Re: wheels/tires for Coupe GT

[Allan Jones <ampj@tiac.net>]

> >Just did some quick calcs on tire sizes.  Someone's been mentioning
> 195/55/14's.  That works out to be a little less in diameter than even the
> stock 185/60's.  I would think if your gonna pop for $106 per Dunlop SP8000,
> you'd want a little bigger tire than stock to improve appearance as well as
> performance.

	No. What you get with 195/55s is a slightly lower sidewall height,
which means a lower profile(desireable!) tire, and I believe a very,
very small increase in the tread contact patch(also desireable!), so one
actually does "improve appearance as well as performance" when changing
the stock 185/60s to 195/55s. Also, 195/55 tires are almost always
either "V" or "Z" rated, so the performance gains are tangibly real!

> I think that is backwards?  a smaller  diameter tire gives a shorter lever
> arm, raising engine speed relative to road speed - hence more power at a
> given speed, no?  a smaller tire is like a slightly lower geared
> transmission.  My coupe had 195/60's for ages until I put Erie's 185/60's on
> (the correct size)  Now my speedo is correct 

	More power too?! Cool! ...I run 195/60s on my CGT and would never
return to the stock size. Huw, why did you do so? Actually, I think a
rather humorous way of determining if the owner of a parked or a
'stopped at a red light' CGT(or any 4k for that matter) is "into"
performance gains is by looking at that tire #. A 195/60(or /55) tire
upgrade is the simplest and easiest change to gain a minor performance
advantage, but more importantly in my eyes, is a very noticeable visual
improvement. Do not read that wrongly, i.e. as I consider visual more
important than performance improvements. I simply think the change to
195/60 offers hardly any noticeable performance gains, but the change
does greatly add visual impact. Thus the ONE single reason for the
upgrade would have to be looks, with an added benefit of some increased
traction. If one switches to a 195/55 "Z" rated tire then I think the
performance gains would be at least on par with the visual gains. Has
any CGT owner done this?
	One more thing, the affect of running 195/60s instead of stock tires on
my digital speedo. I believe my speedo now shows a slower or smaller #.
The tire is not turning as many times to achieve the same speed. So if I
have seen 126 MPH, assuming the instrument was perfectly calibrated of
course, then I was actually going faster, right? I can and will try to
figure the true speed out(in a perfect world, i.e. 126 on 195/60 tires
with no other factors) but want to know if a lister also can so I have a
reference answer.
						TIA! Allan