What Is Aspect Ratio In Tires?
The aspect ratio is a number that represents the height of the tire’s sidewall as a percentage of its width. It’s an integral part of the tire size designation, usually written as a two or three-digit number followed by a slash and another number. For instance, in the tire size “205/55R16”, the aspect ratio is 55, indicating that the height of the tire’s sidewall is 55% of its width.
Decoding the Aspect Ratio
The tire size “205/55R16” can be broken down into three parts:
- 205: This is the tire’s width in millimeters.
- 55: This is the aspect ratio.
- R16: The “R” denotes a radial tire, and “16” is the diameter of the wheel in inches.
Implications of Tire Aspect Ratio on Vehicle’s Performance:
Lower aspect ratios (e.g., 30 or 40) usually mean the tire has a shorter sidewall, which often results in better handling and stability, especially during cornering at higher speeds.
Higher aspect ratios (e.g., 65 or 75) signify a taller sidewall, which can absorb more road imperfections and offer a smoother, more comfortable ride.
Generally, tires with higher aspect ratios tend to exhibit lower rolling resistance, which may lead to reduced fuel consumption. However, various other elements like tire tread design and rubber compounds also significantly contribute to fuel efficiency.
What Is the Most Common Tire Aspect Ratio?
The most common tire aspect ratios are typically between 55 and 65.
How Tall Is a Tire With An Aspect Ratio of 70?
If a tire has an aspect ratio of 70, the height of the tire is 70% of its width. For example, if the width of the tire is 200 millimeters, the height of the tire would be 140 millimeters (200 mm x 0.70).
Is a Higher Tire Aspect Ratio Better?
A higher tire aspect ratio generally leads to a taller sidewall. It provides a smoother and more comfortable ride as it can better absorb road imperfections. However, it may offer less precise handling, especially in corners compared to tires with a lower aspect ratio.
A tire with a lower aspect ratio is more responsive to lateral forces compared to one with a higher aspect ratio. It enhances steering stability and overall handling characteristics. Essentially, a shorter sidewall or lower aspect ratio allows for faster transmission of steering input from the wheel to the tread.
Moreover, the aspect ratio influences the tread contact patch, with low-profile tires generally offering a wider patch. This broader contact patch yields a stiffer footprint, minimizing distortion and enhancing cornering traction.
It is important to have a balanced aspect ratio if you want a tire for your family vehicles. For performance vehicles, sports cars, and racing cars, lower aspect ratio tires are generally preferred.