Tire Size 255/70r17 vs 285/70r17
The main difference between the two tire sizes is that the 285/70r17 is wider than the 255/70r17. The 285/70r17 tire size is around 30 millimeters wider than the 255/70r17 tire size.
This means that the 285/70r17 tire will provide a wider contact patch with the road, which can improve handling and cornering performance.
| / | R |
| / | R |
| Parameter | 235/35 R18 | 205/40 R18 | Differ. |
|---|---|---|---|
| Tire Height | |||
| Section Width | |||
| Circumference | |||
| Sidewall Height | |||
| Revolutions | |||
| Rim Size |
Fitment Guide
When replacing tires, the new tires should be within 3% of the original tire’s overall diameter to avoid clearance issues or speedometer errors.
The 285/70r17 is 5.3% larger in overall diameter than the 255/70r17, so it may require modifications like a suspension lift to fit appropriately and prevent rubbing at complete turn.
Larger tires, like the 285/70r17, may need more room to fit without scraping or rubbing.
Ground Clearance
The 285/70r17 provides 1.65 inches (42mm) more ground clearance than the 255/70r17, which is beneficial for off-road driving over rough terrain.
However, the larger diameter causes a lower speedometer reading. The 255/70r17 has less clearance, increasing risks of scraping, but gives a higher speedometer reading.
Gas Mileage
The 285/70r17 larger size and heavier weight results in slightly worse gas mileage than the 255/70r17.
The 255/70r17 smaller contact patch and lower rotational mass improve fuel efficiency, which is ideal for daily driving.’s
Ride Comfort
The 255/70r17 offers a slightly firmer, sportier ride, while the 285/70r17 provides more cushioning and impact absorption from its taller sidewall.
This makes the 285/70r17 more comfortable over very uneven roads or rugged terrain.
Aesthetics
Visually, the 285/70r17 has a modestly taller sidewall than the 255/70r17, giving it a slightly more aggressive, off-road look.
The 255/70r17 has a lower profile appearance that some prefer for a sportier look.
Handling & Stability
The 255/70r17 provides crisper handling and steering response on pavement due to its shorter, stiffer sidewall.
The 285/70r17 flexible sidewall reduces handling precision slightly but offers better stability off-road.
Noise & Vibration
Due to its stiff sidewall, the 255/70r17 transmits more road noise and vibration. The 285/70r17 dampens noise and vibration better through its additional air volume and sidewall flex. However, both are relatively quiet and smooth.
Durability & Wear
The 255/70r17 exhibits slightly more even treadwear and a marginally longer lifespan. The heavier 285/70r17 causes more wear on vehicle components, but its larger size can better withstand impacts.
Adverse Conditions
The narrower 255/70r17 in snow may cut through to the pavement more effectively.
The wider 285/70r17 provides better traction in muddy or loose dirt conditions. Both perform well in rain, snow, and off-road.
Speedometer Difference
Due to its larger overall diameter, the 285/70r17 causes the speedometer to read slightly higher than the actual speed compared to the 255/70r17.
At 20 mph actual speed, the 285/70r17 reads 21.06 mph while the 255/70r17 reads 20 mph.
How Much Bigger Is A 285 Tire Than A 255?
The 285/70R17 tire is approximately 1.65 inches (42 mm) bigger in diameter than the 255/70R17 tire . This difference in tire diameter also results in a 5.0% to 5.1% variance in the speedometer reading.
255/70r17 vs 285/70r17
Here’s a comparison table that will help you easily understand the differences between the options.
Our Observation
Regarding comparing 255/70r17 vs 285/70r17 tires, the 285/70r17 is better suited for off-roading and rugged terrain with its added ground clearance, cushioned ride, and improved traction.
However, the 255/70r17 is ideal for street driving thanks to its responsive handling, even treadwear, and fuel efficiency.
Though differences are modest between 255/70r17 vs 285/70r17, we’d recommend the 285/70r17 for truck or SUV owners who frequently go off-road.
For commuter vehicles and street driving, the 255/70r17 is likely the better choice for its blend of ride comfort, longevity, and efficiency. Select tires based on your intended driving 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.
