How do you determin the correct puressure for best wear and handleing? The tires I bought (NITTO 555) only have a max P.S.I. and its 44 lbs.

 

GM recommends 30psi F/R for 4th gen F-bodies. This is true regardless of tire brand.

Personally I use 32 front/30 rear. I've seen excellent wear results with these pressures and standard street driving.

These recommendations are for standard Z-rated street tires. Competition tires may vary depending on purpose and conditions.

 

That is perfect! I just lowered the front to 32, I will do the rear next. The tire shop had them at 40. Thanks man!..

 

Since I've had my car new in 1998, I've always kept all 4 tires at 40-42psi. Perfect wear every time and well over 15,000 miles per set. The damn Nittos last almost 20,000.

Goodyear GS-D3's in the rear 315's
nitro 555 Extreme in the front 275's

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I agree low tire pressure wears tires out quick on the sides.I like 40psi.Look at all the wore out tires at a tire shop most of them is wore out on the sides and the middle looks new.

 

I use a probe-type pyrometer to check tire contact patch temps after a long highway drive. In the summer on [265,275]/40/17's that was around 32F/30R hot. But I haven't done it on the 315's.

 

not the way we should be driving...burn out centers baby!!!

i run my nitto DR's @ 24

 

I shoot to have 32psi in all four when hot for street but that changes when I go to the track.

 

I normally run 32/30 psi and have a even wear pattern.

 

Always 30 psi to 32 psi here and very even wear since the car was new.
LS6427, I would think having 40 psi in these tires would cause a really harsh ride. No??? Any excessive wear in the middle tread area?? You are 10 lbs over recommended. I know your set-up is modified but if I had 40 psi in my GS-D3's I would be wearing them out. Currently have 14,000 miles on them and 20,000+ is almost certain.

 

30-32psi is not "low", it's the OEM recommended pressure for these cars with stock tire sizes, and if that PSI is properly maintained you will see even wear at a normal rate on a Z-rated street tire. What often happens is that people don't bother to check the pressure often enough and PSI drops well below the recommended rating, especially when cooler weather comes.

I've got 30k miles on the current set of BFG KDWSs on my '02, and the wear pattern is perfect....plus a good bit of tread still remaining. I've maintained a constant 32F/30R PSI in these tires at all times. They are going to wear out from age/dry rot before running out of tread.

 

I run with 38 in all 4, I maintain regular tire rotations and after 20k miles all 4 tires are at 7/32's tread depth both in the center and on the sides as long as you don't go below 32 or above 40 tires should wear relatively even go above 42 or so and you'll start seeing increased wear in the center, go below 30 and you'll be wearing out the sides. Between 32 and 40 is the sweet spot for daily driving

 

30psi (cold) is the factory recommendation and will NOT cause significant uneven wear during typical daily driving on regular street tires in the factory sizes unless you have an issue with steering/suspension components or have made significant changes to weight/weight distribution. Again, uneven wear (that isn't due to steering/suspension issues) comes from a failure to maintain this recommended pressure. If you set it at 30psi in July and then don't check it again until spring, it will probably have dropped to 26psi or lower in a cold climate over the winter.

32psi up front will help to compensate for the uneven weight distribution, and would be even more helpful if you have added extra weight to the front (such as an iron block, supercharger kit with associated parts, etc.)

30psi in the rear should be ideal at stock weight, but if you're carrying a heavy load out back then you may want to raise the rears to 32psi as well.

I've seen an excellent wear pattern over the last 30k miles on my current tires which have been consistantly maintained at 32F/30R (cold).

 

Good information^ I have always used 32psi up front and 30psi on the rear tires.

 

Hence why I said that below 30 will start to cause uneven wear, I said I wouldn't go below 32 earlier in the post simply bc I've noticed my handling, traction in inclimate weather and fuel economy are slightly better in the 35-38 range.

 

^How does it ride? What MPG changes have you noticed compared to a 32psi or lower?

 

At 38 compared to 32 my highway mpg went from 16.7 to 18.3. and does seem to ride smoother as well

 

In my personal experience, I've always noticed a harsher ride with higher PSI.

 

Good point on checking tire pressure often.My tires are usually 40 when hot cold is around 36.I just like how the car feels so much less rolling resistance.Deffinately feel the bumps.Now my nitto 555rs like around 25 for a whole lot more rolling resistance.

 

I will agree at some times if I'm driving around these shitty *** city and county roads we have around here higher psi will make for a rougher ride, but 90% of my driving is done on the highway so it rarely is an issue and on smooth highway it rides amazing so where you do the majority of your driving is another thing to consider simply to make a more comfortable ride for yourself. Thanks for sayin tht rpm wouldn't have even thought about the condition of the road you drive on if it wasn't for that post. Brain fart on my part lol