Car people: Question about tire pressure....

[KDOG]

The tires on my car (Kumho ECSTA) have a max pressure rating of 44PSI, so I put 40 in them. Is that still too much or is that good?

 

[ScottFern]

Thats fine.

 

[DurocShark]

I always fill them to the pressure listed in the vehicle manual when cold.

Note that the manual ALWAYS overrides the tire max spec UNLESS it exceeds the tire's max spec, in which case the tires are unsafe in that application.

 

[ViviTheMage]

weather matters

 

[tvbi]

Manual said 32 and 30 but I find that's too low, the ride is too soft and gas milage sucks.. I do 43 and 41 (low profile tires)

 

[SVT Cobra]

Depends on the weather.

 

[DurocShark]

Ok, let me qualify my statement by saying that it applies to stock sizes.

 

[Umberger]

Originally posted by: DurocShark
I always fill them to the pressure listed in the vehicle manual when cold.

Note that the manual ALWAYS overrides the tire max spec UNLESS it exceeds the tire's max spec, in which case the tires are unsafe in that application.

QFT.. this thread scares me.

 

[mcvickj]

Originally posted by: F22 Raptor
Depends on the weather.

I've heard this before Care to elaborate? Do you want your tires software for cold weather? Or is it the other way around?

 

[Heisenberg]

You should always inflate them to the pressure listed in the door jam of the vehicle or the owner's manual. The max pressure on the tire is just what the tire can withstand, not what it should normally be inflated to.

 

[thomsbrain]

Originally posted by: DurocShark
I always fill them to the pressure listed in the vehicle manual when cold.

Note that the manual ALWAYS overrides the tire max spec UNLESS it exceeds the tire's max spec, in which case the tires are unsafe in that application.

right, cause if you don't, the ENTIRE CAR WILL EXPLOOOOOOOODE!!!!!!!!!!!!!!!!!!!!

my car handles better and gets better mileage when the pressure is higher than recommended. yeah, it rides rougher, and yeah, that might take a bit of a toll on the suspension, but it's not any worse than aftermarket rims would be. you also decrease your risk of a blow-out because the tires don't get nearly as hot, especially under heavy loads. I know several retired Highway Patrol officers who have said they ALWAYS ran their tires higher than recommended. if you actually run the tires at the recommended pressures on my car, the tires compress noticeably, even without a load. i will trade a rougher ride for increased handling and mileage and decreased risk of a blow-out any day, thank you very much.

 

[thomsbrain]

Originally posted by: mcvickj

Originally posted by: F22 Raptor
Depends on the weather.

I've heard this before Care to elaborate? Do you want your tires software for cold weather? Or is it the other way around?

you would want them higher, because they will expand less in the cold air and on cold pavement, and because a smaller contact patch will give you increased wet traction. i can't speak for the effect on snow, though, since i've never played with pressures in the snow.

 

[giantpinkbunnyhead]

I usually keep my truck tires inflated a bit above what the mfr recommends. Helps mileage and also seems to help in the wintertime.

 

[Bateluer]

My max is listed on the tire as 35psi, I fill them to about 32psi.

 

[mercanucaribe]

Put in what the manual/sticker says. The tire's rating is meaningless.

 

[Vette73]

Do NOT put 40psi in a street tire. That is probable way to high.


You need to see what the car came with and also adjust for what and where you drive.

The nunbers on the car are COLD numbers. If you drive the car and check the pressure you will be to low. Also I have found that haveing about 2 psi more in the front helps the tires wear better.

And don;t forget. Temp's affect pressure. So if you put in 34psi in teh front today and the temps drop 10degrees, your 34 might be a 28 and be to low.

I use around 33psi front and 31rear.

 

[DurocShark]

Originally posted by: thomsbrain

Originally posted by: DurocShark
I always fill them to the pressure listed in the vehicle manual when cold.

