Does anyone replace the stock 195-70 14 OEM rims and tires with say a 16" rim with a 40 series profile so that the new tires and rims would have the same diameter as the stock 14's with the high profile 70 series tires. If so what would be the right combination to keep the speedometer still reading correctly. Also, what about the width ? How wide should I go. The stock 195 width seems pretty narrow. Wouldn't , say, a 235 width be ok ? I'm talking about putting some performance tires on these rims for use, primarily, at the track. Any input would be appreciated. Thanks, Kurt :chug:

 

16" are the best performing but i wouldnt go any smaller than 45 series.. if you run with 40 series the side walls are too small an if you hit a speed bump you run the chances of damaging your rim.. also you can go pretty wide. depending on your rim width and offset. one of my friends were running 15" 50 series with 245 wide..

 

On the fronts a 7" rim is about as wide as you can go without doing a coil-over conversion.

16x7's in the front and 16x8's in the rear with 225/45's on the front and 245/45's on the rear is totally doable without flares. You'll want to do the measurements first before committing to the purchase to make sure you're ride can clear them but this will keep you pretty close to the stock diameter to keep your speedo correct.

17" tall rims are all the rage right now because of their availability on the rice rockets but that's going to be a pretty short sidewall with a pretty rough ride.

Remember, everything from the ground to the frame mount points is part of the suspension and the sidewalls of your tire provide more damping than you would expect.

This website will help you with your calculations. About halfway down is the 'tyre size calculator'. Put in your original size and your new size and it will calculate the speedo error:

http://www.chris-longhurst.com/carbi...yre_bible.html

195/75/14 to 245/45/16 is only going to create a -3.27% error or 67.71mph when your speedo reads 70mph or 96.73 miles driven for every 100 miles on the odometer.

That's pretty mild in my opinion. If that's outside your margin of error, once you've decided on your size you can always have your speedo re-calibrated to make up the difference.

 

That's what I'm talking about. Thanks for the very informative answer. Kurt :dancing:

 

LWW-Excellent info. Thanks.