Peter Doherty <peter@acranox.org> wrote:
> I also like this one so you can set the gears:
> http://gs.tolan-hoechst.com/tirecalc.htm

> Although, personally, I crack out a spreadsheet and generate the formulas
> myself (not hard at all if you think for a bit).
> but you can't adjust the speedo, you can swap the speedo, with one from an
> EX, for example, which might have stock tires close to that size.
> Since most speedos under-read to begin with by about 5%, maybe more, (my 94
> CX was closer to 10%) you may have increased the accuracy of your speedo,
> but that also means, that if you used to cruise down a 35MPH road at 45, but
> were really only going 41, a cop may not care, but now that you are actually
> going 45, you could get pulled over.

When I compared my speedometer reading with a handheld GPS receiver, I
found that the speedometer on my '93 Accord read 3% high. Presumably,
this means that my odometer is 3% high too. The tires that came with the
car are 185/70-R14, which seems a little small compared to other cars
in its class which seem to come with 195's. If I changed to 195's, I
would cause my speedo to read 5.4% lower that it is now, and 2.4% lower
than true, so maybe Honda intentionally calibrated the speedometer to
fall between 185's and 195's so they could have the flexibility to use
either sized tire with reasobale accuracy.

Andrew