invincible569

This past weekend, I asked my wife to drive next to me on the freeway to see what her speedometer read in our Honda Accord (stock). We noticed that the TL with 20" wheels was 5 miles below what the Accord read. For example, the TL was going 75 while the Accord was going 80. Has anyone else tried this? Now I really have to slow down when I see a cop.

Boardman

I haven't tried it on my TL although I have had similar experiences with aftermarket rims and tires on prior cars. I always use this calculator to find out how much different my speedo will be with aftermarket tires before I buy the tires

http://www.miata.net/garage/tirecalc.html

If you put the stock tire size and the aftermarket tire size in it will tell you exactly how off your speed should be.

HiTEC

yea... you always want to keep your overall rolling diameter as close ot stock as possible when you change your wheels. I always shoot for less then 1% difference.

The link Boardman posted is the primo calculator online