New tires are what you need...
I recently rotated the tires on my car and afterward found that my steering wheel vibrated excessively at higher speeds. To test the possibility that the vibration was due to the tires, I switched the two front tires from my wife's car to my car. The vibration disappeared, so I concluded that the problem was my tires. These tires have over 43,000 miles on them, but still look like they're in fair shape. Should I try to have them balanced, or should I buy new ones?
RAY: Well, Luis, the way I see it, you have two options. You can either buy yourself a new set of tires, or you can leave the crumby ones on your wife's car and let HER pay for the new tires.
TOM: Actually, Luis, new tires probably are what you need. Without seeing the old ones, and without knowing why kind of car you have or what kind of driving you do, it's impossible for us to say for certain. But with 43,000 miles on them, chances are they're ready for the junk heap. They may look OK, but my guess is they're not quite round anymore. And as you've discovered, that can lead to serious handling problems at high speed.
RAY: As you've also discovered, bad tires are much more noticeable when you move them to the front wheels, since vibrations in the front are telegraphed right up to your hands through the steering wheel.
TOM: You can try balancing the old tires, Luis, but it probably won't help. My guess is that you'll end up springing for a new set. And when you do, make sure you get all four of your struts checked, and replaced if necessary.
RAY: Bad struts can ruin new tires faster than almost anything else. And besides, buying four struts will make you all but forget about having to pay for a new set of tires. When you see the bill for the struts, the two tires will seem like sales tax.