Tire Pressures

Hello,

Live in New England.

Had a new set of 4 all weather tires put on recently; Nokian's WR G2. Car is a 2009 Buick LaCrosse

Asked the tire shop to set the pressures at 30 psi, as that is what the car sticker by the door says.

He set it at 33 psi, and I notice after driving a while that it goes up to 35 psi per the TPMS readout.

The folks at the tire store said emphatically that they always set the pressures "a bit" higher as it prolongs tire life, etc.

I think that I read somewhere many years ago, also, that this was a good idea.

Question: even though car's sticker says 30 psi, is having it set to 33 psi when cold, going to 35 when warmed up "safe" ?

Good idea ?

Thanks, Bob

Reply to
Bob
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Depends on the car, really. But so long as the cold pressure is not higher than the max pressure on the sidewall it's not going to cause catastrophic tire failure. Hot pressure is more or less irrelevant. What is important is how the car rides and handles. I've found that on my company car (Chevy Impala) running the tires at the recommended pressure results in a floaty ride and imprecise handling, and also fast wear on the outside edges of the front tires, so in that car I do run the pressure a little higher than spec. But really that just requires some experimentation to determine whether that's the case for your car or not. (I suspect that the Lacrosse is basically the same chassis, yes?)

nate

Reply to
Nate Nagel

Bob wrote in news:j6pl1r$7gc$ snipped-for-privacy@dont-email.me:

It's perfectly /safe/. But is it something that will be liked by your government-mandated tire-pressure-monitoring system? That's another story.

If your TPMS eventually complains, take the pressures back down to 30. If the TPMS light stays off, leave the pressures where they are.

I'm suspecting Buick has specified the slightly-lower pressure simply to help improve the ride.

Reply to
Tegger

I usually cold set the fronts at 32-33 and rears at 31-32. Auto manufacturers like the mushy soft ride of 26-30. Unfortunately that makes for minimum control and is prone to roll overs, as Ford found out the hard way a few years ago.

Reply to
Paul in Houston TX

#1 Soft tries cause roll overs.

Soft tires can also cause excessive heat buld up which may lead to tire failure. I follow the sidewall max pressure less 10 percent. If it says 44psi I make the cold 40.

Reply to
me at

Drive through some mud, or put some chalk on the tires and drive around the block making sure to do some tight turns.

Find out what the actual contact area of the tire is.

If the tires are not the same profile as the ones that came with the car, the optimal pressure may not be the same as the recommendation.

If you overinflate the tires, you will have reduced contact area on the edges, and so your tires will wear out faster in the center. This will also affect your handling adversely. But then again, underinflation is just as bad.

Unless you actually look at the footprint you won't know.

--scott

Reply to
Scott Dorsey

Yes. If you underinflate, you'll somehow wear the tires out faster at the edges. I've certainly done that.

The goal is to have the tires flat on the bottom, so the whole width of the tire is evenly pressing against the road.

AIUI, if you take the area of the tire that touches the road, multiply it by the tire pressure, add that value for all 4 tires together, and the sum will be the weight of the car and its contents.

There is also the fact that high tire pressure increases mileage, but I have no idea how much. I don't know if low pressure really makes a softer ride or not, but smaller wheels with the same diameter tire, thus a wider side wall., will make a softer ride. 16" or 17" wheels with a narrow side wall will make a harder ride.

Reply to
micky

And as someoen said, it's the cold pressure that all the numbers are given for. It's assumed that the tire will warm up and the pressure will increase. But they don't want people on the hood measuring tire pressure while the car is moving.

Reply to
micky

____________________________ Well, except for the fact that THEY DIDN'T LISTEN TO YOU, THE CUSTOMER'S INSTRUCTIONS!!! (Read my tire pressure drama at:

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247d449c# ) Technically nothing wrong with that, except that it more frequently triggers your TPMS indicator. As a general rule I ride 2psi higher than the door/hood/trunk/wherever decal, unless that puts me over the max. inflation pressure shown on the tire itself. I.E.: My last 3 cars have all specified 30psi cold, hence I inflate 32psi cold.

Irrelevant to this discussion, but there is out there in WWW Land a site that suggests you inflate your tires to 36-37psi cold IN WINTER if you live north of 45 degrees north, and closer to the door sticker come spring & summer, implying that 36psi in winter = IE 30psi in summer. Whaddever my brain hurts!!

-CC

Reply to
ChrisCoaster

Reely? How's that work? For which cars is it safe/not safe?

What if you drive on it, say, at a "perfectly safe" 80 mph, and hit a wicked pothole?

Good to know tread wear isn't important...

That doesn't make any sense. Far more likely you brake while cornering, too hard.

You should shut the f*ck up about shit you know nothing about. -----

- gpsman

Reply to
gpsman

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