What is aspect ratio on a tyre?
Understanding tyre aspect ratio
The aspect ratio is one of the key numbers in your tyre size and has a direct impact on how your car rides and handles.
What it means
The aspect ratio is the second number in a tyre size. It represents the height of the tyre's sidewall as a percentage of the tyre's width. For example, in 205/55 R16, the aspect ratio is 55, meaning the sidewall height is 55 percent of the 205mm width, which works out to about 113mm.
How aspect ratio affects your drive
| Lower aspect ratio (e.g. 35 or 40) | Higher aspect ratio (e.g. 60 or 65) |
|---|
| Shorter, stiffer sidewall |
Taller, more flexible sidewall |
| Sharper steering response |
More cushioned and comfortable ride |
| Better cornering grip and precision |
Better absorption of potholes and bumps |
| Firmer ride quality |
Softer ride quality |
| More vulnerable to pothole damage |
Better protection for alloy wheels |
Which should I choose?
In most cases, stick with the aspect ratio specified for your vehicle. If your car offers multiple wheel size options, a larger wheel diameter typically means a lower aspect ratio for sportier handling, while a smaller wheel with a higher aspect ratio prioritises comfort. Either way, stay within the manufacturer's approved sizes.
