Tire Size 245/70r17 vs 245/75r17
Thinking about upgrading your tires? Switching from 245/70r17 to 245/75r17 may seem straightforward, but it’s important to understand how it affects your vehicle.
- The 245/75R17 provides a larger diameter for improved ground clearance.
- A taller sidewall height enhances comfort on rough roads.
- The increased circumference may improve stability during highway driving.
- Fuel efficiency might decrease due to the larger tire size.
- The same width maintains consistent handling characteristics.
- The taller tire can enhance off-road capability and traction.
Fitment Guide
According to the Fitment Guide, replacement tires should be within 3% of the original diameter. The 245/75r17 exceeds this limit by 0.2%, reaching 3.2%.
Therefore, the interchange is not recommended without necessary adaptations to prevent issues like rubbing or clearance problems.
On-Road Impact
Switching tire sizes can significantly affect your vehicle’s behavior on paved roads. Here’s how the change impacts on-road performance.
- Ground Clearance: The larger diameter increases ground clearance by about 0.48 inches (12.25 mm). This helps you navigate speed bumps and rough roads more easily.
- Gas Mileage: Slightly larger tires can cause your engine to work harder, potentially leading to a minor decrease in fuel efficiency.
- Aesthetic Look: Taller tires give your vehicle a more rugged appearance, which some drivers find appealing.
- Ride Comfort: The increased sidewall height (a 7.1% increase) provides more cushioning, possibly improving ride comfort over bumps and potholes.
- Speedometer Accuracy: With the larger tire circumference, your speedometer will read lower than your actual speed. When it shows 20 mph, you’re actually traveling at 20.63 mph.
- Durability & Wear: The new tire size may have different wear characteristics, potentially affecting tire longevity.
Off-Road Impact
The tire change also affects how your vehicle performs off the beaten path. Here’s what to expect when off-roading with the new size.
- Ground Clearance: Increased ground clearance aids in navigating obstacles like rocks and logs, enhancing off-road capability.
- Traction: The same tire width means traction remains similar, but the larger diameter helps roll over uneven terrain more effectively.
- Clearance Issues: Exceeding the recommended diameter limit may cause the tires to rub against wheel wells or suspension components during extreme articulation.
- Vehicle Stress: Larger tires can put additional stress on suspension and drivetrain components, possibly requiring upgrades for optimal performance.
245/70r17 vs 245/75r17
This table compares the key features of tire sizes 245/70R17 and 245/75R17.
| Feature | 245/70R17 | 245/75R17 | Difference |
|---|---|---|---|
| Diameter inches (mm) | 30.5 (774.8) | 31.47 (799.3) | 0.96 (24.5) 3.2% |
| Width inches (mm) | 9.65 (245) | 9.65 (245) | 0 (0) 0% |
| Circumference inches (mm) | 95.83 (2434.11) | 98.86 (2511.08) | 3.03 (76.97) 3.2% |
| Sidewall Height inches (mm) | 6.75 (171.5) | 7.23 (183.75) | 0.48 (12.25) 7.1% |
| Revolutions per mile (km) | 661.16 (410.83) | 640.9 (398.24) | -20.27 (-12.59) -3.1% |
| Speedo Reading | 20 mph (32.19 km/h) | 20.63 mph (33.2 km/h) | +0.63 mph |
Difference Between 245/70R17 and 245/75R17
The main difference is diameter; the 245/75R17 tire is 0.96 inches (24.5 mm) taller than the 245/70R17 tire, affecting ride height and speedometer accuracy.
Can I Use 245/75R17 Instead of 245/70R17?
It’s not recommended, as the 245/75R17 tire is 3.2% larger in diameter, exceeding the advised maximum difference of 3%. This may impact handling, braking, and speedometer readings.
How Much Taller Is a 245/75R17 Tire Than a 245/70R17?
The 245/75R17 tire is 0.96 inches (24.5 mm) taller than the 245/70R17 tire, a 3.2% increase in overall diameter.
Our Observation
Switching from 245/70r17 to 245/75r17 offers both advantages and drawbacks. The increased diameter provides slightly higher ground clearance, which is beneficial for off-road driving and overcoming obstacles.
The taller sidewall may improve ride comfort by absorbing more road vibrations. However, the 3.2% increase in diameter exceeds the recommended limit, potentially causing speedometer inaccuracies and minor changes in handling dynamics.
On-road, the effects are generally minimal and may go unnoticed by many drivers. The speedometer reading will be off by about 3%, showing 20 mph when you’re actually going 20.63 mph.
Off-road, the benefits of extra clearance are more pronounced, but the risk of rubbing or clearance issues increases without proper adjustments.
It’s essential to consider these factors and possibly consult a professional before making the switch. Overall, the differences are modest but should be carefully weighed before making the change.
Asma Akter is the lead writer at Tiresizecompare.com, bringing her expertise to the automotive industry. With a strong background in technical writing and a passion for clear communication, Asma excels at breaking down complex tire-related information for readers. Her work helps consumers make informed decisions about tire sizes and compatibility, contributing to safer and more efficient vehicle operations.
