Bocatrip

My 2001 Lexus 430 with 115,000 miles has 4 Michelin Primacy MXV4 17s with 15,000 miles on them. I have rotated them twice (cross rotation) and all 4 tires have even tread across except that the outer and inner edges of the tires show more wear. I probably had the tires inflated around 33lbs most of the time. I showed the wear to a tire shop which told me that the LS430 characteristically leans over to the sides of the tires when turning hard and this is normal wear. I was thinking that possibly my tires were underinflated. I have 6/32nds on every tire and the inside and outsides of every tire show the same wear (all show 3/32nds inside and outside). The shop also mentioned that only the middle treads are measured when considering any warranty issues. I have plenty of meat left on my tires and am now keeping them at a constant 35lbs all around. My car steers straight as an arrow and I have no suspension issues that I'm aware of. If it were suspension related I would think either the inside or outsides would be worn more than the other. For those with Primacy MXV4s, how are they wearing? What do you guys think?

ma61

Did I miss the part where you said you had it aligned...?

Worn suspension bushings can also cause abnormal wear. But you wont be able to find that out without having a technician inspect the suspension components.

Bocatrip

When I had my car brought in for rotations, they run it through for those quick alignment check machines and it has always came up green all around. They love to sell you alignments, but have not asked. I did go to an alignment shop awhile ago and after looking at my tires, he told me it was not necessary and I would be throwing away money as my tires looked good to him. Once again, even if it were worn control arm bushings which is common.......how is that all 4 tires (after measuring with tire depth gauge) show the identical amount of wear on the inner and outsides? This is the reason I am leaning towards underinflation. I live in Florida where the roads are brutally hot.

doodoo

iTrader: (8)

It sounds like under inflation. If it is stock size, I usually do 2 psi above the recommended listed on the door jamb. I am lowered and run a staggered setup, my tie wear is even even with some negative camber. You can check an alignment as well, maybe your toe is out and you have abnormal tire wear. And lastly suspension parts like tie rods or check bushings. Good luck in finding your problem

jayclapp

MXV4 tire pattern is for one direction rotation, meaning that you can only rotate front to rear on the same side and cannot cross rotate unless the tire unless unmounted and reinstalled with the tire pattern in the right direction.

RA40

iTrader: (6)

Difficult to say, would be nice to see some alignment specs to verify what may be happening.

Tom57

Sounds like under-inflation. I too try to keep PSI about 2 above recommended = 35 psi. I'm at 60K+ miles and still have tread left (before wear bars). Given that you apparently have the same wear pattern on all 4 tires would tend to suggest that it's not alignment.

Bocatrip

Jayclapp.....Actually the MXV4 is asymmetrical and can be cross rotated which gives each tire an opportunity to be on every position of the car sooner or later. Great for even wear.

ma61

I misread this, I thought you just said the inner edge was worn.

Both outer and inner wear would indicate underinflation as previously stated, but if you are running at the correct PSI then I'm not sure. Unless your tire pressure gauge is incorrect.

I dont know if I can agree with jayclapp, I dont see how running a directional tire the wrong way would affect tread wear. I think the most that would happen is the tires wouldnt be able to evacuate rain or snow as they were designed.

Bocatrip

Thanks Tom57 and everyone for all their input. Yes, under-inflation is where my thoughts are now. Lexus is not specific on tire pressure for V rated tires. H=130mph and 32psi, W=168mph and 35 psi. No mention of V rated...maybe 33psi? I might need to try and stay as close to 35lbs as possible. It might require going to 36-37lbs so that I don't fall below 35. I watch my tires constantly and if I see any signs of over inflation (excessive middle tread wear), I can make the correction. In addition, tires lose air fairly quickly and need to be checked every 30 days.

Tom57

Since PSI is based upon cold air inflation, I check tire pressure in the early morning after the tires have cooled overnight to get the most accurate cold tire inflation readings. Even a warm tire will show a slightly higher PSI reading (which is a lower cold air PSI) resulting in low or under-inflation at colder temps.

Bocatrip

I checked every tire with a tire tread depth gauge going from the outer edge inwards, covering every tread along the way. I am now convinced that my issue was under-inflation. The outer treads on opposite sides of the tire have lowest at 3/32nds. As I moved from the outer tread closer to the center, the depth increases to a little under 6/32nds while the dead middle is exactly 6/32nds. Going to the other side of the tire is the opposite result as the depth decreases slightly from the middle. Every tire reads approximately the same which confirms my conclusion of under-inflation. I am now planning on having all my tires replaced. The inflation needs to be at a constant 35psi (when cold in morning) or slightly higher for my car.