The difference in tread depth must not exceed 2 mm on one axle. The BMW dealer is correct, you can only replace the tire that is worn to 4/32", but tire salesmen will disagree.
Do you really think three years of hitting potholes and other imperfections (in the OPās case) has no effect? Iām afraid I disagree.
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Hi Keith,
My car ws in a small fender bender and the front end was redone because the cars collidated at front wheel 20K worth of rebuild. In my case would it be better to a) get an alignment b) if so, go to dealer they have precison equip. C) the repair shop is Penske auto who works on BMW repairs out here in AZ
BMW says to put weights in both front seats, in the trunk and have a full tank of gas in order to do a proper alignment, IIRC 150# each front seat, and 50# in the trunkā¦ the weight lowers the vehicle which in turn changes all the angles including toeā¦ Take it how you want toā¦
Most AWD systems recommend/require all 4 tires match within about 3/32 of an inch highest to lowest tread if all 4 tires are the same size, if staggered sizes, then either both front or both rear changed in pairsā¦ Some AWD systems you can do 2 at a time (same axle) and a very few (Kia/Hyundai) one at a time is fine (last I checked)ā¦
I have called some dealers and they said different things (same brand) but according to the Owners Manual it stated different from the dealerā¦ So I would go by the Owners Manual 1st, Service Manager of your brand 2ndā¦ With a very expensive drive line Iād rather be safe then soundā¦
Most RFT (run flat tires) specify not to repair but not all, Bridgestone on some RFT tires as long as it has not been driven on lower then 15 psi and over 50 miles at 50 MPH it can be repairedā¦
I think Pirelli says donāt add air if it goes flat (I think that is over kill lol)ā¦
At 2/32 DOT says you are unsafe, at 4-5/32 you have lost most of your wet weather traction, and the rubber can become harder and not grip as well in braking, cornering situationsā¦
Not all tires are created equal, there IS a difference in tread compound as far as wet/dry tractionā¦ And rather you drive fast or not, a corner can sneak up on you sometimes as well as the other drivers might not be paying attention and you might have to do some defensive drivingā¦ So even if I have to eat cheap I always put high end tires on all mine and immediate familyās vehiclesā¦ Most every vehicle I have bought in the last 20 years I have almost always put new better tires on them (my daughter could not wait to get the Michelins off and Bridgestoneās on lol) ā¦ unless it already had good ones on it alreadyā¦
Do not mix RFT and non RFT tires, they handle different due to the very thick sidewalls and can be dangerous, plus if your tpms light comes on you wonāt know if it is safe to drive or notā¦
A good RFT will handle almost as good as a fully inflated tire, so very safe to drive on as long as you donāt go to fast or to longā¦ You can drill 1/2" holes in the side of all 4 Bridgestone DriveGuards and not really notice the difference under normal drivingā¦ They also ride just like if not better then a regular tireā¦ I have never had a customer complaint on a DriveGuardā¦ So you get the smooth ride of a non RFT but get the RFT technologyā¦
But as already stated, if not going RFT, make sure to not only get a spare but also the jack and anything needed to change a flat tireā¦ And make sure you keep metal tools away from the battery in the trunk (most BMWs now)ā¦
Not all dealers have their own alignment equipment and those who do have the same equipment that is used by tire dealers and independent mechanics. The factory uses rolling alignment equipment, not practicable for a shop.
The key to any alignment is that the equipment is periodically checked for calibration. Ask to see any documentation they have on calibration.
Next, ask about the technicians training and qualifications.
@lion9car , the short answer is yes. I have never had a pothole knock any of my vehicles out of alignment. I hit a LOT of potholes.