Max Tire Pressure?
- Thread starter jake26
- Start date
pattenp
Well-known member
If you are using the manufacturer suggested tire size then you use the pressure that is listed on the label in the door jamb of the car..
Is this your tire size? P195/70R14, if so then 30psi front and rear.
Is this your tire size? P195/70R14, if so then 30psi front and rear.
Last edited:
jayoldschool
Well-known member
It will say on the sticker on the door what the factory suggests, but you will be fine at 35.
pattenp
Well-known member
Just don't use 35 psi as a guess. Use the pressure suggested for the tire size. Running the tire at over pressure or under pressure will cause the tread to wear unevenly.
Not to mention it won't have the correct contact patch with the road. Sticker in the door jam or check the owner's manual for the correct tire size and pressure. The only time I would ever inflate a tire based on what is written on the side wall, is on a trailer.
henrysgarage
Well-known member
My 09 Impala wears all the 4 tires on both sides of the tire so I now keep the tires 2 psi over the door sticker. Other Impala owners have noted the same issue. I read somewhere that you take the car's weight and divide by 100 and that will give you a starting point, plus add 2 lbs on the engine end. How this compares to the sticker I do not know, I guess you would have to weigh the car in the normal loaded situation and do the math and see how close it is to the door sticker.
In the tire/ wheel seminar we took they said to never use the max tire pressure unless the tire is carrying the max load.
In the tire/ wheel seminar we took they said to never use the max tire pressure unless the tire is carrying the max load.
mmhouse
Well-known member
My dad always ran 32psi cold in his tires - this was in the 50's and 60's. I run whatever the door sticker calls for but I have to chuckle every time I look because it's always 32psi plus or minus a couple of pounds.
I think his system was easier and probably just about as good.
I think his system was easier and probably just about as good.
PinkLinc
Well-known member
I've been wondering the same thing but with a bit of a twist. If the car originally came with run-flats, but I no longer use run-flats, does the recommended tire pressure on the door sticker become irrelevant due to the added stiffness of the run-flat sidewalls?
2002 MINI S. The wheels in question are the original OEM wheels and the tires are the same size as original.
2002 MINI S. The wheels in question are the original OEM wheels and the tires are the same size as original.
SGKent
Banned
run the door sticker and measure the tread depth occasionally. Adjust accordingly. Our Acura RL is dead on when cold using the sticker but the Sable wagon is under pressure based on wear. Sometimes a manufacturer will lower the pressure to make it ride smoother or understeer but that won't give you best wear and traction. What you usually want is maximum contact area with evenly distributed weight.
Big-Foot
Well-known member
I run 5 psi under the max inflation pressure on the sidewall. The 5 psi delta is to cover the pressure increase as the tires get hot in use.
On my race cars, we use 8 psi as the delta from max race pressure when the cars go out cold, but we are punishing those tires and build up a lot of heat.
I do not follow the auto manufacturers inflation pressures due to a number of different reasons but a few would be;
1) Tire manufactures know their products better that the auto mfgr
2) The auto mfgr is going to give you the best pressure for a smooth ride, but that is rarely the best pressure for the tire for performance, mileage, etc.
3) Look up Ford Explorer and Michelin Tires - you won't need to know what 4, 5 and 6 might be...
On my race cars, we use 8 psi as the delta from max race pressure when the cars go out cold, but we are punishing those tires and build up a lot of heat.
I do not follow the auto manufacturers inflation pressures due to a number of different reasons but a few would be;
1) Tire manufactures know their products better that the auto mfgr
2) The auto mfgr is going to give you the best pressure for a smooth ride, but that is rarely the best pressure for the tire for performance, mileage, etc.
3) Look up Ford Explorer and Michelin Tires - you won't need to know what 4, 5 and 6 might be...
klarmie
Well-known member
FYI, the maker of the tire does NOT know what vehicle you are going to install their tire on when they make the tire. Therefore the max psi on the sidewall is just for the tire at maximum load. The car maker sets the psi for best all around drivability, note that doesnt always mean best wear. It means a trade off between wear, mileage and handling. Your actual experience may vary, and you may need to adjust your tire pressure to suit your driving style/habits. 
dirttracker18
Well-known member
Bad advice and some misunderstanding.
The inflation numbers on the sidewall of a tire are MAX inflation pressure IF the tire is carrying its MAX load, which it rarely is.
The tire manufacturers can only " know best " the max load and pressure for that load.
If you want to get very specific ( I do for races requiring street tires) you could weight your car at each wheel and use the load and pressure ratings on the tires to come up with an exact pressure for that specific weight.
However, just use the sticker on the door jamb.
Once again the sidewall pressure is the MAX pressure for the MAX weight load of that tire!
Tire pressures, youo can file this question right with air line materials and wall materials.
I run my at 2-3 under the tires max spec. In the winter, I'll put them right on the max.
I run my at 2-3 under the tires max spec. In the winter, I'll put them right on the max.
mmhouse
Well-known member
I agree. The max pressure specified on the sidewall has nothing to do with what you should be running for best comfort, handling or treadwear. Start with the door sticker and watch treadwear as suggested earlier.
Lotek
Well-known member
I've been a mechanic for years, but until I started autocrossing, I never understood how much of a difference even 2 pounds make, it can be the difference between controllable oversteer and spinning out. Unless you have a really good reason, stick with the car mfg recommendation. My truck tires have a max pressure of 80psi on the sidewall, fronts are supposed to be set at 60, I have seen people running everything from 30 to 80, with the attendant wear and/or ride issues. The tire guy who puts 35psi in everything is either lazy or...
I run the pressure I like for ride quality/suspension feel. It typically runs between 25-32 for passenger cars. An exception would be the rear tires on my Camaro I run at 20psi so they squish more upon acceleration and spin less. I like 22psi on the fronts as it softens the ride over bumps but gives an extremely numb turn in feel so I settle on 25/26 as a happy medium. On the old ladies SUV I will run 30 across the board, and for some FWD daily driver sedans I like 28 F and 32 R and this helps soften the ride with the extra weight over the front wheels. The only time I have seen abnormal tire wear was on the Camaro rears wear I'm often at 18/20 depending on tire temp.