Tire Talk: Clarifications Of Three Common Terms

Once upon a time, an automotive tire was just an automotive tire. These days, however, tires come with a wealth of different design features and specifications. If your car is in need of new tires, but you're feeling a little nervous about all of the technical lingo involved, read on. This article will teach you what you need to know about three common terms used to describe automotive tires.

Maximum Load

Maximum load is a relatively straightforward term--at least on the outside. This number designates the total weight limit of the vehicle, given the tire's standard inflation pressure. The inflation pressure used to calculate maximum load depends on the load range of a particular vehicle. Light and standard load cars have their maximum load determined for a psi of 35, whereas extra load cars have their maximum load set at 41 psi.

P-Metric vs Euro-Metric

There are two principal designations used where a tire's size is concerned: Euro-metric and P-metric. You can distinguish which type of tire your car is equipped with by taking a look at the string of seemingly random letters and numbers on its sidewall. If that series starts with the letter P, then you have P-metric tires. If there is no P, then your tires are Euro-metric.

Once upon a time, domestically produced cars all contained P-metric tires, whereas foreign automobiles contained Euro-metric ones. Today, however, the boundary is not so clear, and it is possible to find either type of tire on cars produced in any given country. The differences between these two types of tires are subtle--yet sometimes important. 

While it may be possible to interchange P-metric and Euro-metric tires, it is a better idea to stick with the type of tire previously installed on your car. That's because, generally speaking, the maximum load of P-metric tires is somewhat lower than the Euro-metric equivalent. To avoid unintended problems, always allow a professional tire dealer to determine whether it is safe to install tires of a different kind. In no case should your car be equipped with a combination of P-metric and Euro-metric tires.

Tread Depth

Tread depth refers to the vertical distance between the outside of your tire's rubber to the bottom of the deepest treads. In general, the deeper the tread depth, the longer the lifespan of the tire. Measuring remaining tread depth is a common way to establish whether a tire is ready to be replaced. In the U.S., tread depth is commonly expressed in 32nds of an inch. Tires with 2/32" or less of tread depth are considered legally worn out.

Head over to a tire shop like Discount Tire Centers if you are in need of new tires.