Tire pressures

[houndman]

With the price of gas so high, I decided to up the pressures from the
lower than factory ones I was running in my 2.5i, because the ride was
TOO rough when driving on any patched streets. I didn't get a WRX,
because on a 1 mi test drive, I couldn't wait to get out of it and
into my old Chevy.

I figured I'd just stay on main streets through the city which
aren't patched as much. I was running 30 fr/24rr, which was the same
ratio of the pressures to the unloaded fr/rr weight of the car. I was
just going to do with the 33/30 recommended, but decided to try 35/32,
to see what it did for mileage, and then dropping to the 33/30 and
compare. The car doesn't Hop on the lumps in the street like it used
to feel like. Maybe the suspension has broken in, though only 2700mi
on the car, or maybe the seats have, since they don't feel as hard, Or
my back isn't as sensitive. I have weak muscles and have been wearing
a back support before my back starts to tighten, which means, most of
the time.

VF

 

[Tony Hwang]

With the price of gas so high, I decided to up the pressures from the
lower than factory ones I was running in my 2.5i, because the ride was
TOO rough when driving on any patched streets. I didn't get a WRX,
because on a 1 mi test drive, I couldn't wait to get out of it and
into my old Chevy.

I figured I'd just stay on main streets through the city which
aren't patched as much. I was running 30 fr/24rr, which was the same
ratio of the pressures to the unloaded fr/rr weight of the car. I was
just going to do with the 33/30 recommended, but decided to try 35/32,
to see what it did for mileage, and then dropping to the 33/30 and
compare. The car doesn't Hop on the lumps in the street like it used
to feel like. Maybe the suspension has broken in, though only 2700mi
on the car, or maybe the seats have, since they don't feel as hard, Or
my back isn't as sensitive. I have weak muscles and have been wearing
a back support before my back starts to tighten, which means, most of
the time.

VF

Hmmm,
Not considering premature of uneven wear of your tires? If they are
inflated too much over or under the rating you can mess up the even tire
tread wear. Under inflated tires can over heat. You know what it can
cause on prolonged high speed cruising. You don't drive on highways?
Under inflation can be dangerous. Too over inflated, you lose
control/handling. What's wrong with WRX? I have one in the family.
Kids drive Subaru, I am a Honda man. Truck is Ford.

 

[houndman]

Hmmm,
Not considering premature of uneven wear of your tires? If they are
inflated too much over or under the rating you can mess up the even tire
tread wear. Under inflated tires can over heat. You know what it can
cause on prolonged high speed cruising. You don't drive on highways?
Under inflation can be dangerous. Too over inflated, you lose
control/handling. What's wrong with WRX? I have one in the family.
Kids drive Subaru, I am a Honda man. Truck is Ford.

when the factory Only gives One pressure rating for an empty or fully
loaded vehicle, to me it can only be right in one situation, or an
average. If 33psi is the right pressure for the front tires with 58%
of the weight on them, than 30psi can't be right for tires with 42% of
the weight. Fully loaded maybe.

For the streets I test drove the WRX on and even drive the 2,5i on,
and Maybe because of the newness of the suspension and seat, that
initially felt like the lumbar area was too stiff or protruded too
much, and damaged sensitive muscles, even my 2.5i Hopped over slight
irregularities in the streets, that was very uncomfortable. I am
probably more sensitive than most do to an injury, but don't enjoy
something that jolts me, that doesn't in other cars. All my cars have
had HD suspensions, since that's what I prefer. Now after some mileage
things are much more acceptable, even with slightly higher than
factory recommended tire pressures.

I don't think 24psi in the unloaded rear of an Impreza wagon is too
little. I run 20psi in a mid sized Chevy FWD car, though that has
oversized tires in the rear, and never put more than 25 in the rears
of any cars, and never had a problem with uneven tread wear, or
failures.

 

[Tony Hwang]

when the factory Only gives One pressure rating for an empty or fully
loaded vehicle, to me it can only be right in one situation, or an
average. If 33psi is the right pressure for the front tires with 58%
of the weight on them, than 30psi can't be right for tires with 42% of
the weight. Fully loaded maybe.

For the streets I test drove the WRX on and even drive the 2,5i on,
and Maybe because of the newness of the suspension and seat, that
initially felt like the lumbar area was too stiff or protruded too
much, and damaged sensitive muscles, even my 2.5i Hopped over slight
irregularities in the streets, that was very uncomfortable. I am
probably more sensitive than most do to an injury, but don't enjoy
something that jolts me, that doesn't in other cars. All my cars have
had HD suspensions, since that's what I prefer. Now after some mileage
things are much more acceptable, even with slightly higher than
factory recommended tire pressures.

I don't think 24psi in the unloaded rear of an Impreza wagon is too
little. I run 20psi in a mid sized Chevy FWD car, though that has
oversized tires in the rear, and never put more than 25 in the rears
of any cars, and never had a problem with uneven tread wear, or
failures.

Hi,
Manual shows typical cover all situation tire pressures. Can I make a
suggestion? with 20 psi pressure, go out to turn pike and cruise about
couple hundred miles and see what happens. Often see all those shredded
tire thread rubber pieces on the road? What do you think happened?
I always raise pressure ~5% when towing. Same with hypermiling.
All cars/trucks in my family has upgraded suspension. I like to drive
vehicle which gives feedback from the road. I am a driver not a vehicle
operator. Been at it over 50 years. Look at the tread evenness across
your tires. Do they all look even?

