What Everybody Ought to Know About Tires

Tire Image


245/40R18 82V


Let’s be honest, tires can be confusing sometimes. What the heck do all those numbers mean on the side of the tire? How do I know I’m getting the right tire for my car? Why are all of these things important to know? Do I even need tires on my car? (yes) What is the meaning of life? Let’s clear the air here and do a little learning.


The numbers on the tire
Refer back to the tire mentioned above. 245/40R18 82V. Let’s break it down.

245 – This is the width of the tire in millimeters.

40 – This is the aspect ratio of the tire. Plain and simple, this is the ratio of tire width to tire height. The higher the number, the taller the sidewall, the lower the number, the lower the sidewall. The 40 indicates that the sidewall is 40% of the tire width.

R – Refers to Radial Construction. 98% of tires sold today are radials; chances are you’ll never see a different letter (except for possibly a spare tire).

18 – The size of the rim the tire will go on.

82V – This is the Service Description and is made up of the Load Index and Speed Rating.

82 – Load index. Tires are assigned a number from 0-279 that corresponds to how much weight the tire can handle at maximum inflation. 82 is rated at 1,047 pounds.

V – Speed Rating. All tires are assigned a letter that indicates the maximum speed capability of the tire at proper inflation. The most common tires are rated S with a top speed of 112mph or T (118 mph). Tires for high performance vehicles have a rating of V (149 mph) and go up to Z (186 mph).


Other important tire information
For goodness sake, keep your tires properly inflated. Why? Three reasons. Properly inflated tires are safer (better traction keeps you on the road and not a ditch), they help to keep tire tread to wear evenly (your tires last longer), and better fuel economy (gas is expensive!). All of these will help you save money, your car, and your life (both yours and your tires).

These are the basics when it comes to tires. Sure there is a lot more information about tires, but for most of us, this will suffice when it comes to making a tire purchase.

Ready to buy new tires? Schedule your service at our Cincinnati Auto Repair department.


About Jeff Cryder Jr.