In our ongoing series of Q&A blog columns, we will highlight common and interesting questions posted to our Car forums, with answers from our automotive experts.

Question: My Mazda RX-8 is showing tread wear on the outer edges of the tire. Wheel balance, right? Wrong. I paid $50 to find out that all the wheels are within specs. I consistently keep the inflation between 32-34 lbs so that can't be it. The shop guy said "bad tires." They are original Bridgestone Potenzas. Could he be right? I don't know where to turn next.

Answer: Tire wear issues like that mentioned above are all too common and often the blame goes to the tire manufacturer if there is no apparent easy answer. That’s too bad since it can be avoidable most of the time. Most experienced tire dealers can diagnose the problem just like a doctor does with a patient – mostly by observing and narrowing down the possibilities.

In this case, the tire wear pattern tells the story. The fast outside shoulder wear suggests a wheel mis-alignment. The owner said that the tires received an alignment, which was deemed in-spec but not on-spec. Often that might not be good enough for some cars and the owner and consumers alike should request that wheel alignment be adjusted back to the middle of the alignment specification or as close as possible. In other words, sometimes “close-enough” isn’t good enough. The RX-8 owner isn’t alone. We just recently examined a police cruiser that had a similar wear problem. The officer had the cruiser checked for alignment and was told it was within tolerance but not to the exact specification. Ironically, the alignment shop told the officer that the tires were probably the problem and replaced them. Guess what? The new tires were starting to wear like the old ones. We told the officer to have the wheels re-aligned to the exact specification and to have the shop check for any worn suspension components while they were at it.

Bottom line: Sometimes you have to be persistent. The red flag in both examples was that the alignment was checked, but the shop didn’t put the effort into re-aligning the car to the exact specification. Look at your tires, particularly their wear, as they can tell the story.

—Gene Petersen