 

[houndman]

Hi,
Manual shows typical cover all situation tire pressures. Can I make a
suggestion? with 20 psi pressure, go out to turn pike and cruise about
couple hundred miles and see what happens. Often see all those shredded
tire thread rubber pieces on the road? What do you think happened?
I always raise pressure ~5% when towing. Same with hypermiling.
All cars/trucks in my family has upgraded suspension. I like to drive
vehicle which gives feedback from the road. I am a driver not a vehicle
operator. Been at it over 50 years. Look at the tread evenness across
your tires. Do they all look even?

one of the rear tires in my old car has a very slow leak from a brad
in the tread, that I haven't fixed, since it is mainly driven in a
city, but it has been down to 7psi after I drove it on the highway,
and it still is intact. Being oversized and on the rear of a FWD car,
it has to get really low before it looks low. Since I never had a tire
fail or uneven wear in my 50 yrs of driving, I guess I do something
right. Those oversized tires have some pretty big cracks in the
sidewall on the inboard sidewalls. Good thing I only see them when I
have the tires off. )) To me the outer rubber is mainly to protect the
fabric from abrasion, which it isn't going to get very easily on the
inner sidewall. I worry more about the smaller, recommended size front
tires for the car, because of the extra weight they have to carry. The
rears can probably carry double the weight they do.

 

[Rick Courtright]

it has been down to 7psi after I drove it on the highway,
and it still is intact. Being oversized and on the rear of a FWD car,
it has to get really low before it looks low. Since I never had a tire
fail or uneven wear in my 50 yrs of driving, I guess I do something
right.

Hi,

I'd suggest it's more likely Mr. Darwin just works slowly.

Rick

 

[suburboturbo]

Hi,
Manual shows typical cover all situation tire pressures. Can I make a
suggestion? with 20 psi pressure, go out to turn pike and cruise about
couple hundred miles and see what happens. Often see all those shredded
tire thread rubber pieces on the road? What do you think happened?
I always raise pressure ~5% when towing. Same with hypermiling.
All cars/trucks in my family has upgraded suspension. I like to drive
vehicle which gives feedback from the road. I am a driver not a vehicle
operator. Been at it over 50 years. Look at the tread evenness across
your tires. Do they all look even?- Hide quoted text -

- Show quoted text -

As long as you're within reasonable limits on the tire manufacturer's
spec, go with whatever's comfortable and provides the level of
responsiveness that your driving style demands. Vehicle
manufacturer's specs are often bogus. For example, I used to drive a
Suzuki Samurai, a vehicle with an ultra-short wheelbase, a pair of
solid axles and a rock hard truck suspension with zero compliance. To
appeal to the US market, Suzuki recommended 24 psi (may be off on the
nymber but sure it was low-mid 20's) to soften the ride. Of course,
the handling was awful. Consumer Reports aside (everyone remembers
the rollover "test" with the ouriggers that appeared on 60 Minutes,
but nobody seems to know that after a prolonged legal battle, CU was
forced to admit that they "never intended to imply that the Samurai
easily rolls over in routine driving conditions." With 35 psi, it
handled well and was very responsive. Not a Lotus, mind you, but out-
cornered any other SUV (actually transformed a pure "utility vehicle"
into a "sport utility vehicle". The ride was "somewhat" rough, to say
the least. Only time I used the factory spec was when driving in
sand, where it was unstoppable, just as it was in snow, mud, gravel,
etc. Okay, a little wordy, but just wanted to say that manufacturers
may specify less than optimum numbers for reasons that have nothing to
do with performance. By the way, that Samurai lasted 20 years,
130,000 miles and spent the last two years of its life as a tractor
hauling rocks and stumps through the woods clearing a hiking/biking
trail through my brother's mountain retreat. Never had a serious
problem with it; survived a rear-end collision with a dump truck that
lost its brakes, drove it from Nags Head to Lake Placid and on the
beach at Chappaquidick (no great fan of Ted Kennedy, but that bridge
he drove off would be trouble for a sober driver in broad daylight).
Best "cheap" new "car" I ever bought.

 

[JD]

Hi,

I'd suggest it's more likely Mr. Darwin just works slowly.

Rick

I agree. 7 PSI is damned close to where the bead will collapse.

 

[sarahs choice]

Hi,

I'd suggest it's more likely Mr. Darwin just works slowly.

Rick

too true!!!

 

[houndman]

too true!!!

Yea, Mr Darwin never met me. Guess it wasn't wise to not plug a
puncture sealing tire after pulling a roofing nail out, a few hrs
before a 420mi trip on the Interstate. It only lost 3psi in 4 hrs
before the trip.

Things like wet weather traction, and tire load cap are important to
me, not things that aren't a concern. My dad was Real old school, and
wouldn't park in a tire that had had a flat in any water. They Used to
think that a Tube Type Tire that the tube was patched, the cotton cord
in the carcass would rot, from water that got in an unplugged
puncture, and blow out. Didn't make any difference that tires were
tubeless at the time, and you plugged the carcass.