> noticed a while back some one mentioned that you should run 20 lb. of
pressure
>in the front tires and 24 lb. in the rear tires on a TR6. That agrees with a
>spec. sheet that I copied from
< snip>
>However the AVONs that came with
>my car have a 35 max PSI, which is the pressure I've been running them.
< snip >
*************************************
This is not meant as a flame, but it just kinda reminded me, and I thought
I should send this out to the list in general. The PSI rating on the
sidewall, as many people mistakenly assume they should inflate their tires
to, is NOT what you should be running on your vehicle-this is a MAX
pressure that that particular tire can safely handle. The actual tire
pressure is in either your vehicle handbook, a plate on or in the vehicle
or in your owners manual, or workshop manual. Typically is more like 24
front 32 rear with the exception of truck tires which will usually handle
more pressure and are inflated higher because of intended load capacities,
or possibly front drive vehicles. The vehicle manufacturers recommendation
should be adhered to especially with stock tires/rims. These settings are
base on drivability, handling and tire wear for the normal loading on that
particular vehicle. In the example I gave you these settings for the GT6
were to provide a measure of understeer for a more controllable vehicle. I
typically run 21 PSI front and around 26 rear on my Spitfire, but I have
much larger tires and a modified vehicle, and after much fiddling these
were what I found to be the best for my driving style. Many things will
affect what tire pressures you will need to run, but it is rarely at the
max pressure printed on the sidewall, and in NO CASE should you run more
than what is printed/molded on the sidewall. Sorry for the winded post,
but I so often hear people say that they inflate their tires to whatever is
on the side wall, and then wonder why the center of the tire wears out
faster than the rest of the tread-or why their car rides so harshly. In
answer to the above, if you are running the same size or similar size tire
then yes, start at 20 front and 24 rear. I think you'll find a much
improved ride, and increased tire life. To improve the handling at the
expense of the aforementioned, you can try an increase of say 4 to 6 lbs
over the stock pressures-but these settings are typically arrived at by
running at speed over a controlled course, measuring the tire temps, and
readjusting until temps are optimized-not just guessed at-
Barry Schwartz (San Diego) bschwart@pacbell.net
72 V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire
|