5. Don't rely on the TPMS. If your vehicle was manufactured in 2008 or later, chances are it has a Tire Pressure Monitoring System, which warns when tires are underinflated. Insufficient air pressure not only is a safety hazard but speeds tire wear.
So at any given time, why do a majority of cars have at least one underinflated tire? "Most people never check their tire pressure," says Mark Cook of the Tire Industry Association, and the pressure monitoring system gives a warning only when tires are underinflated by 25 percent or more, not lesser amounts that still affect tread wear and tire lifespan.
To make your tires last longer, take five minutes every month to ensure that they're inflated according to specs listed on the car's door jamb. What's noted on the tires themselves is the maximum allowable pressure, not the pressure you want.
This isn't to say that a pressure monitoring system isn't worth keeping in good working order. Keep in mind that its brains are in special tire valves. They cost about $50 each and should be replaced every three to five years, says Cook.
6. Know how and where to bargain. Tires are expensive but can you dicker for a discount? You certainly should try, but good luck.
Your auto dealer or neighborhood garage will likely offer zero or very low discounts, claiming thin profit margins.
Because of their buying power, warehouse clubs such as Costco and BJ's sell many tires for less. But aside from coupon sales, don't expect to successfully bargain down here. Sales clerks at chains that specialize in tires tend to work on commission, so they may have more wiggle room or will make "match any price" offers.
Websites that sell tires (for shipment to local installers) are worth checking out too. Type "buy tires online" into a search engine to find these sites.
Overall, you'll fare best seeking a discount not on the tire, but on related services such as installation, lifetime tire rotations or oil change. Expect salesmen (who sometimes must meet sales quotas) to push for more expensive tack-ons such as brake jobs and alignments. If your car needs them, ask for a discount on them as part of your tire purchase.
Sid Kirchheimer writes about consumer issues.