getting bigger rims = odometer/speedometer changes?

[ddongbap]

Originally Posted by CASTREX

0.1% is way inside the margin of error of your speedometer.

The general recommendation is not to exceed +/- 3% tire size diff.

Also, you will track you MPG over the distance driven on one tank of fuel right?

So, if your tank goes for 350 miles. 0.1% of 350 miles= 0.35 miles.

If your car does 40 mpg that means a difference of 0.00875 gallons per tank.

Again, 0.1% is nothing

Paper MPG and actual MPG can't be rated the same as difference in tires sizes. You never know, the 1% difference may help the MPG.

You also gotta look at the larger picture. 350 miles is probably a tank of gas.

You gotta compare it to 1000, 10000 or so miles. It'll add up. But 1% doesn't bother me personally. Cause IDC either way, since I plan on keeping this car forever. Or till I run it to the ground.

Btw, you have to weigh the entire package. Rims with tires. I don't know how 15 inches get better gas mileage, but weight is weight. Though you gain more metal, in 2 inches you lose 2 inches in tire. I'm not sure which weighs more, but one thing for sure, if you get WIDER tires you'll surely get a ding in gas milage.