Tires 101


Are your tires set at the optimum inflation? Chances are they are anywhere from 8psi to 18psi less than recommended. The most common way of damaging tires is improper inflation. Low air pressure causes tires to experience irregular treadwear as well as poor vehicle handling and traction. Under inflated tires can build up excessive heat and blow out without warning.

Keeping your tires set at the manufacturer's recommended pressure is one of the easiest ways of saving gasoline, increasing tire treadlife, and ensuring safety. An Arizona Energy Office Report notes if your tires are inflated to 24psi, and you increase the air pressure to 32psi, your fuel mileage should increase by 3 miles per gallon (an average increase of 10%!)

Always check your air pressure and make adjustments when the tires are cold (tires have not been driven for 2 hours). Air pressure should be checked bi-weekly at the very least. This is important because as outside temperatures change, so does tire air pressure. A 10 degree drop in temperature can reduce tire pressure by 1psi. That means if you set your pressures in the July and don't check them again until December, you could have lost several psi, decreasing fuel mileage and causing pre-mature tire wear. Also remember to check your spare tire for loss of air.

tire pressure monitoring system (TPMS):

TPMS involves the use of pressure sensors attached to each tire and wheel assembly which measure the tire pressure and transmit the data through low frequency signals to the vehicle’s computer system. This information is displayed on the vehicle’s instrument cluster usually in the form of a simple pictogram (low pressure warning light) or readings for each tire. There are two types of TPMS sensors – Banded sensors and Valve Sensors. Banded sensors attach to the barrel of the rim by a metallic strap. Valve sensors attach to the rim just like a regular valve stem would, either rubber or aluminum.


When you have a good thing, you want it to last. To extend the life of your tires, they should be rotated every 6,000—8,000 miles. If you have any unusual tire wear, performance, or ride quality, please bring your car in to Ace Automotive and let us check it out.

A vibration when driving could be an indication there is a problem with the balancing of your tires. Especially if you feel a vibration that is dependent on vehicle speed and first becomes apparent between 40 and 45 mph. Your tires being out of balance not only hurts the drivability of the vehicle but can also cause additional issues that could lead to costly repairs.


The speed rating of any tire is a measurement of the top safe speed the tire can carry a load under specified conditions. It is also an indication of how the tire will handle at lower speeds. A higher rated tire will give you better traction and improved steering response – even at 50mph. You will find this rating on the sidewall of your tire, as part of the tire sizing number. Speed ratings are shown with letter designations within the tires size string. They typically will range from Q which is a comfortable 99mph rating to Y which is a blistering 186mph.


The load rating, or load index, is one of the values found on the tire sidewall, as part of the tire sizing designation. The load index indicates the maximum weight that each tire is able to support. You should always replace the tires on your vehicle with a tire that has the same or higher load index than the OEM. This ensures that the tire has an adequate load capacity to carry the weight of the vehicle, cargo and passengers. Never replace the tires on your vehicle with a tire with a lower load index.


Plus sizing your wheel & tire combination was designed to enhance vehicle performance and looks by allowing fitment of larger diameter rims and lower profile tires. The theory is that while making these changes, you keep the overall tire diameter within 3% of the original equipment tires. This is important because larger variances can cause problems with transmission shift points which can decrease fuel mileage. It can also confuse braking system computers which can even lead to brake failure.