Car Tires
Commercial Tires
The Roundup – Tire Size, Speed Rating & Load Index
What tire size do you have on your vehicle?
This question generates confusion and stress for new drivers or some of our customers. Not everyone remembers their tire size or knows where to look for that information, and that’s ok! That’s why we’re here; you don’t have to stress and can rely on our expertise.
If you are curious and want to understand the lingo, here are some basic tips on where to find that information on your vehicle and what some of the terms mean.
ASPECT RATIO (RATIO %)
The aspect ratio measures the height of the sidewall as a percentage of the tire width. For example, a tire size 205/65 R16 has an aspect ratio of 65, meaning the sidewall height is 65% of the tire width.
SIZE, SPEED RATING & LOAD INDEX TIRE WIDTH (MILLIMETRES)
Tire width is measured in millimetres from sidewall to sidewall and is shown in the first three-digit number of the tire size. Here, the tire width is 205mm.
RIM DIAMETER (Inches)
Rim diameter refers to the size of the wheel (in inches) measured from edge to edge across the face of the wheel and determines the size of the rim that the tire can be mounted on.
LOAD INDEX (Number)
The tire load index indicates how much weight your car can safely carry based on tire size and pressure. The higher the load index, the more weight the tire can carry.
SPEED RATING (Letter)
A tire’s speed rating indicates the fastest speed it can handle before it no longer performs as designed. Here, V = 240km/h!
Where can I find my tire size?
There are two main places where you can find your tire size;
- On the sidewall of your tire
- On the inside frame of the driver-side door
You can also visit our website and search by vehicle. By selecting the year, make, model and sub-model of your vehicle, our website will provide the tire size included as original equipment on your car.
Still uncertain? Just contact our team, and we will be happy to help!