorter wheel, then your mileage may also improve.

As for performance, if the stockers are 23 inch tall, by going to a 21 inch tire, that will shorten the gears and improve acceleration. If you were to go to a taller 25 inch wheel, then that will have negative affects to acceleration, but the shorter sidewalls might slightly improve cornering.

[Doraemon76]

You are absolutely right, I get about 450 kms on my 17s and 500 kms on my 14s on a full tank of gas.

Since I get around 11 kms / litre, that equates to a difference of 44 kms between the two wheels.

Better acceleration is definitely achieved with the smaller wheels, but you lose handling.

[hchang]

Sorry for thread jack,

But will the size of your tires change the amount of kms traveled recorded on the car?

[whitev70r]

I think it depends how close you are to stock sizing. check this handy tire calculator comparison from 1010tires http://www.1010tires.com/TireSizeCal...?action=submit