Tire Size 275/55r20 vs 275/65r20
Upgrading your tires from 275/55R20 to 275/65R20 is like giving your vehicle a growth spurt. This change brings a noticeable increase in height and affects how your vehicle handles various terrains.
- Overall diameter increases by 2.17 inches or 6.8%
- Sidewall height grows by 1.08 inches or 18.2%
- Speedometer will underreport actual speed by about 6.8%
- Revolutions per mile decrease by 40.16 or 6.4%
- Larger tires may slightly reduce fuel efficiency
- Off-road traction and capability generally improve
Fitment Guide
It’s crucial to follow the fitment guide. The 275/65R20 tire exceeds the recommended 3% diameter difference from the original 275/55R20 size.
This means the interchange is not typically recommended without making necessary adaptations to your vehicle to prevent issues like rubbing or inadequate clearance.
On-Road Impact
Switching to larger tires can significantly affect your vehicle’s on-road performance. Here’s how the change from 275/55R20 to 275/65R20 might impact your daily driving experience:
- Gas Mileage: The larger, heavier 275/65R20 tires may decrease fuel efficiency. The extra weight and rolling resistance can make your engine work harder, potentially reducing your miles per gallon.
- Speedometer Accuracy: Your speedometer will underreport your actual speed by about 6.8%. For instance, when your speedometer reads 20 mph, you’ll actually be traveling at 21.36 mph. This discrepancy can be significant at higher speeds and may require recalibration.
- Ride Comfort: The taller sidewall of the 275/65R20 tire (7.04 inches vs. 5.95 inches) can provide a smoother ride by absorbing more road imperfections. However, this may also lead to a slight decrease in handling responsiveness.
- Acceleration and Braking: The larger tires have more rotational mass, which can slightly reduce acceleration and increase braking distances. This effect is usually minimal but may be noticeable during quick maneuvers.
- Durability & Wear: The larger contact patch of the 275/65R20 tires may distribute weight more evenly, potentially leading to more even wear. However, the softer compound often used in larger tires might wear faster on paved roads.
Off-Road Impact
For off-road enthusiasts, the switch to 275/65R20 tires can bring several advantages. Here’s how these larger tires can enhance your off-road experience:
- Ground Clearance: The 2.17-inch increase in overall diameter translates to about an inch of additional ground clearance. This can be a game-changer when navigating rough terrain, allowing you to clear larger obstacles with ease.
- Traction: The larger contact patch of the 275/65R20 tires can provide better traction in loose or muddy conditions. This can improve your vehicle’s off-road capability and stability.
- Flotation: In soft terrains like sand or snow, the wider footprint of the larger tires helps distribute the vehicle’s weight over a larger area, reducing the risk of getting stuck.
- Rock Crawling: The taller sidewalls offer better protection against rock damage and allow for more aggressive “airing down” to increase traction in extreme off-road conditions.
- Aesthetics: The larger 275/65R20 tires give your vehicle a more aggressive, off-road-ready appearance. This “lifted” look is often desirable among off-road enthusiasts.
275/55r20 vs 275/65r20 Table
The most significant difference between 275/55R20 and 275/65R20 tires is the 6.8% increase in overall diameter.
| Feature | 275/55R20 | 275/65R20 | Difference |
|---|---|---|---|
| Diameter inches (mm) | 31.91 (810.5) | 34.07 (865.5) | 2.17 (55) +6.8% |
| Width inches (mm) | 10.83 (275) | 10.83 (275) | 0 (0) 0% |
| Circumference inches (mm) | 100.25 (2546.26) | 107.05 (2719.05) | 6.8 (172.79) +6.8% |
| Sidewall Height inches (mm) | 5.95 (151.25) | 7.04 (178.75) | 1.08 (27.5) +18.2% |
| Revolutions per mile (km) | 632.04 (392.73) | 591.88 (367.78) | -40.16 (-24.96) -6.4% |
| Speedo Reading | 20 mph | 21.36 mph | +1.36 mph |
Can I Use 275/65r20 Instead of 275/55r20?
No, you should not use 275/65r20 instead of 275/55r20 because the diameter difference exceeds the recommended 3%. This can affect vehicle handling, speedometer accuracy, and fuel efficiency.
It’s best to stick with the original 275/55r20 tire size or find a replacement that is within the 3% diameter difference guideline.
How Much Taller Is a 275/65r20 Tire Than a 275/55r20?
A 275/65r20 tire is 2.17 inches taller than a 275/55r20 tire, with the former having a diameter of 34.07 inches compared to 31.91 inches for the latter.
What is the Difference Between 275/55r20 and 275/65r20?
The main difference between 275/55r20 and 275/65r20 tires is a 6.8% increase in overall diameter, making the 275/65r20 larger and more suitable for off-road performance while impacting fuel efficiency and speedometer accuracy
Our Observation
Switching from 275/55R20 to 275/65R20 tires offers a mix of benefits and drawbacks. Off-road, the larger tires shine with improved ground clearance, traction, and capability.
The aesthetic upgrade is also significant, giving your vehicle a more imposing presence. However, on-road performance may see some compromises.
The slight decrease in fuel efficiency and the need for speedometer recalibration are notable considerations. For daily driving, the impact on acceleration, braking, and handling is generally minimal and may be offset by improved ride comfort.
Ultimately, this tire size switch is best suited for those who prioritize off-road performance and aesthetics over minor on-road trade-offs.
Caitlin McCormack is a lead writer at Tiresizecompare.com and a trusted guide at AmarCalculator. With an extensive background in finance and mathematics, she simplifies complex calculations and delivers precise insights. Caitlin’s expertise ensures readers receive accurate and reliable information to make informed decisions. Her passion for numbers and dedication to clarity make her an invaluable resource for tire comparisons.
