Tire Size 275/65r20 vs 305/55r20
The main difference between the 275/65r20 and 305/55r20 tires is the section width. The 275/65r20 tire has a section width of 275 millimeters, while the 305/55r20 tire has a section width of 305 millimeters. This means the 305/55r20 tire is wider than the 275/65r20 tire.
275/65r20 vs 305/55r20
This table will assist you in quickly comprehending the distinctions.
Fitment Guide
The 305/55R20 tire is about 2.5% smaller in overall diameter compared to the 275/65R20. This is within the 3% limit for direct replacement without modifications.
However, the 10.9% increase in width with the 305/55R20 may cause clearance issues depending on the wheel well space. Wider tires may require wheel spacers or other adjustments to prevent rubbing at full steering lock.
Ground Clearance
With a diameter of 33.21 inches, the 275/65R20 provides 0.86 inches more ground clearance than the 305/55R20 at 32.35 inches.
This added clearance benefits off-road driving by preventing scrapes and damage from obstacles. However, the larger 275/65R20 diameter causes a slightly lower speedometer reading.
The 305/55R20 reduced clearance increases the risks of scrapes but gives a higher speedometer reading.
Gas Mileage
The narrower 275/65R20 has a smaller contact patch and lower rotational mass, providing better fuel efficiency crucial for daily driving.
The wider, heavier 305/55R20 has increased rolling resistance and inertia, detrimentally impacting mileage.
Ride Comfort
The 275/65R20 taller 65 aspect ratio sidewall absorbs road impacts better than the 55 aspect 305/55R20. This cushions the ride, especially over uneven surfaces.
However, the 305/55R20 shorter sidewall gives sportier, more responsive handling preferred by some drivers.
Aesthetics
The 305/55R20 wider tread and lower profile visually convey a more aggressive, performance-oriented look.
However, the taller 275/65R20 sidewall has a classier, more sophisticated aesthetic suiting luxury vehicles. Subjectively, personal taste dictates preference.
Handling & Stability
The 275/65R20 taller sidewall flexes more, reducing handling precision slightly. The 305/55R20 shorter, stiffer sidewall gives sharper, sportier handling.
However, both provide responsive, stable handling for normal driving conditions.
Noise & Vibration
With a shorter sidewall, the 305/55R20 transmits more road noise and vibrations into the cabin.
The 275/65R20 dampens vibrations better for a smoother, quieter ride. But differences are minor, and both perform well in this regard.
Durability & Wear
The narrower 275/65R20 exhibits more even wear across the tread and potentially longer service life.
The wider 305/55R20 sees more stress concentration in the center of the tread, increasing uneven wear. However, both feature durable construction.
Adverse Conditions
Performance in rain, snow, and off-road is comparable, with the 275/65R20 having slightly better snow traction.
The 305/55R20 wider tread provides a bit more grip in mud. Ground clearance favors the taller 275/65R20 for light off-roading.
Speedometer Difference
Due to its larger diameter, the 275/65R20 gives a slightly higher speedometer reading than the 305/55R20.
At an actual speed of 20 mph, the speedometer would read around 19.5 mph with the 305/55R20 tires versus 20 mph with the 275/65R20.
Our Observation
Based on the comparisons, the 275/65R20 is likely the better all-around tire for most drivers. It provides better fuel efficiency, ride comfort, snow traction, and tread life – all crucial factors for daily driving.\
Its taller sidewall also gives it a classier look preferred on many vehicles over the 305/55R20’s aggressive styling. The 305/55R20 is a good option for those prioritizing sportier handling and appearance.
However, for a balance of comfort, wear, efficiency, and all-weather traction, we recommend the more well-rounded 275/65R20 tire for most motorists. Its versatility across areas makes it the better overall choice.

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.