Redo Tune???

[60sec_assassin]

I plan on changing out my rear tires from 245/55 to 255/55. I current have a tune on my car, will this change in tire sizr effect any of the tune settings?:confused:

[burt ragio]

By changeing tire size apx .05" the only real change will be the spedo reading.

[LilCop2002]

If you have a tuner, you should be able to adjust for the 1mph at 60mph difference by changing the revs per minute of the tire. You should be able to find that new number on the tire manufacturer's website.

[merc6]

who's tune did you have? Lidio usualy has a 3.55 and 4.10 tune as well as the option to change tire and axle rpm

[ctrlraven]

You can correct the speedo if you have an xcal 2 unit. 255/55 Revs Per Mile are 695 (closest the unit can get to).

[LilCop2002]

Nittotire.com shows that my 255/55/18 NT420S tires are a 718 revs per mile...

[Black Terror]

Do the math with a calculator and you will see that 718 revs per mile is incorrect, 694 is the correct value. The Nittotire.com calculator has always been wrong, don't see why they can't correct it.

[ckadiddle]

I have had 255/55s on for a long time now. Played with correcting the revs oer mile on the xcal2, couldn't tell a difference. I think the odo diff at 60 mph is avout one MPH IIRC, so hardly bears bothering with.