I went out to check/adjust the tire pressure on my 1997 Saturn wagon today. The car has 4 new Sumitomo HTR A/S P01 tires. I checked the sidewall and found that the max pressure for these tires is 51 PSI. The manufacture recommended pressure on the door tag is 32 PSI for the front and 28 PSI for the rear. I also checked the tires on our “new” 2010 Pontiac Vibe as well. The max pressure listed on the sidewalls for the Goodyear tires on that is also 51 PSI but manufacture recommended pressure on the door tag 32 PSI. Which should I be using or should I just split the difference?
The max pressure on the sidewall is just what the tire is designed for in terms of a max. Its something that you can’t safely exceed.
You follow what is on the car’s tag.
Follow the label on the door, using a good gauge first thing in the morning. The tire value is a ‘do not exceed’ value, not a recommendation.
The information on the door tag is meant to provide the best balance in handling and ride. I usually add about 2 lbs to the recommended pressure to gain a little better fuel mileage. I don’t notice any difference except a slightly firmer ride, which I don’t mind. I definitely wouldn’t use the max pressure on the sidewall as a guide to what you should inflate them to.
You should only use what is on the Door…Never use the max pressure on the tire sidewall. If you looked closer you would have also noticed a weight. So it probably said 51 PSI @ 2000lbs. So you’d want to put the tire at 51 PSI if your vehicle weighed 8000lbs (2000 x 4).
I usually set my tires a couple of lbs over the stated pressure in the door jam. But NEVER EVER anywhere close to the MAX tire pressure.
As cigroller stated, the pressure listed on the tire’s sidewall is the maximum pressure to which the tire can be inflated. Maximum does not equate to desirable. For instance, if your doctor told you that he did not want to see your blood pressure at anything over…let’s say…140/90, that does not mean that your doctor considers 140/90 to be a healthy blood pressure.
The same size of tire may be used on many different makes and models of cars, with varying weight distribution and different handling characteristics. The manufacturer of the car has done extensive testing to determine a desirable tire pressure for each model, and that is what is listed on the driver’s door jamb or in the Owner’s Manual. The vehicle manufacturer’s recommended pressure should be used, although it is permissible to use slightly higher pressures.
Personally, I tend to use the car mfr’s recommended pressure as a guide, and then I usually inflate my tires to ~3 or 4 lbs more, in the interest of slightly better handling and slightly better gas mileage. Of course, you do need to preserve the front/rear bias stated by the mfr, so in the case of your Saturn, you might try 35 psi front and 31 psi in the rear.
In any event, do NOT inflate your tires to 51 psi or anthing even close to that pressure.
If you do, you will experience poor tire grip in wet weather, a rock hard ride that can damage ball joints and other front-end components, and greatly increased tread wear in the center section of the tread.
I’d likely go 32 all around. Never go to the max. listed on the sidewall. I will repeat texases advice to use a good gage.
There’s actually one kind of instance when you should go to the max on the tire sidewall. Its when the max on the sidewall equals the vehicle recommendation on the placard. Its not common but I had this situation on the last set of tire on my van. The tire max was 35 & the van is supposed to ride at 35 all around.
This drove me absolutely nuts, and had me obsessing about the tire pressure. I did not choose this set of tires and was thrilled to get rid of them when I finally did. (I double checked that the new ones went at least over 40psi cold. I think they’re now 44psi)
Yes, Aaron, door tag on each vehicle.
Remember , those tires could be on any vehicle. They can’t know when the make the tires so they state merely the maximum psi.
Using that sidewall information is how one can tell if the tires chosen are acually too light duty for the vehicle they’re on.
You used the words “max” and “recommended”. These are different.
On the Saturn you should use 32 PSI for the front and 28 PSI for the rear.
On the Pontiac you should use 32 PSI all around.
Thanks, that is what I thought ( and did). It just so happens that I’ve just never had tires on any car where the max sidewall pressure and the pressure recommended by the manufacture were not the same.
Thanks, that is what I thought ( and did). It just so happens that I’ve just never had tires on any car where the max sidewall pressure and the pressure recommended by the manufacture were not the same.
I’ve been owning cars/trucks for 40 years…and I’ve NEVER seen them where the max sidewell pressure is the same as the manufacturer recommended pressure…NEVER EVER…
So what, then is the sidewall pressure number if it is not ever used on light vehicles? Until I know better, I use it as a max pressure to not exceed when installing a tire on a rim. If adequate tire installing lube such as RuGlyde or a dilute soap solution is used, normally it is easy to set the beads on the rim long before the sidewall max pressure is approached.
I agree with Mike.
If the cars previously owned by the OP had tires whose sidewall displayed the same maximum pressures that are listed as the recommended pressure on the car’s doorjamb, the only possible explanation is that the tires were seriously under-sized for the car.
However, I find it hard to believe that every one of his cars came with seriously under-sized tires. As a result, I believe that the OP’s recollection is…wrong.
Well, as I noted above I just had matching numbers on my van. This is an Olds Silhouette. The tires were the right rating & size for the van - Bridgestones, so not an off-brand or something. They just happen to have a max cold rating of 35psi - which many passenger tires do. So I don’t think it would be completely impossible that the OP has frequently had 35psi max tires + a car spec of 32psi. That probably wouldn’t raise many questions.
Wha Who, you clearly understand the correct use of the sidewall pressure. Popping a bead on is an excellent example of where it can be used. But then, as you know, the tire should be reduced to the car’s specified pressure.
AaarontheCop, you should never pressurize tires to the maximum pressure specified on the tire sidewall. I believe your perception that all your cars have had sidewall pressure ratings that were the same as the car manufacturer’s specified ratings for the tires is due to a past misunderstanding of what these pressures mean. No car manufacturer specifies tires that way. The maximum safe pressure rating on the tires is the pressure at which the tires become in danger of catastrophic failure (blowing out) in use.
Always refer to your owner’s manual or your doorjam for the proper pressure for the vehicle.
I know this thread is about max psi
- but -
The only time I’ve ever ‘‘split the difference’’ twix the two was on my 91 & 92 Explorers. ( his & hers )
Y’know, the ones with the huge Firestone tire recall. I could not believe my eyes that the door plate said twenty-something psi !
So, guess what ?
I never aired them that rediculously low ( I used 32psi )
– AND –
I never ever had a problem with those tires.
they were the best combination of truck and tires I’ve ever owned. The most useable and versitile vehicles among all the 4x4s I’ve had ( 80 Bronco, 08 Expedition & 06 Escape ) were the Firestone Wilderness A/T shod Explorers. So much so that I bought a second set after wearing out the first…then the recall came along and I had to take them off.
I’ve never found a better tire.
But that was a personal call I made having seen the look and feel of the tires with such low psi in them.