What Size Are My Tires?

Tire size is given in a sequence of seven numbers, for example:  2 4 5/ 3 5 R1 7. This sequence of numbers can be found printed directly on the sidewall of your tires.

The first set of numbers (245) being the tire width in millimeters, the second set (45) being the ratio (%) of the sidewall to the width of the tire, and the third set (17) being the actual wheel diameter in inches.




How Do I Know What Tires Fit My Vehicle?

The Original Equipment (OE) tire size for your vehicle can be found on your driver side door jamb (“B-Pillar”). Older model vehicles might show this on the glove box lid, gas cap door, engine compartment, or in your owner’s manual.

How Do I Check My Tire Pressure?

Tire pressure is measured in Pounds per Square Inch (PSI). To check your tire pressure you will need a quality air pressure gauge, which can be bought at most automotive parts stores. Depending on the type of gauge you are using, PSI are either represented by notches or by a digital reading of a number. The correct tire pressure for your OE (Original Equipment) tires can be found directly on your driver side doorjamb (“B-Pillar”). The maximum PSI (Pounds Per Square Inch) is printed directly on the sidewall of your tires.

It is recommended to check your tire pressure first thing in the morning, this is when the temperature of your tires is at its most stable. The temperature of your tire is important to an accurate reading. Such factors as direct sunlight or driving your vehicle, even for a short distance, can give you an inaccurate reading of your tires air pressure.

 When Do I Need To Replace My Tires?

By law, all tires sold in North America are equipped with a “tread wear bar”. This bar is a strip that runs along the width of the tire. When the tread of a tire wears to the same point as the wear bar, the tire needs to be replaced.

Try the Penny Trick. Place a penny within the tread of your tire. If Lincolns head is completely visible your tire is at 1/32″, which by law is legally bald.

What Are Tire Pressure Monitoring Systems (TPMS)?

TPMS can be either Direct or Indirect.

Direct Systems use a pressure sensor, attached through the tire valve stem, which alerts your vehicle when the tire pressure is too low. TPMS Sensors vary in brand and part number depending on the make of the vehicle.

Indirect Systems rely on the vehicles antilock braking system to compare the speed of one tires rotation against another (a tire with low tire pressure will spin a different number of times per mile when compared with a tire which is properly inflated.)


Why Can’t I Use Run flat Tires Without A TPMS?

Run flat tires are so well built that a driver might not notice the difference when a tire is underinflated or flat. Without TPMS, a driver may be causing additional tire damage by not properly inflating or repairing the tire as soon as possible (ASAP).

How Do I Know If My Tires Are Directional? Are They Mounted and Rotated Correctly?

Tires that are directional have an indication arrow located on the tire sidewall. This shows which direction the tire will be turning.

Directional tires are meant to be used on only one side of a vehicle and can be rotated from the front to the rear. Unless tires are dismounted and remounted to the wheel they cannot be utilized for the opposite side of the vehicle.

If My Vehicle Originally Came With Run flat Tires, Can I Mount Non-Run flat Tires On My Stock Wheels?

It is possible to mount non-run flat tires on a vehicle which originally came with run flat tires. Just keep in mind that most vehicles, whose factory wheels include run flat tires, usually do not provide a spare tire.

What Is The Correct Speed And Load Rating For My Vehicle?

The speed and load rating for a vehicle are there to indicate the maximum weight capacity and at what speed your tire will be at its maximum capability. This is represented as a number and a letter, for example: 84Y (This information can be found on the tire sidewall) .The 84 being the load rating and the Y being the speed rating. The higher the number, the greater the load capacity for your tires will be. The higher the letter, the greater the speed each tire can sustain.