Can a Yaris fit 13" wheels??

[TheRealEnth]

Except if you don't adjust the aspect ratio for the minus-2 sizing, then you will have higher gearing which will improve acceleration at the cost of top speed.

are you saying aftermarket rims/tires, if not adjusted to correct size, causes loss in top speed?

[CASTREX]

Originally Posted by TheRealEnth

are you saying aftermarket rims/tires, if not adjusted to correct size, causes loss in top speed?

I think he was just going by the general rule of thumb.

Shorter ratios foe better acceleration and longer ratios for higher max speed... although is not as simple as that....

[RUFFSTUFF]

Originally Posted by CASTREX

I think he was just going by the general rule of thumb.

Shorter ratios foe better acceleration and longer ratios for higher max speed... although is not as simple as that....

Actually it is. If you change nothing but the diameter of the wheel and tire, acceleration and top speed will change accordingly. And oh yeah, your speedometer accuracy will also be affected. The diameter of your wheel and tire is based on the rim size, the tire width and the aspect ratio. This overall diameter multiplied by pi will give you an approximate rolling circumference. I say approximate because without taking a physical measurement, you're left with the manufacturer's size rating and they are not very good at providing good measurements. Tires labeled as the same size can actually be quite different, even within the same manufacturer. On my Mazda3sGT, I went from a 205/45-17 OEM to a 205/40-17 Fuzion tire. It was a noticeable change in acceleration (quickness). Top speed originally was limited to 114mph on the speedo (112mph GPS)... the rev limiter still kicks in at 114mph on the speedo, except that it is now only 105mph on the GPS. Keep in mind that speedos do not report actual speed, much like gas gauges don't report actual fuel level... only different. :)