LAC: Wow! Tire Pressure!

[Alex Kowalski]

On 7/31/06, Jason Kohls wrote:
>
> On 7/31/06, Alex Kowalski wrote:
>
> > The improvement in the handling that came from bumping those pressures
> into
> > the upper end of the "recommended" zone did wonders for the handling of
> the
> > car.
>
> Which is something that eludes me: should you go by the recommended
> psi on the tires or on the vehicle?  And what about plus sizes?  I
> read the "Tyre & Wheel Bible" online and he basically says "jack it up
> as high as it can go" for better fuel economy (I think he had it at
> 40psi, the max of the recommended psi).  I've never quite figured out
> what the proper pressure should be for street and/or track
> applications.
>
I always follow the maximum recommended inflation pressure on the tire, but
then again, this car is not a track car.  It's running the stock 15" Audi
Turbo wheels with 205/60x15 tires (Bridgestone HP50) which have a max.
inflation of 44psi on the sidewalls.

Right now I have the fronts at 38 psi and the rears at 36psi.  I might bump
them up a few pounds just to experiment, but I won't go over 44.  On a tire
this narrow and tall by modern standards, most of the improvement in
handling I talked about must come from a reduction in sidewall flex.  I
think this pressure is probably where I will stay for most of the driving I
do with the car right now -- spirited driving up to about 7.5/10 on the
insane-o-meter but also taking into consideration that I live in an area
with quite a few badly maintained/unimproved roads with lots of frost heaves
and pavement irregularities.

Someone please expand on this if you have other suggestions...and I am
getting a set of 16" wheels for this car in a few months.

Alex Kowalski
'87 5KCSTQ
'86 5KCSTQ