Correct Tire Pressure ?

Hello,

Have a 2009 Buick LaCrosse.
Tires on it are Nokian WRG2 225/60R16 98H

Folks at the dealership checked tire pressures during an oil change,
and have now
made them all 35 psi (when cold).

Have to admit that the car seems to handle a bit better with the
higher pressures.

Used to be around 31 psi when cold and just starting out.

Tech Support at Nokian says to use what is on the car door sticker.
They would not suggest any p which is a bit surprising as I thought
the 'correct' pressure was probably
more specific tire type determined, than what Buick would suggest.

Anyway, it's now 35 psi when cold.
Goes up to about 38 after driving.

Car sticker says to set at 30 psi

Think what I have now (35/38 psi) is "safe" for summer driving ?
Would hate to have a blowout due to higher pressures. 38 psi sounds
quite high (to me). Is it ?
Safety aspects are really important to me.

Any thoughts would be most appreciated.

Thanks,
Bob

If the tires are wearing fine with 31 lbs, put them back to 31. The
oppisite is true, air pressure to low, (25 or under), will cause a
blow out. You would be surprised at the how much air you can put in a
tire before it blows. Air pressure to high will cause the center of
the tire tread to wear faster. Air pressure to low will cause both
outer edges of a tire tread to wear faster.

Robert11 > wrote:
>Tech Support at Nokian says to use what is on the car door sticker.
>They would not suggest any p which is a bit surprising as I thought
>the 'correct' pressure was probably
>more specific tire type determined, than what Buick would suggest.
>
>Anyway, it's now 35 psi when cold.
>Goes up to about 38 after driving.
>
>Car sticker says to set at 30 psi

The question is what is the contact surface area of the tire when you make
a turn? How much tread is contacting the road?

Mark on the tire with a thick white china marker, then drive on the road
and make a few tight turns. Do you get nice even wear across the surface
of the tire? If so the pressure is good.

>Think what I have now (35/38 psi) is "safe" for summer driving ?
>Would hate to have a blowout due to higher pressures. 38 psi sounds
>quite high (to me). Is it ?

You won't have a blowout because the pressure is too high... it's still
probably way below the maximum rating on the side of the tire.

But you MIGHT have an accident because your handling is poorer than it
should be, or because you skid when you wouldn't have skidded if you'd had
more tire grip.

Then again, you might ALSO have far better handling and more contact area
than you would with the lower pressure.

>Safety aspects are really important to me.
>
>Any thoughts would be most appreciated.

Don't guess, measure.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Apr 18, 12:38*pm, Robert11 > wrote:
> Hello,
>
> Have a 2009 Buick LaCrosse.
> Tires on it are Nokian WRG2 * 225/60R16 * *98H
>
> Folks at the dealership checked tire pressures during an oil change,
> and have now
> made them all 35 psi (when cold).
>
> Have to admit that the car seems to handle a bit better with the
> higher pressures.
>
> Used to be around 31 psi when cold and just starting out.
>
> Tech Support at Nokian says to use what is on the car door sticker.
> They would not suggest any p which is a bit surprising as I thought
> the 'correct' pressure was probably
> more specific tire type determined, than what Buick would suggest.
>
> Anyway, it's now 35 psi when cold.
> Goes up to about 38 after driving.
>
> Car sticker says to set at 30 psi
>
> Think what I have now (35/38 psi) is "safe" for summer driving ?
> Would hate to have a blowout due to higher pressures. *38 psi sounds
> quite high (to me). *Is it ?
> Safety aspects are really important to me.
>
> Any thoughts would be most appreciated.
>
> Thanks,
> Bob

Chalk 'em and find out.

http://www.google.com/search?q=chalk+tire+pressure

nate

The "correct" tire pressure according to almost all tire companies and car
companies is the one provided by the vehicle manufacturer, assuming you are
using the OE tire size. If you have changed the tire size to one that was
not an option for your car, then you'll need to experiment. I'd never go
lower than the pressure recommended by the car manufacurer. The pressure
listed on the tire sidewall is the maximum pressure allowed for that tire,
not the correct one for the car. Idiots at tire stores often inflate tires
to the max pressure listed on the side walls. This is not really a big deal
with regualr P series tires since they mostly have a 35 or 36 psi maximum
pressure listed on the sidewalls and most cars these days recommend
something in the 27 to 35 psi range. You can get in trouble if you ahve LT
tires or P series extra load tires. These can have maximum pressures listed
on the sidewalls of 45 psi or greater. Try driving something that was
intended to use 35 psi with the tires inflated to 45....not fun.

I see others mention the chalk test. I suppose if you rub the chalk all over
the tire and drive it like you normally do, it might show you something. A
better modern test would be to use a contact thermometer to check the
temperature across the width of the tires after a "normal" period of
driving. You'd like to see a consitent temperature from one edge to the
other. But if you only do short trips, seems like you might never actually
reach steady state on the tire temperature.

Best bet is to go with the vehcile manufactuer's recommendation, and if you
like the firmer feel, an extra pound or three won't hurt anything (just
monitor the tires for excessive wear in the center).

