Correct tire pressure?

[94LegWagon]

Have been going off what Subaru put in the drivers side door jam, but I have 205/55/16 tires. Should I run something more than 32psi? Since the tire is lower profile than stock...

[SubaruFred]

IMHO, 32psi should work great with those tires.

[kimokalihi]

You should run whatever the tires say to run.

[Legacy777]

You don't necessarily want to run what the tires say, as that is typically a max pressure at max load capacity.

That actually gets into another issue...and I know this is kind of an aside from the original question. Tires have different load ratings, and are matched to the vehicle weight or anticipated gross vehicle weight. Running different tires, especially very low profile tires, or sometimes even cheaper tires, you may not have enough load carrying capacity with that particular tire. What tends to happen when the tire is overloaded is that it heats up and with the increase in temperature the materials breakdown quicker and can lead to a failure/blow out. So just a little tid bit of info....same can happen if you don't have enough air in the tire.

As for the original question, I'd run around the recommended tire pressure in the door jam. I typically will run a little higher pressure than what the manufacturer recommends 1-2 psi on the Impreza and 2-4 psi on the Legacy. This is primarily because I'm a performance oriented driver and like better handling vs. more comfortable ride. You don't want to go all the way to the tire's max pressure at max load all the time, especially if you don't have that extra load. It can lead to the center part of the tire wearing sooner and a reduced grip.

Overall, tire pressure is a rather subjective thing in my book. It will depend on the tire manufacturer, construction, etc. I've played with tire pressures for a bit, especially on the Legacy until I found one I liked. Sometimes even a 1/2 psi of difference can make a big change in how the car handles.

[SubaruFred]

^^^ Great answer!

Just as an example of why not to use the max inflation pressure on the tire, I was recently contemplating a set of 195-75-14 BFG T/A KOs for my 3200lb Legacy wagon. The BFGs are rated at 65psi max at GVW of 6840lbs! I'm sure that 32-35psi would work much better for those tires on my car.

[evolutionmovement]

I usually run just below the pressure that will result in the center going bald (38-42). The Subaru liked it better around 36-38. Currently, due to NTBs inability to replace valve stems resulting in 3 leaks that need to be pumped up every few days, I set the Mazda's at friggin' 50 (and still one goes below 20 in 3 days). The dealer's going to hate me after I trade it in!

Weather is also a factor in tire pressure. If you're driving through the desert in summer, you don't want to run too high since the air expands. Cold weather will drop it.

[SubaruFred]

Gotta love tire monkeys. I once bought 4 new wheels and tires at Pep Boys. On their first attempt they managed to destroy all 4 wheels and 20 lug nuts with an impact wrench. On their second try they managed to install the new wheels and nuts without destroying them but installed 2 of the the tires with a paper label between the bead and rim. Third try fixed that and the fourth try got the balance right. Oh yeah, they never got the tire pressure set correctly, I took care of that.

[beanis05]

Make sure to check the tire pressure occasionally. I do it twice a month in the winter and about once a month in the summer.

[93Leg-c]

I have 205/55 16 Bridgestone re92's and I run 39-40 psi in the front and 35-36 psi in the back. If I ran 35 psi in the front, the outside edges of the tires would wear faster than the middle. The re92's have a rating of 44 psi max pressure when cold.

[kimokalihi]

Took my car into les schwab to have them fix a slow leak I had on one tire. They didn't do it because the tire had too much wear. I left pissed off and now I was filling it up and all the other tires were at 40 psi. I set them at 34 front/ 32 rear. Door sticker flsays 30 front 29 rear.

[kleinkid]

I recently had a discussion with someone about tire pressures. The other person said he inflates his tires to the max pressure indicated on the tire sidewall. He wanted better gas mileage. I believe it was around 45psi.

I suggested he use what the car manufacturer, in this case Subaru, states to use for this model, as indicated in the owners manual and on the drivers side door post.

He did not agree and insisted that the correct pressure was the max pressure listed on the tire.

I explained that the ride would be terrible and would cause premature wear on the center of the tread area.

I personally use about one pound more on each tire than what Subaru says for my model.

Here is what Goodyear says about proper tire inflation.

http://answers.yahoo.com/question/index ... 217AALdq8R