I play with the pressures to get the balance of the car to my
liking. Now, mine is a race car with vintage racing tires so the
pressures aren't applicable to the street very much, but I found that
if I dropped the rear pressures I could get the car to corner with a
little bit of oversteer which can be fun and fast. The normal
"higher in the rear, lower in the front" seems to induce understeer
in my experience. I dislike understeer intensely, so play with the
pressures in my toy cars to where that isn't a problem. Now my VAN,
I want certainly DO want to have understeer.
FWIW, I run 25 front and 23 rear with Hoosier Speedsters (cold
pressures). If I'm too sideways I'll bump it up to 23.5 rear. When
I ran Toyo Proxes they liked 38 to 40 PSI. Street tires seem to have
"floppy" sidewalls, so higher pressure to a point gives more crisp
handling. I tend to run my street tires near the max rated pressure
imprinted on the sidewall of the tire.
Tony
At 06:41 PM 8/30/2011, Randall wrote:
> > If you run that much pressure the contact patch area will be greatly
> > reduced and you will wear out the center of the tread first.
>
>My experience with radials has been that, although the center does tend to
>wear out first, the overall wear rate is usually reduced. The tires
>actually last longer even though they wear a bit funny. Fuel consumption
>usually improves a bit, too.
>
>Running higher than recommended air pressure also seems to improve handling,
>both responsiveness and ultimate cornering power. Too much can cause
>handling problems though, including instability at speed and vibration.
>
>So my approach in the past has been to start at the maximum pressure on the
>sidewall, and carefully evaluate handling. Then cut it by 4 psi and try
>again. When the handling starts to get worse, you've gone too far.
>
>Don't forget to let the tire cool thoroughly before checking pressure. The
>measured pressure will definitely go up when the tire is warm; how much
>depends on just how hot it is inside the tire. The sidewall rating is
>"cold".
>
>If memory serves, last time I went through this exercise, I wound up at 32
>front and 36 rear. But that was some time ago, and with unusual size tires,
>so may not apply to you.
>
>You also failed to mention what aspects you want to emphasize. Lower
>pressures tend to give better ride quality and less noise/vibration (which
>is the reason most OEMs go as low as they can on recommended tire pressure).
>
>Personally, I drive the car because it's fun, not because it's cheap to
>operate.
>-- Randall
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