Omidjuly4

Hi

I have a Lexus RX350 AWD 2007. My rear tiers h are not round beacouse the previous owner had to little tire pressure in two of the tiers and it has been standing still for a couple of months.

I have been recomended do change these almost brand new tiers. Since this is my first awd i wonder if i have to get the exact same tire or will i damage the transfer case?

jfelbab

If the tires are over 6 years old, I'd recommend replacing all 4. Rubber ages, even faster if not used and flexed to distribute the ozone inhibitors. Just because a tire has a lot of tread remaining does not mean it is safe.

To find the date on your tire look for a string of letters and numbers beginning with DOT. Look to the last four digits where the 1st pair is the week and the last pair the year the tire was manufactured.

If the tires are really "almost brand new" and not over 6 years old, I'd just air them up to 32-35 psi and drive them enough to heat them up, say an hour on the highway. This should remove any flatspotting and you should be good.

Who recommended that you replace them? While having a different pair installed shouldn't cause your transfer case any stress, I'd want to replace all four to maintain consistent handling in all weather conditions.

Omidjuly4

Hi and thanks

The tiers are 1 yers old and the tire shop told me i have to replace them (2) i have driven with 45 psi for over than 1h i usaly have 45 psi .

So if its ok with the transfercase i can buy other tiers ?

Rainbird

Of course the tire shop would want you to replace them, after all their business is selling tires. Don't leave your tires at 45 psi you will have short life on them doing that. Lexus recommends 30 I run my tires at 32.

jfelbab

The more important issue is that by mixing tires you are changing the traction of the vehicle front to back. This is not a good idea, IMO. While it may not damage your driveline it could cost you a loss of control in an emergency situation. As I said, if it were me and I really needed to replace the tires I'd replace all four.

If the tires are one year old, they should be under some sort of manufacturer warranty. Tell me the brand name and size of tires and also the date of manufacture. Also please tell me exactly why you feel they are a problem. What problems are they exhibiting?

Some added material on the subject of mixing tires: http://www.tirerack.com/tires/tirete....jsp?techid=18

Lexi011

I concur with what is being said... When dealing with Awd vehicles it is recommended you change all tires at once... Just my 2 cents

Omidjuly4

Thanks everbody for the good advice.
My tires are 235 / 55 r18 Nokian hakkapelitta R snow tiers. Reason i need to change the is they are wobbling and it cant get rid of it by re balancing them.

I guess i have to buy 4 new onee

jfelbab

The above cautions on mixing different tires are even more significant for snow tires.

I don't know if this is of any help but here is Nokian's warranty info: http://www.nokiantires.com/nokian-warranty

Wobbling can be caused by a number of things. Here is a link on how to identify the exact cause: http://www.souzastireservice.com/tir...d-wobbles.aspx

Omidjuly4

Thank you so much for the help, i contacted Nokian herr in Sweden. Haven't got a answer from them yet. That's very interesting reading . I'm at the tire shop now to buy new tiers .

I have always heads hire tire pressure with perfect wear. Now I'm using 45 psi on my 235 / 55 R 18. Any gommens on that?

jfelbab

I'd suggest your tire pressure should be at or within a couple pounds of what the auto manufacturer suggests. This info is on a decal in your driver side door sill. The manufacturer has chosen the best tire pressure to provide comfort and capable handling. Gross over or under inflation can cause a loss of control, increased stopping distances and lead to an accident.

Omidjuly4

Ok thanks alot, i love this forum

DixieLex

better MPG, smoother, etc.