So you're leafing through the newspaper on a lazy Sunday afternoon, and you come across a classified ad that reads something like this:

• GREAT TIRES FOR SALE! Barely used, premium tires, $15 each. Come to Josie's Bar and Grill, ask for Snake. NO COPS.

Now you know that you are going to land in hot water if you answer that ad because receiving stolen goods is against the law. But buying used tires legally may lead to almost as much trouble.

Note that I said "may" rather than "definitely would." This is because you may have found what is legitimately a great deal. But when buying anything it is important to bear in mind the words "caveat emptor." For those who escaped the classics in school, this essentially means "Let the buyer beware." This adage applies in every case where you are being asked to shell out hard earned money, but it especially applies when buying anything that is used.

It should also be noted that references in this article apply only to buying used tires, not retreads. Retreads have their own pros and cons, and will be dealt with in a separate article.

Part of the problem with buying used tires is that it can be difficult to tell the difference between a tire with lots of wear left in it and one that is less than a year away from biting the dust.

If you are dead set on buying used tires, there are some questions you should ask the seller, and some questions you should ask yourself. The first question could be considered almost a no-brainer, but it is one a surprising number of people fail to ask when purchasing used tires, used cars, etc. Ask why they are selling the tires rather than using them. If there isn't a good answer for this, get out fast! Also ask where they got the tires. A cagey or vague response could mean that they were purchased used to begin with, or that it was so long ago the seller doesn't remember.

If possible, take a couple of minutes to look over the seller's vehicle. If the vehicle is obviously poorly maintained, then chances are the tires weren't maintained either.

Basically there are two things to bear in mind when considering used tires. One, you don't know exactly what you're getting. Even if the tire looks great it may have hidden problems. Two, there is no warranty. You'll be stuck with what you get.

Buying used tires can result in big savings, but it can also result in big problems. In any case, remember: Buyer beware.