Tire Size 245/65r17 vs 245/75r17

The 245/75R17 tire has a higher aspect ratio, which means that the sidewall is taller. This will give you a smoother ride and more ground clearance, reducing your top speed and fuel economy.

The 245/65R17 tire has a lower aspect ratio, which means that the sidewall is shorter. This will give you a sportier ride and better handling but also reduce your ground clearance.

245/65r17 vs 245/75r17 Table

This helpful comparison table offers an in-depth analysis of the disparities between tire sizes 245/65r17 and 245/75r17.

Overall Diameter
The diameter is the distance from one end of the tire to the other, passing through the center. In our comparison, the 245/65R17 has a diameter of 29.54 inches (750.3 mm), while the 245/75R17 has a larger diameter of 31.47 inches (799.3 mm), making a difference of 1.93 inches (49 mm) or 6.5%.

The larger diameter of the 245/75R17 can contribute to increased ground clearance, which is beneficial for off-road driving. However, this might lead to the slightly higher center of gravity, potentially compromising vehicle stability.

Section Width
The section width, measured in millimeters, represents the distance across the widest part of a tire’s outer surface. Both the 245/65R17 and 245/75R17 tires have a section width of 9.65 inches (245 mm), meaning there is no difference in the width.

Identical section widths imply that these tires can provide similar traction on straight roads. But, the tire’s performance is also influenced by other factors like tread pattern and rubber compound, not just its width.

Circumference
The tire circumference refers to the distance a tire covers in one complete revolution. Here, the 245/65R17 has a circumference of 92.8 inches (2357.14 mm) compared to 98.86 inches (2511.08 mm) for the 245/75R17, marking a difference of 6.06 inches (153.94 mm) or 6.5%.

The larger circumference of the 245/75R17 means it will cover more ground per revolution, potentially providing a smoother highway ride. However, it might also slightly reduce the vehicle’s acceleration capabilities due to the increased distance it has to travel per tire rotation.

Sidewall Height
The sidewall height, sometimes referred to as the aspect ratio, is the distance from the wheel rim to the top of the tire’s tread. The 245/65R17 has a sidewall height of 6.27 inches (159.25 mm), while the 245/75R17 has a height of 7.23 inches (183.75 mm), a difference of 0.96 inches (24.5 mm) or 15.4%.

Like in the 245/75R17, a larger sidewall height often results in a more comfortable ride as the tire can absorb more road bumps. However, it might also decrease handling and cornering performance due to the higher flex in the sidewall.

Revolutions Per Mile
The revolutions per mile represent the number of times a tire will rotate in one mile. The 245/65R17 tire completes 682.75 revolutions per mile (424.24 per kilometer), and the 245/75R17 completes 640.9 revolutions per mile (398.24 per kilometer), a difference of -41.86 revolutions per mile (-26.01 per kilometer) or -6.1%.

Lower revolutions per mile of the 245/75R17 mean the tire rotates fewer times to cover the same distance, which could result in less tread wear over time. It might also lead to slightly less accurate speedometer readings because the car will be traveling a little further for each revolution than the speedometer expects.

Wheel Size
Both the 245/65R17 and 245/75R17 tire sizes are designed for 17-inch wheels and have a radial (R) construction type, indicating that the internal ply cords are positioned in a radial direction, from one bead over to the other.

Alternative Tire Size of 245/65r17
The maximum difference of 3% in overall diameter is allowed for the replacement tires compared to the original ones.

Alternative Tire Size of 245/75r17
The overall diameter of the replacement tires should not deviate more than 3% from that of the original tires.

Our Observation
When comparing the 245/65R17 and 245/75R17, we can observe that while they share the same section width and are suited for the same wheel size, they exhibit significant differences in diameter, circumference, sidewall height, and revolutions per mile.

The choice between the two would primarily depend on your specific driving needs. The 245/65R17 is more suitable for city and highway driving due to its lower diameter and sidewall height, offering better stability and handling.

On the other hand, for off-road or comfort-oriented driving, the 245/75R17, with its larger diameter and sidewall height, may provide increased ground clearance and a smoother ride.

Remember, changing your tire size should be done in consultation with a tire or automotive professional to ensure safety and compatibility with your vehicle.

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Caitlin McCormack

Meet Caitlin McCormack, a Tire Size Expert and Blogger Passionate About Everything Related to Tires. With Years of Experience in the Tire Industry, Caitlin Has Become an Expert in Tire Sizes and Their Impact on Vehicle Performance.