34R/40F tire pressure.

[joseph]

I used to run 36 PSI all around on my 255 tires, now I changed to 34 Rear and 40 Front, 34 rear for better grip, because they tend to spin when I take off hard, and 40 front to reduce drag, get better steering response and better mpg.
What do you think of this set-up?
Any opinion is welcome.

[joseph]

No one cares I guess.

[Jaak]

Sounds like an interesting idea....

[Slim]

Well its a good thing you bumped this or I never would've seen it. I run 32 psi all the way around. My car is a bit heavier than yours I think, and I have 20's but I was noticing a little more wear in the center of the tread with it at 36. Although it could be from all the burn outs!

[racergary]

I run a little more in my front as well

something like 38/40f and 36/38r......since I don't get on her hard very often,the higher pressure in the rear doesn't bother me

[NAS T MAG]

1. Check tire pressure recommended on driver door.
2. Follow those recommendations.

I run 30 lbs and check weekly. If I don't get 50,000 to 60,000 miles out of a set of tires, I'm pissed.

[MattRobertson]

Running that air in the tires will cause the centers to wear more quickly than the edges. I have a set of tires stacked in the garage right now that show these effects.

In hard cornering use I found that increasing the tire pressure in the front like that also caused the tires to break loose. Or more accurately it makes it easier for them to break loose in a corner and get pushed thru that same corner by the power coming from the rears. the car still corners, but it does so with the fronts sliding and the rears gripping and pushing. Wears the hell out of the tires. Thats what did my Toyo Proxes in too, come to think of it. Or at least it scrubbed off the tread a whole lot faster than it would have worn off otherwise.

In less-than-really-hard cornering I found the Proxes and RSA's were much more likely to chatter and stutter rather than grab 100% thru said corner.

In a straight line they'll do exactly what you are talking about, and raised pressure is what you want in the fronts on the drag strip.

[joseph]

1. Check tire pressure recommended on driver door.
2. Follow those recommendations.

I run 30 lbs and check weekly. If I don't get 50,000 to 60,000 miles out of a set of tires, I'm pissed.

Isn't that what people who know nothing about cars say?
30 is too low, everybody knows that, run 34 or 36 and you'll get better MPG.

[joseph]

After a few hard starts from lights, I noticed it grips pretty good at 34R and my steering is much lighter with 40F.
I got those big 255 tires and they look low on pressure in the rear compared to the front, but they are at 34, I double checked.
Now with 34 in the rear, I barely get any spinning and it launches pretty hard and steady.
I'll try with ESP off and floor it and see if it still grips good.

[TrippHemi]

Changing the pressure differential between the front and rear tires can have significant effects on the car's handling. If the pressure is higher in the fronts, the handling will tend to be tight, as MattRobertson said. The converse is also true. By playing with tire pressures, I loosened up my Rabbit back in the early 80s by running more pressure in the rears.

You don't need big pressure differences to improve your handling. 1 or 2 lbs. may be all that's needed to get your handling closer to your sweet spot. Bigger differences, bigger changes. That said, running off-spec pressures will likely shorten tire life, but it's your choice. It's a trade-off.

If my tires last more than 25k miles, I'm a happy bunny.

[joseph]

Changing the pressure differential between the front and rear tires can have significant effects on the car's handling. If the pressure is higher in the fronts, the handling will tend to be tight, as MattRobertson said. The converse is also true. By playing with tire pressures, I loosened up my Rabbit back in the early 80s by running more pressure in the rears.

You don't need big pressure differences to improve your handling. 1 or 2 lbs. may be all that's needed to get your handling closer to your sweet spot. Bigger differences, bigger changes. That said, running off-spec pressures will likely shorten tire life, but it's your choice. It's a trade-off.

If my tires last more than 25k miles, I'm a happy bunny.

I agree, 34 rear seems to do it with my 255 TOYOs, at 36 they would spin (right side only) for half a sec before hooking up, now it hooks up real nice even when I floor it with ESP off, I'll probably go 38 front for 3 reasons, front is a bit hard when I hit bump... nothing bad but a bit softer would be nice, I don't want to wear out the tread unevenly in the middle, and I don't want to have too much of a difference in PSI between front and rear. I had 36 front before but it was straining the power steering when parking (not moving) at 40 it would turn easily, so 38 should be a good compromise for the front.

[Jaak]

Ever look at the tire pressure they run at the SRT Track Experience? At Watkins Glen, 45 lbs all the way around, so the sidewalls don't roll under.

It all depends on what you're doing, as to what pressure to run.

[joseph]

Ever look at the tire pressure they run at the SRT Track Experience? At Watkins Glen, 45 lbs all the way around, so the sidewalls don't roll under.

It all depends on what you're doing, as to what pressure to run.

Do the tires grip well with that kind of pressure?
I've read recently that they go as low as 20psi rear for the track so as to not spin and 50 front to reduce rolling resistance.