Confused by proper tire pressures

[tenplay]

The plate on the door panel of my 2004 Forester recommends tire
pressures of 29 (front) 28 (back) with a light load and 29 (F) and 36
(B) with a full load. Yet I notice that, when mechanics service my car,
they usually put 32 lbs in all 4 tires. I am driving tomorrow on the
Interstate over the mountains from Olympia, WA, down to Oakland, CA,
with my son and our luggage. The I-5 could be slick. We will be
carrying chains just in case. I left the front tires at 32 and inflated
the back tires to 34. Does that sound about right? Somehow 29 seems
low. And I read somewhere that underinflated tires are bad for the
suspension and tires. Thanks for any advice.

 

[Carl 1 Lucky Texan]

The plate on the door panel of my 2004 Forester recommends tire
pressures of 29 (front) 28 (back) with a light load and 29 (F) and 36
(B) with a full load. Yet I notice that, when mechanics service my car,
they usually put 32 lbs in all 4 tires. I am driving tomorrow on the
Interstate over the mountains from Olympia, WA, down to Oakland, CA,
with my son and our luggage. The I-5 could be slick. We will be
carrying chains just in case. I left the front tires at 32 and inflated
the back tires to 34. Does that sound about right? Somehow 29 seems
low. And I read somewhere that underinflated tires are bad for the
suspension and tires. Thanks for any advice.

I think your sense of this is pretty good. Generally, I add 5-10% to
the recommended pressures, for 'normal' daily driving, for 2 reasons,
the car handles better and the pressure is sometimes a little low (often
just one odd tire???) the next time I check pressures - so the wear
probably averages out. And I always add a little more pressure for
extended highway travel with luggage and/or passengers - I suppose it
helps reduce heat in the tires as well as distribute wear and help with
handling.
Oh, but you should never use more pressure than that listed on the
sidewall as 'max' and pressures should ideally be tested on a 'cold' tire.

Carl

 

[Oscar_Lives]

The plate on the door panel of my 2004 Forester recommends tire pressures
of 29 (front) 28 (back) with a light load and 29 (F) and 36 (B) with a
full load. Yet I notice that, when mechanics service my car, they usually
put 32 lbs in all 4 tires. I am driving tomorrow on the Interstate over
the mountains from Olympia, WA, down to Oakland, CA, with my son and our
luggage. The I-5 could be slick. We will be carrying chains just in
case. I left the front tires at 32 and inflated the back tires to 34.
Does that sound about right? Somehow 29 seems low. And I read somewhere
that underinflated tires are bad for the suspension and tires. Thanks for
any advice.

Your mechanic is an idiot.

Inflate the tires to factory specifications when they are at the proper
ambient temperature.

 

[davesixtythree]

I alway check tyre pressure first thing in the morning. I follow the
door as the vehicle rollover and emergancy handling tests are done
with this pressure in mind. I do however well remember the Firestone
low pressure issues on the Explorer.

 

[JohnO]

I am driving tomorrow on the
Interstate over the mountains from Olympia, WA, down to Oakland, CA,
with my son and our luggage. The I-5 could be slick. We will be
carrying chains just in case.

You're carrying a basic emergency kit too, right?

Enjoy the trip, I wish our trips were as scenic here in the midwest.

-John O

 

[Frank]

The plate on the door panel of my 2004 Forester recommends tire
pressures of 29 (front) 28 (back) with a light load and 29 (F) and 36
(B) with a full load. Yet I notice that, when mechanics service my car,
they usually put 32 lbs in all 4 tires. I am driving tomorrow on the
Interstate over the mountains from Olympia, WA, down to Oakland, CA,
with my son and our luggage. The I-5 could be slick. We will be
carrying chains just in case. I left the front tires at 32 and inflated
the back tires to 34. Does that sound about right? Somehow 29 seems
low. And I read somewhere that underinflated tires are bad for the
suspension and tires. Thanks for any advice.

I just checked my '03 Forester's yesterday and put in 30 psi all
around.
Funny thing was when I got car and had over 3,000 miles on it, I
discovered tires were all 40 psi. I had taken to dealer for first time
oil change and complained and had him set to standard. Dealer claimed
that care were shipped at higher pressure to avoid having to reinflate
standing in lots. Ride is smoother at lower pressure but the high
pressure excursion did not harm tires and my mileage was up.

Probably a good idea to set pressure a little above specs since tires
are going to lose air anyway.

Frank

 

[Mickey]

Your mechanic is an idiot.

Inflate the tires to factory specifications when they are at the proper
ambient temperature.

Don't know if I'd put it that way but the mechanic doesn't
know how to properly inflate tires.

How much pressure you should run depend upon how much load
they are carrying. Lightly loaded the front of your car
will be the heavier end and should have higher pressure than
the rear. As car is loaded a larger % of the load is
carried by the rear of the car and ratio of front to rear
pressure will change.

What you need to do is weigh your car, each axle separately
and weigh with load that is typ for everyday driving. Next
weigh the car loaded as closely as you can to represent how
it will be loaded on your trip. Next refer to a load
inflation chart for your tires and inflate according to the
weight the tires will be carrying.

If for some reason you won't or can't do it the proper way,
use the chart on the car.

Mickey

 

[Jim Stewart]

The plate on the door panel of my 2004 Forester recommends tire
pressures of 29 (front) 28 (back) with a light load and 29 (F) and 36
(B) with a full load. Yet I notice that, when mechanics service my car,
they usually put 32 lbs in all 4 tires. I am driving tomorrow on the
Interstate over the mountains from Olympia, WA, down to Oakland, CA,
with my son and our luggage. The I-5 could be slick. We will be
carrying chains just in case. I left the front tires at 32 and inflated
the back tires to 34. Does that sound about right? Somehow 29 seems
low. And I read somewhere that underinflated tires are bad for the
suspension and tires. Thanks for any advice.

I found 32 all around to be a good compromise,
at least on an Outback. Generally you like to
have the fronts a little higher than the rears
because of the engine/transmission weight. About
the best I've found is 34 front and 32 rear.

 

[Frank]

Mickey wrote:
pressure will change.

What you need to do is weigh your car, each axle separately
and weigh with load that is typ for everyday driving. Next
weigh the car loaded as closely as you can to represent how
it will be loaded on your trip. Next refer to a load
inflation chart for your tires and inflate according to the
weight the tires will be carrying.

If for some reason you won't or can't do it the proper way,
use the chart on the car.

Mickey

My wife refuses to let me know her weight. Is it safe to drive her
around in my Forester or should she drive separately?
Frank

 

[bigjim]

32 all around works for me

I alway check tyre pressure first thing in the morning. I follow the
door as the vehicle rollover and emergancy handling tests are done
with this pressure in mind. I do however well remember the Firestone
low pressure issues on the Explorer.

 

[Trlather]

Follow tire pressure placard; an extra 2 or 3 psi is alright----if your
Forester is running around at 40 psi somebody did a half ass PDI on the
car; they are shipped overinflated from factory, "parking lot bleed
down" is BS, tire pressures are supposed to be set at PDI

 

[Edward Hayes]

Your 32/34 is what I run mine at when I expect to be loaded and 32/30
normally.

 

[Guest]

My wife refuses to let me know her weight. Is it safe to drive her
around in my Forester or should she drive separately?

In that case she needs to walk!

 

[Oscar_Lives]

She doesn't weigh that much. I can tell by her favorite: "reverse cowgirl"
that she isn't much over 125 lbs.

She might want to get that little mole looked at, however...

Merry Christmas!