Tires: Honda CRV, tire diameter, air tank

Question
My mother has a 2008 Honda CRV with about 15,000 miles on it.  She ran over a piece of steel that caused a leak and the tire went flat overnight.  I pumped the tire up with an air tank and she took her vehicle to a tire shop.  The tire shop told her that the steel had punctured her sidewall (the hole "I" saw was in the middle of the tread and the sidewall looked fine to me).  They also told her that she needed to replace all FOUR of her tires because just replacing the one tire would cause her transmission to fail - because, according to them, all the tires have to be exactly the same.  They said they would refuse to replace just the one tire.

Of course, I know that it is best not to mix sizes of tires, etc, but I have never heard that if ONE tire has to be replaced, the other THREE have to be replaced as well.  Like I said before, her tires had only 15,000 miles on them and they were in excellent shape.  They also said that if the transmission failed, the warranty wouldn't cover it because of the new tire being mixed with the old tires.

Is there any truth to what they told her?

Answer
Steve,

The problem is that some AWD's are sensitive to differences in tire diameter and require that all 4 tires be very close in diameter.  On the other hand, some are not.  But it is nearly impossible for a tire shop to be able to know which is which, so they fall back on a safe position, which is change all 4 or none at all.

So is your Mom's CRV one of the sensitive ones or not?  That information is supposed to be in the owners manual - and sometimes it is and sometimes it is not.  You can be sure you have a sensitive vehicle if the owners manual gives you a tolerance.  If it doesn't it may be sensitive or not.

So if your owner's manual doesn't say, call Honda and ask them.