JKB Tire Co Frequently Asked Questions

The Tire Pressure Monitoring System (TMPS) is an electronic system in your vehicle that monitors your tire air pressure and alerts you when it falls dangerously low. This system alerts you with a tire pressure light on your dashboard when a tire needs inflation. It will not alert you if your tires are overinflated. 

To help drivers recognize the importance of tire pressure safety and maintenance, Congress passed the TREAD act, which requires most vehicles made after 2006 to be TPMS equipped. If your tires constantly need re-inflation, consider visiting us for new tires.

A tire’s speed rating indicates the speed category — or range of speeds — at which the tire can carry a load under specified service conditions. The speed rating system used today with new tires was developed in Europe in response to the need to control the safe performance of tires at standardized speeds. 

A letter from A to Z symbolizes a tire’s certified speed rating, ranging from 5 km/h (3mph) to above 300 km/h (186 mph). This rating system, which is listed below, describes the top speed for which a tire is certified. It does not indicate the total performance capability of a tire. 

When this speed rating system originally was developed, the Unlimited V category of over 210 km/h (130 mph) was the top speed rating a tire could achieve. As manufacturers made more tires that did not fit this category, it was necessary to better regulate performance at standardized speeds to ensure safety. The Limited V category of 250 km/h (149 mph) was then created, and the Z speed rating was added as the top speed rating that a tire could achieve. W and Y limited speed symbols have been added as higher speed categories. Always consult the manufacturer for the maximum speed of Unlimited Z tires. 

A speed rating is identified as a part of the tire’s sizing or service description. In the latest attempt to standardize tire designations, all ratings except Unlimited ZR incorporate the speed symbol and load index as the tire’s service description. For example:

205/60R15 91V. 205 = Section Width in Millimeters. 60 = Aspect Ration R = Radial Construction. 15 = Rim diameter in Inches. 91 = Load Index Service Description. V = Speed symbol. 

When "ZR" appears in the size designation with the service description, the maximum speed is as indicated by the service description. For example:

Tire Designation

Maximum Speed P275/40ZR17 93W

270 km/h (168 mph) 

P275/40ZR17 93Y

300 km/h (186 mph) 

For tires having a maximum speed capability above 240 km/h (149 mph), a "ZR" may appear in the size designation. For tires having a maximum speed capability above 300 km/h (186 mph), a "ZR" must appear in the size designation. Consult the tire manufacturer for maximum speed when there is no service description.

Premature tire wear may be caused by many factors other than tire rotation. Reasons could include improper inflation, driving conditions, misaligned vehicles, worn vehicle parts, and a variety of other reasons. Without physically inspecting the tires, it is difficult to make a determination as to why your new tires wore prematurely. Please visit us today and have one of our trained professionals inspect your tires free of charge.

According to Consumer Reports, rotating your tires is essential and most tire manufacturers suggest a rotation interval of every 5,000 to 8,000 miles. An important maintenance service, regular tire rotation will extend the life of your new tires. Along with rotation, proper tire inflation is also necessary for extending performance and tread life. Your auto service professional will examine the tread to determine the best tire positioning to promote even wear. The type of vehicle, such as a front-wheel drive or a 4-wheel drive, may also determine the best tire rotation pattern. Some manufacturers have specific recommendations for a particular vehicle or tire, so always refer to your owner’s manual tire rotation guidelines to ensure proper tread wear.

While wheel balancing and wheel alignment are commonly confused, the two are separate and necessary services. When the vehicle begins to show certain symptoms of trouble balancing and alignment, it should be inspected. Heavy vibration typically means you have a wheel balance issue. Rapid and uneven tread wear or the vehicle pulling to one side of the road usually means there is an alignment problem. When your car or light truck shows any of these signs, wheel alignment or wheel balance could be the problem. Get an inspection as soon as possible to prevent further tire damage. For more information or to receive new tires, reach out to us today!