Tire replacement with AWD.

[wgriswold]

My 2003 XC70 has four Michlein Defender T & H tires with only 5000 miles on 80,000 mile tires. One of them picked up a screw in the sidewall and is un-replareable. Costco has a road hazard guarantee but the tire has been discontinued. They tell me that they cannot put any other tire on because the car is AWD. What do you all think? Maybe a different tire on the rear is acceptable?

I am trying to avoid buying four tires to replace the ones that I have that have only used 6% of the tread.

Thanks for your advice.

[Astro14]

If the difference in tread depth is 2/32” or less, you’re OK.

[wgriswold]

Costco is telling me that it is not only the circumferance of the tire (difference in tread depth) but also the different treat design which leads to different friction on the road and causes damage to the drive train. I wouldn't think that the system is that sensitive.

[Astro14]

Costco is telling me that it is not only the circumferance of the tire (difference in tread depth) but also the different treat design which leads to different friction on the road and causes damage to the drive train. I wouldn't think that the system is that sensitive.

Well, they're right in that you can't mix tires of different model or construction, even if they're the same brand. The system (you have a Haldex, right?) is that sensitive, but if you're getting a tire of the same model, and the tread depth is within 2/32" - then you're OK, the circumference is is close enough to avoid triggering the Haldex.

Big questions:

What does your owner's manual say?
What is the tread depth on your current tires?

[hoonk]

My 2003 XC70
They tell me that they cannot put any other tire on because the car is AWD.

A 1998-2002 Volvo AWD uses a viscous coupling to "make" the car have/be AWD. Tire diameter is important for those years. (compared to later years of Volvos)

Your 2003 has a haldex system. The car is FWD until it slips enough to send power to the rear wheels. On your 20 year old Volvo - just put A (one) tire on it. Preferably in the rear. And don't worry about any problems created from your choice.

And I hope you understand the "tire technicians" (probably even the "service manager") are unfortunately not going to be the sharpest tool in the shed (or very well paid). How do I know? Owned and worked at a Volvo service shop for 38 years - now I only purchase new cars and keep them for 3 years - I've hired, worked with and fired those "techs". Most have no clue, or on a substance or 2 (at work) and I don't want them working on my car.

(nobody gets 80,000 miles out of a tire! Well actually the tires on a forklift in a warehouse will go that far - but they are solid chunks of rubber with no compliance, no wet weather traction. The 80k tire is a myth, just a sales tactic)

[wgriswold]

The car is FWD until it slips enough to send power to the rear wheels. On your 20 year old Volvo - just put A (one) tire on it. Preferably in the rear. And don't worry about any problems created from your choice.

A

Thanks for the reply. That is what I thought, but it is very helpful to hear it from someone much more knowledgeable than me.