GSman

iTrader: (2)

What tire pressure should I be using with the stock 17" Potenza RE030? The tire says a maximum of 51 psi and the owners manual recommends 33 psi.

Thanks,

2SAVVY

35 pounds is what I am running.. Gives it a bit more handling at that pressure.. I found 33 pounds to be too spongy.. Hope that helps!

TMitchell

Always start with the amount of air pressure that is stated in the owners manual and on the door jamb. The amount on the sidewall would apply to any application the tire might be used for. It could be conceivable that a car might come out that recommended 55 psi for the rear tires, this would let you know you couldn't use this particular tire since it is only rated at up to 51 psi. The BMW 540I that I owned recommened 33 in front 41 in rear tires. I use a tire depth gage to check for even wear.

duster

I went on a test drive with a lexus tech to have him hear some rattles first hand. I mentioned that I was considering the L-tuned suspension stuff to improve the handling.

He suggested going to 38 on all my 17" tires to firm up the ride.

So far I really like it.

BTW this guy spent a number of years with Porsche before moving over to LEx.

RealMarty

I found that 33 was a good balance.

At 35 the car felt better around town, but tended to oversteer and wander more at speed (with the original '98 steering ecu). And unfortunately the RE030 is such a terrible tire it won't feel any good no matter what the pressure.

Going as far as 38 will make it stiffer, but you'll also wear the tire out faster in the center (and oversteer). If you want better handling the answer is suspension changes and better tires.

duster

Yes I am watching the tire wear closely. I should clarify that I have the michelin pilot sports.

Running at 33 for a while and properly rotating the tires, I was noticing feathering" on the outside of the tire. This wear was also leading to increased noise.

With the increase to 38, the tires are quiter and run much "free-er" (less drag) on the highway.

The pilot sports also have a nice center bead that gives the car good directional stability.

Anyway, the comment about tire wear is a good one and I will be tracking that as my experiment continues. Also, the ride is obviously a little rougher.

Where would I get a tire tread depth tool to accurately monitor/measure tire wear?

RealMarty

Check with NAPA, Pep Boys, Auto Zone or one of the other auto parts stores. The gauge is generally a small cylinder with a "pin" with depth markings on it. You push the pin into the tire groove until the cylinder stops the movement and read the depth directly from the pin.

As for the pressure. If you are cornering aggressively the higher pressure will reduce the cupping and feel more responsive. However, be careful in the wet. At that pressure you have a smaller tire patch on the road and an oversteer condition. You could be surprised by their breaking loose earlier than you expect.

BTW, IMO the Michelin Pilot is a great tire choice although for my next set I'm going to investigate the the Toyo's. They definitely appear to be worth checking out.

duster

I appreciate the info on the tire gauge and the heads up on the oversteer/wet conditions.

I also have my eye on the toyos for the next set.

joeyGS430

but I find my 2001 GS430 to be soooo noisy. Duster says the tires got quieter at 38psi so I may give it a shot.

QUESTION: Where does the Michelin Pilot fall in the spectrum of stock tires for the Lexus?

RealMarty

I love my Michelins, but others say they are noisy. If you want a quiet tire I think there's a thread called " I want quiet, quiet, quiet" that deals with the quietest tires for the GSs. Try searching for it.

RealMarty

I've been thinking about this question in light of my overwhelming dislike for the Bridgestone 030s. IMO there are few tires worse than they in the realm of high-performance tires. Seriously -- they suck.

Thus I now believe the correct pressure for them is about 125 psi - to be applied under controlled safe conditions. The pressure will be so high they will burst - then they can be thrown away and replaced with a decent tire.

lexguynj

Now that made me laugh! That was pretty funny. But most of us like you are stuck with our stock tires for now, since would be a hit in the pocket if we were to just discard them now for new ones.

But the debate still continues, what is the PSI needed for both front and back. It seems based on the posts that it's all over the place!

RealMarty

33-35 psi. And that's my FINAL answer.

lexguynj

Sounds good, but are you sure you don't want to call a friend, since we have already polled the audience? A lot can be riding on this answer (No pun intended)! HA!

RealMarty

I already called.

He hung up on Regis.