Q. I understand there's a government tire-grading system now similar to the one they have for automobile gasoline mileage. The higher the grading number, the longer your tire is supposed to last. Is this grading system an accurate guide for consumers to follow?

A. The tire-grading system is based on government test standards, but individual tire companies "interpret" the results in their own way. The government doesn't test the tires and grade them -- the tire companies do it.

So you have a grading system that has become a borderline farce. Some companies take the top limit of the government test track results and other companies take more conservative (read: more realistic) limits.

The government test track area is in San Angelo, Tex., and the actual tests go easy on the tires in comparison with what normal daily driving would be.

One government official said that consumers might realistically expect about 60 percent of the mileage tires get on the government test track.

It's sort of like the EPA gas mileage ratings for cars. If a car is rated at 26 miles per gallon, very few motorists will actually get mileage performance that good.

But there's a big difference between the tire tests and the EPA mileage tests. For tires, the companies do their own testing and interpretations. For gas mileage, the government does the testing.

Basically, you have companies that have rated their tires conservatively versus those that rate them boldly. The most conservative is Michelin, which rated its top tire at 140 (equals around 40,000 miles tread wear). Goodyear, Firestone, General and B.F. Goodrich, rated theirs at 170 (around 44,000 miles).

Then the bold ones, such as Uniroyal, Bridgestone (Japanese) and Kelly Springfield, rated theirs at 220 (66,000 miles). Some major manufacturers, making tires for other, private brand company names, also have rated tires at 220. Among these: Avalon (made by a Goodyear subsidiary), Formula Brand (made by Armstrong), Saxonite (Goodyear) and Sears Roadhandler (Armstrong). Few, if any, motorists will ever get 66,000 miles on these tires. Your best bet is to pick the best brand tire you can get at the best price and hope the dealer will steer you straight on overall quality. The grading system, as it is now being used by the tire companies, won't be of much help.

Q. I took the bus to Florida and the company lost one of my bags. It probably happened at a transfer terminal. As I was going to stay south for several months, I had packed a number of vaulable belongings. When I presented the company with a bill for $462, I was told that the legal liability was only $250. Don't they have to replace my things when it was clearly their fault?

A. No they don't. It's true that interstate bus lines have a liability of $250 per passenger for baggage. Amtrak has a $500 limit, and the airlines have a $750 limit.

You might consider taking your case to small claims court. First write the bus company a formal letter stating what happened, dates, ticket numbers -- the works. List the items you had in your bag and their fair market value. Demand payment.

If nothing happens, file suit in small claims court and use your letter as a summary of your case for the judge. Small claims court is inexpensive, and you don't need a lawyer.