6. One sign of low tire pressure is if your tires squeal when cornering.
7. A tire can lose up to half of its air pressure and not appear to be flat.
8. Under inflation is the leading cause of tire failure. It results in unnecessary tire stress, irregular wear, loss of control and accidents.
9. Tire manufacturers (not the U.S. government) test tires and assign their own grades for tread wear, traction, and temperature resistance. However, there is no prescribed formula for converting the manufacturers' test results into universal grades, so be aware of the fact that numbers from tire to tire are not objective.
10. Tires lose air at a rate of about a pound a month, which means if they weren't checked since the last time you had the vehicle serviced (say 4 months ago), they could be several pounds low.
11. Under inflation, by as little as 6 psi, can cut gas mileage by 3%.
12. Cold temperatures affect the air pressure in your tires. There is a loss of one pound for each ten degrees of temperature drop.
13. Warning: Never buy a tire with a lower load index or speed rating than your vehicle's original tire!
14. In North America, regulations require tire manufacturers to grade passenger car tires based on tread wear, traction, and temperature resistance. Tread wear is based on the wear rate of the tire. A wear rating of 300 to 400 is considered good; 500 to 700 is very good. Further, a tire graded 200 would wear twice as long as one graded 100. Traction grades (from highest to lowest: AA, A, B, and C) represent the tire's ability to stop on wet pavement. Temperature grades (from highest to lowest: A, B, and C) represent the tire's resistance to the generation of heat.
15. Gas mileage decreases 1% for each 10 lbs. of under inflation.
16. If you're only buying one or two tires at a time, always put the new tires on the rear axle. It's a myth that putting the new tires on your drive-wheel position will give you the most protection; instead, doing so will make your vehicle more susceptible to over steer (fishtailing or swinging out during fast cornering).
17. Under-inflated tires wear more on the outside edges. Over-inflated tires wear excessively in the center of the tread.
18. Use a penny to determine if the tread on your tires is too low. Take a penny and put Abe's head into one of the grooves of the tread. If a part of his head is covered by the tread, you're ok. If you can see all of Abe's head, it's time to replace the tire. When the tread is worn down to 1/16 of an inch, tires must be replaced.
19. Most manufacturers put "P" (passenger car) rated tires on 4WD trucks as well. Some put "LT" (light truck) tires on SUVs and four-wheel drive trucks, but most do not.
20. The "T" on your tire's sidewall does not stand for Truck: it stands for "temporary" spare.
21. The "recommended" tire pressure is almost always lower than the "maximum" tire pressure printed on the tire's sidewall. Check your owner's manual to find out where to look on your vehicle for the recommended amount of air (usually on the driver's door, the glove compartment, or the gas filler door).
22. Since tires can harden and crack with age, you should steer clear of old tires and buy the freshest ones available. Here's how to tell: Every tire carries a U.S. Dept. of Transportation serial number on the sidewall (EX: DOT M6 RV T1HR 499). The last 3 digits are a date code indicating the week and year the tire was made. (EX: the 49th week of 1999).
[l]Most punctures, nail holes or cuts up to 1/4 inch and confined to the tread may be satisfactorily repaired by trained personnel using industry-approved methods.
23. For the most accurate reading, tire pressure must be checked when tires are cold. You can check tire pressure any time of the day, as long as the tires have been sitting for a few hours or haven’t been driven for more than a few miles.
24. Under normal loads, you should inflate tires according to the vehicle manufacturer's recommendations, NOT the maximum pressure listed on
Used Tires can be an affordable alternative to buying brand new tires. We stock many tires that came from great low mileage vehicles. In many cases, our tires are barely driven on. Try us next time you need a new set of tires or if you just need to replace one. G&R also carries spare tires for that emergency.
Here are some little-known facts about tires, specifically pertaining to general highway tires for your daily driver:
1. Underinflated tires cause the engine to work harder. It's like riding a bike with low tires. It's harder to pedal because of the increased rolling resistance.
2. Should you rotate side to side or front to back? Radial tires can be crossed from side to side in the rotation pattern. Bias ply tires should never be rotated from side to side, but only front to back.
3. Not all SUV's come with "P" (passenger) rated tires. Some have the "LT" (light truck) designation.
4. Underinflated tires wear faster, and they affect the steering and handling of your vehicle.
5. If tire pressure is too low, then too much of the tire's surface area touches the ground, which increases friction between the road and the tire. Thus, your tires wear out earlier, and they could also overheat.
Learn more about used tires