CRAIGFIN

If you upgrade from a standard 16" wheel and tyre up to an 18" wheel and tyre then you must surely cover more ground over 1 complete revolution.
Wouldn't this then mean that your trip and speedo would read high??????
If this is the case then can the speedo/trip be recalibrated?
What have people noticed?

Cheers,

Craig.

Attu

The lower profile tyre on the 18 inch wheel would make the rolling circumference about the same as the 16 inch wheel with the higher profile tyre.
The speedo may not read 100% correct with the new wheels but it wont be far off and they are never correct any way.

Andy

RON

There's a website with a calculator on it somewhere, put up another thread asking specifically for that, and someone'll know it!!

Mickle

here it is http://www.miata.net/garage/tirecalc.html

Mickle

or this one if you don't have a second size to compare to http://www.dsm.org/tools/tiresize.htm

CRAIGFIN

Cheers fella's,

Just what I needed. Thanks to John as well for the email.

Craig.