I don't know about Car tires but for MC tires it's my experience that about 40% of the time they are out of balance... .now, does that mean it's noticeable? In many cases it's only out by any where from .5 to 1 oz which may not be something you'd ever detect... sometimes they are out quite a bit more.
I recently bought a static balancer so will be getting the tires changed for $10 and then balancing them at home. BTW, here is a test report from SkooterG on the FJR forum who was an adamant anti car tire person until he tried one on his FJR. Read below:
"Well, yesterday I got to do my last test of the car tire - tight twisties. I was faster than I have ever been! I still can't get my head around it. It just makes no sense to me. My favorite set of twisties in Arizona - constant 20mph-30mph curves that I was taking at 35mph to 70mph. The FJR felt totally planted. More than at any other time I have ridden it. More planted led to it feeling 100% rock solid stable which gave me the total confidence to take it to extreme lean angles. I actually scraped pegs 5 times or so. Now, I am not a big peg scaper - I do it occassionally. (Remember I have custom suspension front and rear) But since the car tire actually raises the rear of the FJR I thought I would never scrape with it on there. To scrape now, I have to be leaned over more than I ever have been before. Yet there I was, hitting those lean angles I have never hit before and being totally relaxed. Usually, I feel 'tight' when at extreme lean angles. But not yesterday. Sometimes that has to deal with being 'in the zone' or not, and yesterday I was, but I have NEVER been that relaxed at hitting those extreme lean angles. I just don't get it."
I just changed to a new BT023 front and again can vouch for how much better the CT feels with a new front tire as opposed to a much used one. The old front tire makes more countersteer effort with the CT, so back to good feeling riding again with the Hankook.
JDP