Note that the manual ALWAYS overrides the tire max spec UNLESS it exceeds the tire's max spec, in which case the tires are unsafe in that application.

right, cause if you don't, the ENTIRE CAR WILL EXPLOOOOOOOODE!!!!!!!!!!!!!!!!!!!!

my car handles better and gets better mileage when the pressure is higher than recommended. yeah, it rides rougher, and yeah, that might take a bit of a toll on the suspension, but it's not any worse than aftermarket rims would be. you also decrease your risk of a blow-out because the tires don't get nearly as hot, especially under heavy loads. I know several retired Highway Patrol officers who have said they ALWAYS ran their tires higher than recommended. if you actually run the tires at the recommended pressures on my car, the tires compress noticeably, even without a load. i will trade a rougher ride for increased handling and mileage and decreased risk of a blow-out any day, thank you very much.

And most of us don't wish to risk the loss of dry pavement traction, the handling changes outside of the vehicle's design specifications, and prefer to avoid the accellerated wear on suspension components.

What you do is up to you. But the guys who design these things generally know WTF they're talking about when they provide a specification. After all, if it's wrong somebody could die.

 

[fbrdphreak]

Originally posted by: DurocShark

Originally posted by: thomsbrain

Originally posted by: DurocShark
I always fill them to the pressure listed in the vehicle manual when cold.

Note that the manual ALWAYS overrides the tire max spec UNLESS it exceeds the tire's max spec, in which case the tires are unsafe in that application.

right, cause if you don't, the ENTIRE CAR WILL EXPLOOOOOOOODE!!!!!!!!!!!!!!!!!!!!

my car handles better and gets better mileage when the pressure is higher than recommended. yeah, it rides rougher, and yeah, that might take a bit of a toll on the suspension, but it's not any worse than aftermarket rims would be. you also decrease your risk of a blow-out because the tires don't get nearly as hot, especially under heavy loads. I know several retired Highway Patrol officers who have said they ALWAYS ran their tires higher than recommended. if you actually run the tires at the recommended pressures on my car, the tires compress noticeably, even without a load. i will trade a rougher ride for increased handling and mileage and decreased risk of a blow-out any day, thank you very much.

And most of us don't wish to risk the loss of dry pavement traction, the handling changes outside of the vehicle's design specifications, and prefer to avoid the accellerated wear on suspension components.

What you do is up to you. But the guys who design these things generally know WTF they're talking about when they provide a specification. After all, if it's wrong somebody could die.

Bingo.

Tire pressures in the 40psi range decrease traction and increase potential of a blowout (more so if you hit pot holes & stuff, not just normal driving). Add air to your tires when cold to the manufacturer specs + a few PSI. More than a few PSI above manufacturer ratings puts you at risk for trouble. You're pretty significantly altering the vehicle's handling and in an emergency situation, the vehicle may not respond as it should.

 

[thirdeye]

Like others have said 40 psi is definitely too much for normaly daily driving. I'll put almost 38 in before an auto-x but usually drop it down till I hit a sweet spot, but never go higher. Generally 32-35 is recommended for MOST tires.

 

[JoLLyRoGer]

I run right at the recommended pressure. You get the best combination of tread-wear, handling, and gas mileage if you go by the spec.

There are special situations where I'll run low if I need a little bit of extra "bite" (like off road)

 

[DurocShark]

Throwing out specific PSI's means nothing. Each vehicle has its own requirements.

My VW Bus uses D rated tires (commercial) in the 40's. My Volvo 244GL uses passenger tires, but ones with a higher load rating, and 38-42 are the recommended inflations.

These two vehicles mean I don't get to buy the $25 specials.

 

[OrganizedChaos]

manufacturer specs 28 psi all around on 235/75/15 radials.

i put 28.5-31 in the front radials. max tire can handle is 35
i put 33-35 in the rear bias plies. max tire can handle is 44

in the winter i'll probably adjust to 30 all around.

 

[FoBoT]

the book and the label on the door tell you what pressure to do

 

[Captante]

I keep the same ration from front to rear tires listed in the cars specifications, but I always run my tires a few lbs higher then factory air pressure.

 

[jagec]

about 32/32 on my car (door jam is 30 IIRC), and 38/41 on the bike (spec is 33/41)