LexusPia

My tires are V rated and they are OEM. I'm not aware of any RX OEM tires at least on the 18-inch come with H speed rating unless the owners changed from V to H to save some money on the replacement set. After the initial trial and error on higher inflation, the 30psi seems to work out for me for very even tread wear and comfortable ride. At the current wear rate on my Michelins Energy MXV4 S8, I'm sure I can get about 40k miles out of them. Seems like others are also getting similar mileage out of them Michelins. They are excellent tires. Can't complain about them.

biff44

The reason I ask is that when I bought replacement tires, they asked if I wanted V or H. The V was, of course, more expensive. Apparently there is a big difference in construction, especially the sidewall thickness.

Odd that some of us get away with even wear at 35, and others have to use 30 psi! Possibly the way you drive, or the road conditions? I drive pretty fast on corners, so maybe I wear away the tire edges where a more conservative driver would not.

Obviously, an out of kilter front end will grind away the tires. Does your RX pull to one side?

Are you sure of the tire pressure? Got a good tire guage? Check it against another?

lexus114

the "V" rated tires also have less rolling resistance,hence a quicker RX.... downside,they wear quicker.

mandyfig

Maybe I should go back to 34 psi. Ride is a little stiff on 36's.

pauljcl

As I have written - in my opinion: 33 psi (+/-) is the best tire pressure for me (09RX350 AWD). Above give me a 'jittery' ride, and at 30 and below, it feels like driving in molasses. The oscillation rate (tuning) of the suspension conflicts with above 33; it does not filter out the harshness and I have the feeling it 'crashes' rather than absorbs. Try it and let us know what you think...

dedas1

Hi. Sorry for joining in late. I have found it hard to believe that factory setting of 30 PSI is right. It is what the manual says and recommended. My wife drives this (RX400h AWD) car and in our previous Town and Country, we had the same problem. Side tread wore faster than middle, and we were getting uneven wear on the outsides based upon factory and dealer recommendations. I have always said my wife drives like a maniac. She corners at 10-15 mph ( exaggeration) , but she does corner at a high speed. I think this contributes to the corner wear. But I would assume it should only be the outer treads and not all the way around, but inside and outside tread. Anyway, we run at 35-36 psi without significant difference in ride, maybe a little firmer.

My delemma is that despite running PSI at 35, we are still seeing the outer tread wearing. I just checked now and the middle still had more tread than the sides. I was thinking of boosting to maybe 38 psi.

Anybody with thoughts would be appreciated.

Thanks

IwillNFAMD

Ok, now I do believe that between my factory specked 2007 and 2009 rx350's I have both outfitted with dueler alenzas. The 07 came with same but were newly used with 18000 miles. After keeping them specked at factory- they were spent at 23000. Dealer then bought 4 of the five, not to mention spare was plugged- nice huh? So, I ran initially the factory recommended numbers and the tires wear very fast- changed to 40 and yes they tend to wear more in the center but they last twice as long. My 09 is now 20000 and I will make this winter no problem. Guessing getting close to 30000, despite tires being rated for much longer. I believe it has to do with the windy roads in PA.

infinirx

lol! When I first got my RX I put it to 44psi thinking "that's an odd, high number" hehe.

biff44

It might be that some of us (me included) drive like bats out of hell, and normally would have a lot of tire edge wear unless we pumped up the pressure. Others who drive conservatively probably need less air pressure.

When I go on a long trip (500 miles+) with my wife in the car, I do lower the pressure to maybe 32 because she complains about the car being too rough-handling. She LIKES the squishy feel.

Koz

If your vehicle is wearing tires on the inside or outside (not both) you may want your wheel alignment checked. It is probably not caused by tire pressure. If the tires are over-inflated you will see the center wear. If they are under-inflated you will see the inside tread AND outside tread wear. I had to set the tow to 0 (which is not OEM spec) to get even tire wear on my IS.

Koz

mandyfig

I have been on 34's and it seems to be good for me. I see more wear on the center still. Maybe drop another 2 psi, back to 32. Until then 34's.

howdybob22

++1

visual

It all depends on which tires you have. I have bf and 33-34 lb is great.

jfelbab

Lexus recommends 30 psi when the tire is cold. When you drive for a while the sidewall flexes and generates heat. A tire is then often 20°-30° F hotter which equates to two to three pounds of added air pressure. If you set your tire at 35 psi cold it likely will be 37-38 psi after driving a while. It's not surprising that a tire would wear in the center more than at the edges at that pressure.

In my experience, the best all around tire pressure for good handling, ride comfort and even tire wear is generally between 30 and 32 psi cold. I've tried various pressures and found that increasing the tire pressure did not yield any appreciable increase in gas mileage. Pressures above 32 psi imparted a "truck-like" ride, which is not what I wanted in my luxury SUV. Below 30 psi gave a very soft ride and felt like the tire was rolling over in hard cornering, especially with with the Goodyears and Michelins. The Alenzas, no so much.

Just a pound or two can make the vehicle ride and handle quite differently. I'd recommend trying various pressures and find what you like best but remember that the manufacturer chose 30 psi for a reason and that they have test tracks and engineers who want you to be safe and enjoy the vehicle.

It is a good idea to check your tire pressure frequently. I check mine weekly as the seasons change. Yesterday the high temperature here was 63°, today it is headed to 88°. 25°=2-3 psi difference in the tires.

My Alenza's now have 40k miles on them and evenly measure 9/32nds all around.

mandyfig

You are right on. Tires accumulate 2 psi easily depending on the season and how hard the driving is.

Once in a while I have to release pressure. I only do this while measuring cold. Most of the time I add a psi or 2.

I am at 32 now because I am seeing center wear more than the outer on the Michelins. I used to run 34's all the time. I would see 36's on a Saturday morning sometimes.

I do check my pressure every 2 weeks minimum. I have purchased a small air compressor just for this purpose. I have a long enough air hose that it is convenient to use. A good pressure gage is a must, too.