Tire Size 275/70r18 vs 275/65r20
Swapping out your stock 275/70R18 for a sleek set of 275/65R20 can give your vehicle a whole new look and feel.
But before you make the switch, it’s important to understand the key differences between these two tire sizes and how they can impact your driving experience. 275/65R20 tires
- Improved on-road handling and responsiveness
- Slightly firmer ride quality compared to 275/70R18
- Minor inaccuracy in speedometer readings (reads slow)
- More aggressive and modern aesthetic appeal
- Marginally less traction in loose off-road conditions
- Negligibly heavier than 275/70R18 tires
275/70r18 vs 275/65r20
This table provides an easy-to-comprehend comparison of the differences.
Fitment Guide
The new set should be within 3% of the original tire’s overall diameter when replacing tires to avoid clearance issues or speedometer inaccuracies.
The 275/65R20 is 2.8% larger in overall diameter than the 275/70R18, so it falls within the acceptable range.
However, the taller 275/70R18 may require minor adaptations like a small lift kit to prevent rubbing at full turn.
Ground Clearance
With a diameter of 34.07 inches, the 275/65R20 provides 1.01 inches more ground clearance than the 33.16 inch 275/70R18.
This added clearance helps prevent scrapes and damage over rough terrain. However, the larger 275/65R20 diameter causes a lower speedometer reading than the 275/70R18.
Gas Mileage
The 275/70R18’s smaller contact patch and lighter weight provide slightly better fuel efficiency over the larger 275/65R20.
Reduced rolling resistance and rotational mass allow it to confer a modest gas mileage benefit, making it ideal for daily driving.
Ride Comfort
The extra 0.54 inches of sidewall cushioning enables the 275/70R18 to absorb bumps and cracks more smoothly.
Its flexible sidewall dampens road impacts versus the shorter 275/65R20 sidewall, leading to a more comfortable ride over uneven surfaces.
Aesthetics
Visually, the difference is subtle. The 275/70R18’s taller 70 aspect ratio gives it a slightly “stretched” look over the 275/65R20.
This taller sidewall aesthetically suits trucks and SUVs better than a lower-profile tire.
Handling & Stability
The 275/65R20’s shorter sidewall provides sharper handling and quicker response on the pavement.
Meanwhile, the 275/70R18’s additional flex absorbs impacts better, delivering good stability off-road. Both offer responsive handling overall.
Noise & Vibration
With a shorter and stiffer sidewall, the 275/65R20 transmits more road noise and vibration into the cabin. The 275/70R18’s extra sidewall flex helps dampen vibrations, leading to a smoother and quieter ride.
Durability & Wear
The 275/65R20’s smaller size can promote more even treadwear and slightly longer-lasting treads. The larger 275/70R18 is more heavily stressed and can cause added wear on suspension components.
Adverse Conditions
Both tires handle rain, snow, and off-road conditions well. The 275/70R18’s extra ground clearance gives a slight advantage off-road, while the 275/65R20 is a bit more responsive in snow due to its shorter sidewall.
Speedometer Difference
At an actual speed of 20 mph, the speedometer reads 20.55 mph with 275/65R20 tires versus 20 mph with 275/70R18 tires.
The larger diameter 275/65R20 causes a higher speedometer reading of 0.55 mph than the smaller 275/70R18 at the same actual speed.
What is the Main Difference Between 275/70r18 and 275/65r20?
The main difference between 275/70R18 and 275/65R20 tires is the sidewall height. The 275/65R20 tires have a shorter sidewall, which can impact ride comfort and off-road capability.
Can I Use 275/65r20 Instead of 275/70r18?
Yes, you can use 275/65R20 tires in place of 275/70R18 since the difference in overall diameter is within the acceptable range of 3%.
However, be aware that this change can slightly impact ride quality, speedometer accuracy, and off-road performance.
How Much Taller is a 275/65r20 Tire Than a 275/70r18?
A 275/65R20 tire is approximately 0.92 inches (23.3 mm) taller than a 275/70R18 tire. This increased height equates to a 2.8% difference in overall diameter between the two sizes.
Our Observation
After weighing the differences between 275/70R18 and 275/65R20 tires, it’s clear that making the switch comes with both benefits and compromises.
The shorter sidewall of 275/65R20 provides sharper on-road handling at the expense of ride comfort and off-road compliance.
They’ll also raise your vehicle slightly and may make your speedometer read a hair slow. Ultimately, whether the tradeoffs are worthwhile comes down to your specific vehicle, driving style, and intended use.
If you prioritize on-road performance and like the look of a shorter tire, 275/65R20 are a compelling choice.
But if you frequently venture off-pavement or just want a softer, more compliant ride, you may be better off sticking with tried-and-true 275/70R18. There’s no universally right answer – it all depends on your needs and preferences as a driver.
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.