[vandridine]

I hit a large pot hole today on my way to work and blew a hole in my front right tire. I dropped the car off with bmw this morning and they told me they would be replacing the tire. However after I left I started reading up on how replacing one tire on an AWD car can ruin the xdrive system. My car has 13.5k miles. Is there any truth to this?

[Sail Boat]

The MIT mechanical engineers and Cal Tech physicists at your local tire shop (and on the internets) vehemently argue that replacing one tire causes ripples in spacetime and sometimes results in the spontaneous creation of a supermassive black hole.

For the life of me, I can't figure out how racing teams get away with it. They must have Cambridge theoretical physicists on staff.



In all seriousness, go ahead and replace the single tire.

[overcoil]

Most important is that you don't use mismatched tires, example not all the tires are from same manufacture or same model tire.

Some cars might be susceptible to differences in tread depth, but I didn't see any reference to that in BMW Owners Manual or in an AWD Honda Owners Manual - though the Honda product did say it's ideal to replace tires in sets of four or in pairs - but that seems to be safety traction and not pertaining to damaging drivetrain.

[pikcachu]

Originally Posted by vandridine

I hit a large pot hole today on my way to work and blew a hole in my front right tire. I dropped the car off with bmw this morning and they told me they would be replacing the tire. However after I left I started reading up on how replacing one tire on an AWD car can ruin the xdrive system. My car has 13.5k miles. Is there any truth to this?

It depends how much wear you have.... if the wear is not even 1 tire will spin always much faster than the other 3 so the AWD differentials don't like that and it can create premature wear...

[phljeeper]

I just had the same issue but have less miles at 8500. The shop didn’t have any concerns replacing one tire. BTW, the tire manufacturer appears to cover the tires under warranty. I called Pirelli and since the tires had less than 2/32 wear they are reimbursing me 100% for the cost of the new tire. Mine was a sidewalk tear from a huge pothole in NYC.

[Tpeterson]

Originally Posted by pikcachu

It depends how much wear you have.... if the wear is not even 1 tire will spin always much faster than the other 3 so the AWD differentials don't like that and it can create premature wear...

This would be my thinking. Replacing diffs is much more expensive than tires.

[vandridine]

Originally Posted by phljeeper

I just had the same issue but have less miles at 8500. The shop didn’t have any concerns replacing one tire. BTW, the tire manufacturer appears to cover the tires under warranty. I called Pirelli and since the tires had less than 2/32 wear they are reimbursing me 100% for the cost of the new tire. Mine was a sidewalk tear from a huge pothole in NYC.

I called BMW and they said they would look into it for me. They called back and told me if the tires have less then 2/32 tread wear then you can replace the tire. If they have more than 2/32 you should replace all 4 tires for else there will be damage to the transfer case. Sadly i am somewhere between 3/32 and 4/32 so it looks like i will be buying a new set of tires. I am planning on keeping this car for a long time so i am not going to take the chance with ruining the car over tires.

[pikcachu]

Originally Posted by vandridine

I called BMW and they said they would look into it for me. They called back and told me if the tires have less then 2/32 tread wear then you can replace the tire. If they have more than 2/32 you should replace all 4 tires for else there will be damage to the transfer case. Sadly i am somewhere between 3/32 and 4/32 so it looks like i will be buying a new set of tires. I am planning on keeping this car for a long time so i am not going to take the chance with ruining the car over tires.

Discount tire usually has an option where they will replace all the tires for free if you have to replace a tire... it's about $20/tire

https://www.discounttire.com/custome...e/certificates

I always get it for awd cars cause if 1 tire fails you can be out $800

[mdputnam]

You might look into Tire Rack's Tire Shaving service. Here is their article that discusses that service, scroll down to the "Matching Tires by Shaving Them to Maintain Equivalent Tire Tread Depths" section.

[Shovelman]

Let's do the math here. We're discussing 1/16" in a tire with a radius of about 12"

That new tire will rotate one less time in 200 revolutions.

The car has a track of about 5' so it will be about like going around a curve with a radius of about 1000 feet. Hope it can do that all day without blowing up.

Now let's think about minispares for just a second...that should be long enough.

Case closed.

[pikcachu]

Originally Posted by Shovelman

Let's do the math here. We're discussing 1/16" in a tire with a radius of about 12"

That new tire will rotate one less time in 200 revolutions.

The car has a track of about 5' so it will be about like going around a curve with a radius of about 1000 feet. Hope it can do that all day without blowing up.

Now let's think about minispares for just a second...that should be long enough.

Case closed.

Have you ever seen BMW putting a mini spare on an Xdrive ?

[BEM-S4]

I'm surprised no one (at least to my knowledge) offers tire ins that is more $ for better coverage and replaces both tires on the axel.