315/40R21 in Inches
Understanding the dimensions of the 315/40R21 tire size in both metric and imperial units of measurement is an essential part of tire maintenance and replacement. Let us take a closer look at every important aspect of the 315/40R21 tire size to understand what these numbers represent and how they may affect your vehicle's performance.
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What is 315/40R21 in inches?
When we convert 315/40R21 to inches, it is equivalent to 30.9x12.4R21 tire size in the high flotation system.
||406 per km
||653 per mile
How wide is a 315/40R21 tire?
Tire width, also known as section width, is a measurement in millimeters that indicates the width of a tire from one sidewall to the other. It is the first number provided in a tire's size specifications. 315/40R21 tire has a width of 12.4 inches or 315 mm.
A greater tire width can increase the tire's contact patch with the road, potentially improving grip and handling. However, wider tires can also increase rolling resistance, which could negatively impact fuel efficiency.
Tread width: 12.4"
How tall is a 315/40R21 tire?
Tire height, also known as the tire's diameter or overall diameter, is the measurement from the ground to the top of the tire. It's essentially the distance from one side of the tire to the other, passing through the center, when it's correctly inflated and not under load. 315/40R21 tire has a diameter or height of 30.9 inches or 785.4 mm.
Tire height: 30.9"
315/40R21 Tire Sidewall Height
Tire sidewall height, also known as the tire's aspect ratio, is the measurement of the height of the tire's cross-section or the height of the tire from the rim to the tread. It is typically represented as a percentage of the tire's width. 315/40R21 tire has a sidewall height of 5 inches or 126 mm.
Sidewall height (also known as tire profile) can greatly affect a tire's driving characteristics. Lower profile tires (30 or 35 series) often provide better handling but can give a harsher ride, while higher profile tires (65 or 70 series) generally provide a smoother ride but with less precise handling.
Sidewall height: 5"
What size rim fits a 315/40R21 tire?
The rim diameter refers to the diameter of the wheel on which a tire is mounted. It is the distance from one edge of the rim to the opposite edge, passing through the center of the wheel. 315/40R21 tire can be mounted on 21 inch wheels.
The rim diameter is crucial not only for fitting the tire properly but also plays a role in determining the overall performance of the vehicle, including its handling and ride quality.
Rim diameter: 21"
315/40R21 Tire Circumference
Tire circumference refers to the distance around the outer edge of a tire. It is the measurement of the entire circumference or perimeter of the tire when it is inflated and mounted on a wheel. 315/40R21 tire has a circumference of 97 inches or 2466 mm.
Tire circumference: 97"
How many revolutions does a 315/40R21 tire make?
Tire revolutions refer to the number of complete rotations a tire makes while the vehicle is in motion. It is a measure of the distance covered by the tire. 315/40R21 tire completes 653 revolutions per mile or 406 revolutions per kilometer.
Tire revolutions are often used in various calculations related to vehicle dynamics, such as determining the distance traveled, estimating fuel consumption, or calculating the speed of the vehicle based on the rotation of the tires. Tire revolutions can also be tracked or monitored by certain vehicle systems, such as the anti-lock braking system (ABS) or the vehicle's onboard computer, for various purposes.
Tire revolutions: 653 per mile
More 21-inch Tire Conversions
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