Tire Size 285/65r20 vs 33×12.50r20
The primary distinction between 285/65R20 and 33×12.50R20 tires is their diameter. This means that the 285/65R20 tire is 1.57 inches (39.78 mm) larger in diameter than the 33×12.50R20 tire.
| / | R |
| / | R |
| Parameter | 235/35 R18 | 205/40 R18 | Differ. |
|---|---|---|---|
| Tire Height | |||
| Section Width | |||
| Circumference | |||
| Sidewall Height | |||
| Revolutions | |||
| Rim Size |
Fitment Guide
The 285/65r20 has a 4.5% larger diameter than the 33×12.50r20. This exceeds the 3% diameter difference threshold for direct replacement tires.
The 33×12.50r20 would likely require adaptations like a lift kit to fit properly without rubbing or clearance issues.
Ground Clearance
With a diameter of 34.59 inches, the 285/65r20 provides 1.57 inches more ground clearance than the 33×12.50r20 at 33.02 inches.
This added clearance is beneficial for off-roading by preventing scrapes over obstacles. However, the larger 285/65r20 diameter causes a lower speedometer reading.
Gas Mileage
The 285/65r20 is heavier with more rolling resistance, likely resulting in slightly worse fuel efficiency than the lighter 33×12.50r20. Less rotational mass improves mileage.
Ride Comfort
The taller sidewall and larger air volume of the 285/65r20 absorb impacts better, providing a smoother ride over bumps and uneven terrain. The 33×12.50r20 transmits more road harshness into the cabin.
Aesthetics
The 285/65r20’s larger diameter and taller sidewall have a stretched, aggressive off-road look compared to the 33×12.50r20. This suits trucks and SUVs well. The 33×12.50r20 appears slightly more aerodynamic.
Handling & Stability
The shorter sidewall and smaller diameter of the 33×12.50r20 enable quicker steering response and handling precision.
The taller 285/65r20 sidewall flexes more, reducing handling performance slightly. Both deliver responsive, stable handling overall.
Noise & Vibration
The 33×12.50r20’s stiffer sidewall transmits more road noise and vibration into the cabin. The extra cushioning of the 285/65r20’s sidewall dampens noise and vibration better for a quieter ride.
Durability & Wear
The 285/65r20’s larger size likely wears suspension components faster from increased weight and rotational forces. Even treadwear may be slightly better on the smaller 33×12.50r20.
Adverse Conditions
The narrower 285/65r20 could have an advantage in cutting through snow to the pavement.
The wider 33×12.50r20 provides more traction in mud, thanks to a larger contact patch. Both perform well overall in adverse conditions.
Speedometer Difference
At an actual speed of 20 mph, the speedometer reads 20 mph with 285/65r20 tires equipped.
But with 33×12.50r20 tires, the speedometer reads 19.09 mph. This speedometer difference of 0.91 mph is due to the smaller diameter of the 33×12.50r20 tires.
Is A 33 Tire The Same As A 285?
No, a 33-inch tire is not equivalent to a 285 tire. The difference in diameter between a 285/65R20 tire, which measures 34.59 inches, and a 33×12.50R20 tire, which measures 33.02 inches, is 1.57 inches.
This represents a variance of 4.5%, which exceeds the recommended 3% threshold for safe tire substitution.
What Does 33×12.50r20 Tire Mean?
The first number in a 33×12 50r20 tire size refers to the diameter of the tire in inches, which is 33 inches.
The second number is the section Width of the tire, which is 12.50 inches, and the last number is the size of the wheel in inches, which is 20 inches. The tire size 33×12.50r20 closest equivalent would be 325/50R20 in the metric system.
What Does 285/65r20 Tire Mean?
The 285/65r20 tire is a bit different from a 33×12 50r20. The first number, 285, refers to the width of the tire in millimeters.
The second number, 65, is the aspect ratio, which is the height of the sidewall. The last number, 20, is the wheel diameter in inches. Tire Size 285/65R20 is equivalent to 34.6×11.2R20 in inches.
How Wide Are 33×12.50r20 Tire?
The 33×12.50R20 tire has a section width of 12.5 inches. The width of the tire, from the inner sidewall to the outer sidewall, is captured by this measurement.
How Wide Are 285/65r20 Tire?
The width of a 285/65R20 tire is 11.22 inches or 285 millimeters. This measurement signifies the tire’s width from the inner to outer sidewall.
How Much Taller Is A 285/65r20 Tire Than A 33×12.50r20?
The 285/65r20 tire is approximately 1.57 inches (39.78 mm) taller than the 33×12.50r20 tire, representing a 4.5% increase in diameter.
The 285/65r20 tire size boasts a height of 34.59 inches (878.5mm), while the 33×12.50r20 tire size registers around 33.02 inches (838.72mm) in height.
What Size Rim Fits A 33×12.50r20?
The 33×12.50R20 tire is compatible with wheels that have a rim width of 20 inches and a range of 8.5 to 11 inches. For the best performance, it is recommended to keep the tire and wheel widths within 3 inches of each other.
What Size Rim Fits A 285/65r20?
The 285/65R20 tire is suitable for mounting on wheels that have a rim width of 20 inches, with a range between 8.5 and 11 inches.
For best performance, it is advisable to maintain a difference of no more than 3 inches between the widths of the tire and the wheel.
33×12.50r20 vs 285/65r20
Our Observation
While the 33×12.50R20 offers marginally better handling and efficiency, the difference is minor compared to the 285/65R20. The larger tire provides more significant advantages in ground clearance, off-road traction, and ride quality over uneven terrain.
Given the modest on-road handling gain with the 33″ tire, we recommend the 285/65R20 as the best overall choice.
The slight diameter difference has little impact on street driving, whereas the larger size’s extra clearance and cushioning deliver more versatile all-terrain performance. The 285/65R20 strikes the optimal balance for mixed on and off-road use for most drivers.
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.