Ed

"Robert11" > wrote in message
...
> Hello,
>
> Have a 2009 Buick LaCrosse.
> Tires on it are Nokian WRG2 225/60R16 98H
>
> Folks at the dealership checked tire pressures during an oil change,
> and have now
> made them all 35 psi (when cold).
>
> Have to admit that the car seems to handle a bit better with the
> higher pressures.
>
> Used to be around 31 psi when cold and just starting out.
>
> Tech Support at Nokian says to use what is on the car door sticker.
> They would not suggest any p which is a bit surprising as I thought
> the 'correct' pressure was probably
> more specific tire type determined, than what Buick would suggest.
>
> Anyway, it's now 35 psi when cold.
> Goes up to about 38 after driving.
>
> Car sticker says to set at 30 psi
>
> Think what I have now (35/38 psi) is "safe" for summer driving ?
> Would hate to have a blowout due to higher pressures. 38 psi sounds
> quite high (to me). Is it ?
> Safety aspects are really important to me.
>
> Any thoughts would be most appreciated.
>
> Thanks,
> Bob

On Apr 18, 7:38*pm, Robert11 > wrote:
> Hello,
>
> Have a 2009 Buick LaCrosse.
> Tires on it are Nokian WRG2 * 225/60R16 * *98H
>
> Folks at the dealership checked tire pressures during an oil change,
> and have now
> made them all 35 psi (when cold).
>
> Have to admit that the car seems to handle a bit better with the
> higher pressures.
>
> Used to be around 31 psi when cold and just starting out.
>
> Tech Support at Nokian says to use what is on the car door sticker.
> They would not suggest any p which is a bit surprising as I thought
> the 'correct' pressure was probably
> more specific tire type determined, than what Buick would suggest.
>

If tirerack tech articles are to be trusted at 35 the hydroplaning
resistance
is typically better than at 30psi. Not an issue if you crawl in
torrential rain
but is probably more important with asymmetric tread pattern
tire such as WRG2 than with symmetrical tires that are often quite
good at getting water and slush out at freeway speeds.

On Apr 18, 12:38*pm, Robert11 > wrote:
>
> Tech Support at Nokian says to use what is on the car door sticker.
> They would not suggest any p which is a bit surprising as I thought
> the 'correct' pressure was probably
> more specific tire type determined, than what Buick would suggest.

Tire size and recommended pressures are spec'd by vehicle
manufacturers.

> 38 psi sounds
> quite high (to me). *Is it ?

No, it's a little on the high side, shouldn't be a problem for a
reasonable motorist.
-----

- gpsman

On Wed, 18 Apr 2012 09:38:17 -0700 (PDT), Robert11
> wrote:

>Have a 2009 Buick LaCrosse.

>Car sticker says to set at 30 psi

My 2004 Buick Century (bought new) also says to set it at 30 psi all
around. That seemed a little low to me too. I have compromised at 32
psi all these years. Probably my imagination but it seems to make the
ride a bit harder. Perhaps Buick specifies 30 psi to give this low end
Buick a softer ride? It currently has 22K miles on it (don't use it
much) and the tires still look new, no noticeable wear patterns. Now I
have to decide when to replace them because of old age (now 8 years
old). I've read different opinions on the matter but the consensus
seems to be 10 years. Opinions here?

AJL > wrote:
> On Wed, 18 Apr 2012 09:38:17 -0700 (PDT), Robert11
> > wrote:
>
>> Have a 2009 Buick LaCrosse.
>
>> Car sticker says to set at 30 psi
>
> My 2004 Buick Century (bought new) also says to set it at 30 psi all
> around. That seemed a little low to me too. I have compromised at 32
> psi all these years. Probably my imagination but it seems to make the
> ride a bit harder. Perhaps Buick specifies 30 psi to give this low end
> Buick a softer ride? It currently has 22K miles on it (don't use it
> much) and the tires still look new, no noticeable wear patterns. Now I
> have to decide when to replace them because of old age (now 8 years
> old). I've read different opinions on the matter but the consensus
> seems to be 10 years. Opinions here?

I never got that much milage from tires. If kept indoors, they should be
good. I had one set on a car for longer, but you could start to feel the
dryness, and some cracking. Cracking occurred with me on a set of
performance michelins in less than two years. Did a lot of armor all, which
I suspect was the major reason, aside from being in the outdoors, in the
desert. I think you have to worry about the inner layers which you can't
see.

Greg

gregz > wrote:
> AJL > wrote:
>> On Wed, 18 Apr 2012 09:38:17 -0700 (PDT), Robert11
>> > wrote:
>>
>>> Have a 2009 Buick LaCrosse.
>>
>>> Car sticker says to set at 30 psi
>>
>> My 2004 Buick Century (bought new) also says to set it at 30 psi all
>> around. That seemed a little low to me too. I have compromised at 32
>> psi all these years. Probably my imagination but it seems to make the
>> ride a bit harder. Perhaps Buick specifies 30 psi to give this low end
>> Buick a softer ride? It currently has 22K miles on it (don't use it
>> much) and the tires still look new, no noticeable wear patterns. Now I
>> have to decide when to replace them because of old age (now 8 years
>> old). I've read different opinions on the matter but the consensus
>> seems to be 10 years. Opinions here?
>
> I never got that much milage from tires. If kept indoors, they should be
> good. I had one set on a car for longer, but you could start to feel the
> dryness, and some cracking. Cracking occurred with me on a set of
> performance michelins in less than two years. Did a lot of armor all, which
> I suspect was the major reason, aside from being in the outdoors, in the
> desert. I think you have to worry about the inner layers which you can't
> see.
>
> Greg

I see those same michelins on ferraris, resurrected from storage, they look
fine on tv. Michelin XWX. I think I got maybe 10k at most. Very sticky
tire, but not linear breakaway.

Greg