Tire Size 275/70r18 vs 275/65r20
The main difference between the 275/70r18 and 275/65r20 tires is in the sidewall height. The tire size 275/70r18 is around 0.54 inch taller than the 275/65r20 tire size. This impacts various performance factors between the two tire sizes.
| / | R |
| / | R |
| Parameter | 235/35 R18 | 205/40 R18 | Differ. |
|---|---|---|---|
| Tire Height | |||
| Section Width | |||
| Circumference | |||
| Sidewall Height | |||
| Revolutions | |||
| Rim Size |
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.
Can I use 225/45R17 instead of 215/45r17?
The 215/45r17 tire has an overall diameter of 24.62 inches (625.3 mm), and the 225/45R17 tire has a diameter of 24.97 inches (634.3 mm).
The difference in diameter between these two tire sizes is around 0.35 inches (or 9 mm), equating to a 1.4% difference.
Since this is less than the recommended maximum difference of 3%, using a 225/45R17 tire instead of a 215/45r17 is possible.
Can I put a 225/45R17 on a 215/45r17?
Whether you can mount a 225/45R17 tire on a 215/45r17 depends on the rim width range. The recommended rim width range for the 215/45r17 tire is 7.0-8.0 inches, while for the 225/45R17 tire, the range is slightly wider, between 7.0-8.5 inches.
Given these specifications, it should be possible to mount a 225/45R17 tire on a rim designed for a 215/45r17, as long as the rim width is within the specified range.
275/65r20 vs 275/70r18
This table provides an easy-to-comprehend comparison of the differences.
Our Observation
Regarding comparing the 275/65R20 and 275/70R18 tire sizes, both deliver solid performance with minor differences.
The 275/65R20 provides slightly increased ground clearance and sharper handling, while the 275/70R18 offers a more comfortable ride quality and improved fuel efficiency.
For most drivers, the 275/70R18’s smoother ride and efficiency make it the best choice overall. The small sacrifice in handling precision outweighs the 275/70R18’s gas mileage and absorbing ride.
We recommend the 275/70R18 for its blend of comfort, visual appeal, and efficiency across various conditions.
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.
