Tire Size 275/65r18 vs 275/70r18
Are you considering switching from 275/65R18 to 275/70R18 tires? While these tire sizes may seem similar, there are some key differences to consider before making the change.
- Diameter increases by 1.08 inches giving more ground clearance
- Sidewall height grows 0.54 inches potentially improving ride comfort
- Tire circumference expands by 3.4 inches affecting speedometer accuracy
- Revolutions per mile decrease by 20.53 possibly impacting fuel efficiency
- Width remains unchanged at 10.83 inches maintaining similar traction
On-Road Impact
Changing your tires can affect your daily driving experience. Here’s how the switch to 275/70R18 tires might impact your on-road performance:
- Ride Comfort: The taller sidewall of the 275/70R18 tire (7.58 inches vs. 7.04 inches) may provide a slightly smoother ride, especially over rough roads or potholes. This extra cushioning can absorb more road imperfections.
- Speedometer Accuracy: Your speedometer will be affected by the larger tire diameter. At a speedometer reading of 20 mph, your actual speed will be about 20.68 mph. This difference increases at higher speeds, potentially leading to unintended speeding.
- Gas Mileage: The larger tires may slightly decrease your fuel efficiency due to increased rolling resistance and weight. However, the 3.4% difference is unlikely to cause a significant impact on your overall fuel economy.
- Handling: You might notice a small decrease in handling responsiveness due to the taller sidewall. This could result in a slightly less precise steering feel, especially during quick maneuvers or cornering.
Off-Road Impact
For those who enjoy off-road adventures, the tire switch can bring some benefits:
- Ground Clearance: The 1.08-inch increase in tire diameter translates to about 0.54 inches of additional ground clearance. This can be beneficial when navigating over rocks, logs, or uneven terrain.
- Traction: The larger contact patch of the 275/70R18 tires may provide improved traction in off-road conditions, especially in mud or loose soil.
- Durability: The taller sidewall can offer better protection against punctures and sidewall damage when driving over rough terrain or obstacles.
Other Considerations
- Aesthetics: The larger tires will give your vehicle a slightly more aggressive look, filling out the wheel wells more completely.
- Durability & Wear: The 275/70R18 tires have a larger circumference (104.17 inches vs. 100.77 inches), which means they complete fewer revolutions per mile. This could potentially lead to slightly slower wear over time.
- Vehicle Systems: Some vehicle systems, like anti-lock brakes (ABS) and traction control, may be calibrated based on the original tire size. The change might affect their performance, though usually not significantly.
What is the Difference Between 275/65R18 and 275/70R18?
The main difference between 275/65R18 and 275/70R18 tires lies in their sidewall height. The 275/70R18 tire has a taller sidewall, which increases the overall diameter of the tire by 1.08 inches (27.5 mm) or 3.4% compared to the 275/65R18 tire.
This difference in sidewall height also results in a 0.54-inch (13.75 mm) or 7.7% increase in sidewall height for the 275/70R18 tire.
Can I Use 275/70R18 Instead of 275/65R18?
It is generally not recommended to use 275/70R18 tires instead of 275/65R18 tires without making necessary adaptations.
The diameter difference between these two tire sizes exceeds the acceptable 3% range, which can lead to potential issues such as rubbing or clearance problems.
If you still wish to make the switch, it’s essential to consult with a professional to ensure proper fitment and to make any required modifications to your vehicle.
How Much Taller Is a 275/70R18 Tire Than a 275/65R18?
A 275/70R18 tire is 1.08 inches (27.5 mm) taller than a 275/65R18 tire. This difference in height is due to the increased sidewall height of the 275/70R18 tire, which is 0.54 inches (13.75 mm) or 7.7% taller than the sidewall of the 275/65R18 tire.
The overall diameter of the 275/70R18 tire is 33.16 inches (842.2 mm), while the 275/65R18 tire has a diameter of 32.07 inches (814.7 mm).
275/65r18 vs 275/70r18 Table
This comparison helps visualize the size differences between the 275/65R18 and 275/70R18 tires, with notable distinctions.
| Feature | 275/65R18 | 275/70R18 | Difference |
|---|---|---|---|
| Diameter inches (mm) | 32.07 (814.7) | 33.16 (842.2) | 1.08 (27.5) +3.4% |
| Width inches (mm) | 10.83 (275) | 10.83 (275) | 0 (0) 0% |
| Circumference inches (mm) | 100.77 (2559.46) | 104.17 (2645.85) | 3.4 (86.39) +3.4% |
| Sidewall Height inches (mm) | 7.04 (178.75) | 7.58 (192.5) | 0.54 (13.75) +7.7% |
| Revolutions per mile (km) | 628.78 (390.71) | 608.25 (377.95) | -20.53 (-12.76) -3.3% |
| Speedo Reading | 20 mph | 20.68 mph | +0.68 mph |
Our Observation
Switching from 275/65R18 to 275/70R18 tires offers a mix of benefits and drawbacks. The increased ground clearance and potentially smoother ride are notable advantages, especially for off-road enthusiasts.
However, the slight impact on speedometer accuracy and possible effects on handling should be considered for on-road use.
While the 3.4% size difference exceeds the recommended 3% limit, the real-world impacts are relatively minor for most drivers. Off-road performance sees more noticeable improvements, while on-road changes are subtle.
Overall, this switch can be a viable option for those seeking a bit more off-road capability without drastically altering their vehicle’s on-road behavior.
Sabrina Khan Tisha, a lead writer at Tiresizecompare.com, brings a wealth of experience to her role. As the CEO of amarcalculator.com, she oversees a platform offering diverse calculation tools. Sabrina’s background in HR and office management, coupled with her numerous certifications, informs her approach to content creation. Her leadership and expertise contribute significantly to the automotive and calculation sectors.
