When I got my SRT-8 it had 37psi in all 4 tires according to the computer, I've never had run flats before so I cant go by the sidewall, but I'm used to running all high performance tires at or just below max psi.
Just wondering if I should stick with that philosophy or does the super stiff sidewall favor airing down from max?
Right now I'm thinking 38 up front and 42 in back.

Thoughts?

My tires are 41's around. I have no idea if this is beneficial.

Max psi on the fronts is 40, rear is 44.

Let me be a bit more specific, when my vehicle first starts, the pressure is 41 all around.

Then, once I start rolling, they go to 39's around.

Hmmmm, I need to read the owner's manual I'm thinkin'.
Mine are around 34 and been that way since I got it.

Look on your driver's door. There is a tire pressure recommendation sticker there. 36 psi front & rear.

Never run at or near max (unless hauling 100's of lbs. of cargo perhaps), go by the door sticker which should be 33 all around when cold. This what the vehicle was designed for, giving you the best combination of tire wear, handling, braking and mileage. 40-ish is way too high as the max is 44 and when warm the tires can gain quite a few lbs. The ride will be harsher the higher you go. 33 is perfect.

34 does feel pretty good!

Mine was delivered set at 34 cold. I only have 115 miles on it now but I've already seen tire temps rise to 39 when driving non-agressively when it's 102 outside.

I best way to figure out what the best pressures are for prolonged aggressive driving is to go to a track (one with turns not a dragstrip) and measure the tire temps after 10-20min of hot laps using a pyrometer. You want a decent balance in temp from inside to outside across the tread when fully hot. Lower pressure if the middle is considerably hotter, raise it if the inside/outside is hotter. Once they are adjusted as good as they get for the track then measure the PSI the next morning on cold tires...that will be pretty close to as good as it gets for performance. The downside is this uses lots of gas, tire and brake pad. The upside is, it's a blast to do and worth it if you can afford the reduced tire and pad life.

mine are around 31 all the time....is that bad?

Sorry guys, I posted wrong info. That's what I get for trying to go from memory without actually having a mind to begin with!!:(
As stated above, the door sticker states 33 psi front & rear cold. That means before you drive the vehicle for the first time that day. However, you will want to check the tires when they are all at the same temp. If one side of the vehicle has been sitting in direct sunlight, then those 2 tires will have more pressure in them from expansion due to the sun's heat. Before you leave the garage is the best time to check your tires.

A reading 2 psi low will definitely effect your gas milage. Also, the tire flexes more which causes more heat to be generated in the rubber. Usually, when you get your tires adjusted correctly, they will stay that way unless there is a problem...slow leak, nail, bad valve stem....or until the weather makes a big temperature change.

These tires are pretty wild actually, sidewalls are rock stiff, tons of feedback and decent grip considering how hard the compound is.
I would prefer to change them to something lighter and grippier when it's time but 285/40/20 is not readily available in anything else.

Mine had WAAAAAAAAAAAY too much air when I got it, after trying a bunch of diff psi's, I now have them all reading 34 cold, and they'll go up to 36/37 when driving. BTW the run flats work good, I got nailed the first week......

Remember the hot weather makes tire pressure go up, cold im at 34 psi all tires, after driving for a while they will read 37-38 psi, max hot pressure is 44psi for our tires.

Remember the hot weather makes tire pressure go up, cold im at 34 psi all tires, after driving for a while they will read 37-38 psi, max hot pressure is 44psi for our tires.

31-32 PSI cold is the minimum. Anything lower triggers the tire temp monitoring system upon start-up. I've tried it in an effort to improve the ride comfort during daily driving.

Mine had WAAAAAAAAAAAY too much air when I got it, after trying a bunch of diff psi's, I now have them all reading 34 cold, and they'll go up to 36/37 when driving. BTW the run flats work good, I got nailed the first week......
This is what I run, 34 at start->37/38 hot (or is that very hot!). Seems to work pretty well! :D

Bummer to hear you got nailed during your first week! :eek:

After spending some time in the tire business, here is what I've learned. The proper tire pressure for the tires on YOUR vehicle depends on a few things. How you drive and the weight of your vehicle being the biggies. That being said, the right tire pressure is the one (or ones, front vs,. rear) that give you even tread wear across the tire. Invest in a tread wear guage and check the tread depth across the tire every 1000 miles or so. If the middle of the tire is wearing faster, the pressure is too high. If the sides are wearing faster, too little. Simple.