What is the difference between P-metric and metric tires?

In our forum for calling some of our readers have questioned the interchangeability of the P-metric and metric tire size designations. But the answer to this question is like asking how to solve the national debt crisis. In other words, there are many answers, and some may be more practical decisions than others.

There are two basic size designations are often used for passenger car tyres, called P-metric and metric size. If you see "P" to the size of the tyre sidewall is P-metric tire. If there is no P is metric tyre (also called Euro metric or hard metric). In the past, measures of p are often an indication of the amounts found on domestic cars, vans and light commercial adapters and pikapi. Foreign cars usually came with metric tires. These days, however, you can find P-metric and metric tires for all types.

So that the frequently asked question is: you can use the P-metric and metric tires interchangeably when purchasing tires for replacement?

Even within the industry there are conflicting points of view. For example, let's take a look at the differences between P215/60R16 and 215/60R16 tire. Physically, they have almost the same dimensions and to accommodate interchangeably, but you will notice a difference in the two-and three-digit number after the amount, called the index. The higher the load index, the more freight capacity of the tyre. P215/60R16 has the load index of 94, correspond to the maximum load of 1,477 lbs at 35 psi; 215/60R16 tyre has load index of 95 for a maximum period of 1,521 lbs of 36 psi.

Why the difference? Both types use different load and inflation formulas; as a result, metric tire is a little greater load index and greater capacity for the carriage of cargo reserve of its P-metric socket. (Learn how to decode the size and other data.)

Therefore, if the car is delivered with the P-metric tires, you can change them with the P-metric or metric tires. Metric tires will have greater capacity to load spare from what came out of the car as original equipment and is an acceptable substitute. The number of producers of tyres provide for the substitution.

However, since the P-metric tires have lower load capacity reserve of reward metric, you should not use the P-metric tire size part of the metric tyres on your car as original equipment. Some readers sometimes Forum may argued this point, noting the P-metric to adjust the tyre pressure to ensure equivalent maximum load capacity of metric tire. This is true within certain restrictions, but conversion is best left to the professional tyre trader, who has access to tyre installation guide for proper tire replacement.

As a general best practice is to replace the tyres with the same tag size and load index, which was originally of your car. Questions related to your tyres data can be found on the placard on the door jamb of most cars. Some older vehicles may have a placard in the glove, behind the cover for filling fuel, or on the inside of the truck lid.

Finally not be P-metric and metric tires of the car, could compromise handling, braking and patterns of productivity.

Now for the debt crisis …

– Jean Petersen

View the original article here