Date: Mon, 23 Jul 2001 22:43:24 +0100 From: Johannes H Andersen <johsnopsamsafish.com> Subject: Re: Reprogramming ECU for 17" wheels
Davo wrote: > > > The overall diameter of the tires does not change, so reprogramming is > > not necessary.....this is assuming you install the correct aspect > > ratio tires for the larger wheels. > > > > > > John Davies > > Monroe WA USA > > Thanks, > > I've been told the diameter going from 205/50/16 to 215/45/17 increases by > 14mm (about half an inch). The 215 tyres are needed as the17" Aero rims are > 7" wide, compared to the present 6 1/2" rims. > > I think the speedo will under read by about 3kmp/h (1-2mp/h) at 100kp/h > (60mp/h) ?? > > Anyway, do you think the ECU can be easily programmed? > > Davo A while back somebody posted this useful tyre/wheel calculator: http://www.miata.net/garage/tirecalc.html The speedometer reading will be 2.27% too slow. Johannes