DadWagon450

I got a flat recently by blowing out the sidewall on my RF in a pothole. When I got the new tire on my front driver side i took it into a local shop to have it realigned bc it was pulling slight right. The shop owner informed me that since I have an ALL WHEEL Drive that the other 3 tires need to be replaced or else I'll damage my drive train.The 3 other tires still have plenty of life left in them to get another 10K miles or so. I've heard of mechanics saying this before but have found it to be some BS. I've owned many other all wheel drive vehicles and have replaced 1 tire due to damage and never had a problem with the drive train getting damaged. They did realign my car since it was off.

All 4 of my tires are the same brand and tread pattern . Is this some BS or is this some concern?

My plan was to buy some aftermarket rims and switch to non rf's and go for a square setup. Currently my E450 wagon has a staggered set up right now.

JTK44

This is more theory than practical: In theory on an AWD car the size of the tires should be the same. That is the theory and by extrapolation, a new tire will be slightly bigger than a tire with mileage on it.

But here is the reality: a new tire will have between 9/32 and 10/32 of tread life. A tire with 10,000 miles left probably about 6/32 of tread life left. That difference, 3/32 is miniscule. It is less than than the difference between 30 psi vs. 35 psi.

Just my $.02. Hope it helps.

DadWagon450

That was my same exact thoughts, just needed some backup. In practice in the real world, I’ve never heard of someone damaging their drivetrain on a new tire where the other 3 tires are used and all are the same tire. I haven’t seen this in forums as well

Keith66

Agreed, you are both thinking correctly. Modern AWD systems are not that sensitive and fragile even though many keep repeating these old wives tales.

It's absolute BS and perpetuated to sell more tires, it's an AWD gravy train of tire sales.

If you think about it, if what they are saying is true, most automotive forums and most garages would be full of broken AWD cars and trucks because of mismatched tires, but it just flat-out doesn't happen.

Hundens

Remember, it is an industry based on larceny, and the larceny starts with the dealers. I had one suggest I replace all the tires because they were over seven years old. Michelin pilot sports with maybe 25,000 miles on them. The car is only used seasonally. When the dealer wants your money, it is better to always say no and then work from there.

JTK44

There is an old adage:

ua549

Tires age even if the tread is not worn. UV light is a major cause sidewall deterioration due to age. I wouldn't drive on tires that are more than 3 years oldor show signs of sidewall cracking.