Tires: tire vibration, tire vibration, wheel balancing

Question
I just purchased 4 new tires and had them balanced and mounted. While driving at 65-70mph I can feel a vibration through the steering wheel. It is a slight vibration and definitely not a shake. Could this be caused do to misalignment, or is this a wheel balancing issue? Will a new alignment fix this? The car is a Subaru with all-wheel drive.  

Answer
David,

Alignment can cause tires to wear in an irregular manner, which can result in noise and / or vibrations.  But it takes some time for wear to take place, so alignment is not causing the problem, nor will it be fixed with an alignment.

Don't get me wrong, I think alignments ought to be part of the new tire regimen, if it is expected that tires should do what tires are supposed to do.

There are several possible problems here:

First is the balance.  I have had considerable problems getting consistent readings from balance machines - to the point where I believe the average tire buster can't get a good balance 50% of the time.

The second is a tire property called force variation.  Unlike balance, which is a mass distribution problem, force variation is a stiffness distribution problem.  Some folks call this "out of round", but that's not quite true.

There are a bunch of other possibilities, but at this point it would be smart to take the vehicle back to the tire dealer and get them to take a look.

BTW, Since you feel the vibration in the steering wheel, it is probably the front tires.  Be sure to pass that info on to the dealer.

Hope this helps.