YWW

On my 2008 RX350AWD, the factory recommends 30psi for both front and back on the 18-inch Michelin tires and I believe Lexus recommends the same for other model years too for the RX. I know many of you put 35psi in to maintain better gas mileage which I did also for the first 15,000 miles (I rotate the tires every 5000 miles). The ride was a little firm but OK but I did notice the treads in the center section on all 4 tires were wearing faster than the edges which indicated the tires were over inflated (the dealer also pointed that out to me). I then dropped the pressure to 32psi on all 4 tires for the past 10,000 miles. The center treads seem to still be wearing faster than the edges but not as bad as the first 15,000 miles at the higher psi.

Here's my question--has anyone set the tire pressure on your RX exactly to OEM spec's 30 psi? If so, what's your experience on tread wear? Is the wear even? Thanks.

Adamjeeps

My opinion is anywhere between 30-35 is ok. I run about 32.

biff44

I use 35 psi. If I lower it to 30, it drives like it is on marshmallows. MXV4 18" tires. I do not seem to get any more wear in the middle than the edges.

If you are into a "soft ride", go for it. If you want to corner tightly at 80 mph, don't do it!

pauljcl

I have always run 32-33psi - better 'feel' on a 99RX300 and also a 09RX350 (18" rims, MXVs). In both cases, I prefer the ride and have had no uneven wear on tires.

ycl1688

does not the driver's side sticker recommended 30 psi max ?

mandyfig

I used to run 34 psi. But run 36 psi now. I will check on wear middle vs outer. My experience is that outer wears out faster than middle. So I try to prevent outer wear as priority. Which also helps with gas mileage and yes it is a firmer ride.

lexus114

I run the factory spec.30psi. With PA roads,I dont want to put any extra stress on the suspension,ball joints,etc.

Grumpa72

I run just what the manufacturer printed on the sticker. Must be there for some reason! Of course, I recognize that tire pressure is a compromise between ride comfort, tire longevity, tire wear evenness, and other factors, I am sure. That said, I drive a luxury SUV and want it to feel comfortable not like I am driving a gizmo-ed up F150. I got over 45000 out of my OEM Michelins, my wife gets better than 25 mpg (measure & calculated) when she drives conservatively so, yes, I drive with factory specs.

mandyfig

^^solid strategy, what can I say.

YWW

No, it just says "30psi cold tire pressure". However, on the Michelin MXV4 S8 18-inch tire side wall, it does say max pressure 44psi. Don't think anyone pumps the tires to the max though unless the vehicle is being stored for long term storage like a few months.

pauljcl

It recommends 30psi (neither 'max. nor min.), but I didn't like the feel and I found the tires wore more on the edges. For me, 32-33 psi works fine.

pauljcl

Interesting - I'll have to check again, but I believe my MXV "Energy" have a max pressure of 35 psi. -- Yes for storage I also inflate to max. authorized pressure as indicated on sidewall. [On the BMW's Contis, this is 50psi - always worked fine and no flat spots felt after a couple of miles].

LexusPia

My tread wear experience on my RX350 AWD Michelin Energy MXV4 S8 18" tires is identical to what YWW is seeing. I had 35 psi initially and the middle section was wearing faster than the sides on the first 10k miles. The dealer told me to lower the pressure to 28 psi to even out the side tread wear which I did for about 10k miles. I now have them all set at 30 psi exactly the same as the spec and the wear is very even for the past 6k miles. The tires still have decent treads left to last me another year or more.

If some of you are using 35 psi in your RX tires, I find it hard to believe you are not seeing wear in the middle treads since most second generation RX AWDs weigh about the same so they should all experience a similar wear pattern. The dealer is recommending 30 to 31 psi with 32 as the max setting since they have seen many RX with wear in the center treads if the pressure is around 35/36. I know based on my own experience 30 psi is the perfect setting to have for even tire tread wear and good ride.

noz34me

I believe the construction of the tire has more to do with how the tire wears at different pressures rather than the fact that everyone's car weighs the same. Some tires are probably more susceptible to middle tire wear at higher pressures than others.

biff44

What speed rating are your tires? Maybe you have the H instead of the V. The higher speed rating tires have much stiffer wall construction.