Tire Size 305/70r17 vs 285/70r17

The main difference between 305/70Rr17 and 285/70r17 tires is their section width. 305/70r17 tires are 20mm wider than 285/70r17 tires. This difference in width can significantly impact the performance and handling of your vehicle.

Tire 1 Front View
Tire 2 Front View
Tire 1 Side View
Tire 1 Wheel
circumference 1
Tire 2 Side View
Tire 2 Wheel
/ R
/ R
Parameter235/35 R18205/40 R18Differ.
Tire Height
Section Width
Sidewall Height
Rim Size


Fitment Guide

Replacement tires should generally be within 3% of the original tire’s overall diameter to avoid clearance issues or speedometer inaccuracies.

The overall diameter of 305/70R17 tires is 3.3% larger than 285/70R17 tires. So 285/70R17 tires would be a direct replacement, while 305/70R17 tires might require adaptations like a lift kit to accommodate the larger size.

Ground Clearance

The 305/70R17 tire size provides 0.55 inches (14mm) more ground clearance than the 285/70R17 size due to its taller sidewall profile.

This added clearance is useful for off-road driving, helping prevent scrapes and damage from obstacles. However, the larger 305/70R17 diameter also causes a lower speedometer reading than the 285/70R17.

Gas Mileage

The wider 305/70R17 tires have more rolling resistance and rotational mass compared to 285/70R17 tires.

This generally leads to slightly worse fuel efficiency with the 305 widths. So, the narrower 285/70R17 is a better choice for optimal gas mileage.

Ride Comfort

The taller sidewall and wider tread of 305/70R17 tires provide more cushioning and the ability to absorb impacts from rough roads.

This can contribute to a more comfortable ride, especially over uneven terrain. The lower profile 285/70R17 transmits more road noise and vibration into the cabin.


Subjectively, the taller sidewall of the 305/70R17 gives a more aggressive, robust look compared to the lower profile 285/70R17.

This stretched aesthetic suits trucks and SUVs well. However, the 285 width is more aerodynamic.

Handling & Stability

The shorter sidewall and narrower width of the 285/70R17 tire provide sharper, more responsive handling on paved roads.

The 305/70R17’s taller sidewall flexes more, reducing handling precision slightly. Both offer stable performance, but the 285 width has a handling advantage.

Noise & Vibration

The extra cushioning of the 305/70R17 helps absorb road noise and vibrations, leading to a slightly quieter, smoother ride.

The stiffer 285/70R17 sidewall transmits more noise and vibration into the cabin over bumps. However, both tires perform well in this regard.

Durability & Wear

The wider 305/70R17 tread contacts the road with more surface area, distributing wear more evenly across the tire.

This can potentially increase tread life. However, the added weight of 305-width tires also puts more strain on suspension components.

Adverse Conditions

The 285/70R17 tires’ narrower profile allows them to cut through snow more efficiently.

But, the taller 305/70R17 sidewall provides more flexible traction on loose surfaces like mud or sand. Performance in rain, snow, and off-road is comparable.

Speedometer Difference

The larger diameter 305/70R17 tires will register a lower speedometer reading than the 285/70R17s at a given speed.

For example, at an actual speed of 20 mph, the speedometer reads 19.35 mph with 305/70R17 tires fitted.

Can I use 285/70r17 instead of 305/70r17?

No, it is not advisable to use 285/70r17 instead of 305/70r17. The diameter difference is -1.1 inches (-3.3%), exceeding the recommended 3% limit. This variance may affect vehicle performance and the accuracy of speedometer readings.

305/70r17 vs 285/70r17

285/70r17 vs 305/70r17

This comparison table will help you understand the differences between 285/70r17 and 305/70r17 tire sizes.

How Much Taller Is A 305/70r17 Tire Than A 285/70r17?

The 305/70r17 tire is 1.1 inches (28 mm) taller than the 285/70r17 tire, representing a 3.3% increase in diameter.

The height of a 305/70r17 tire is 33.81 inches (858.8 mm), and a 285/70r17 tire has a height of 32.71 inches (830.60 mm).

How Much Wider Is A 305/70r17 Tire Than A 285/70r17?

The 305/70r17 tire is 0.79 inches (20 mm) wider than the 285/70r17 tire, indicating a 6.6% increase in width.

Specifically, the 305/70R17 measures 12.01 inches (305mm) in width, while the 285/70R17 is narrower at 11.22 inches (285mm).

What Does 305/70r17 Mean?

The tire size 305/70R17 denotes a tire that is 305 millimeters wide, with a 70% aspect ratio (height to width), radial construction (denoted by “R”), and designed for a 17-inch wheel. The equivalent measurement in inches for the tire size 305/70R17 is 33.9x12R17.

What Does 285/70r17 Mean?

The tire size 285/70R17 specifies a tire that is 285 millimeters wide with a 70% aspect ratio. The tire has a radial construction, indicated by the “R,” and is designed to fit on a 17-inch wheel. The tire dimensions 285/70R17 can be expressed as 32.8×11.2R17 in inches.

What Size Rim For 285/70r17?

The tire size 285/70r17 can be mounted on a 17-inch wheel. For a 285/70R17 tire, the recommended rim width ranges from 7.5 to 9.0 inches.

What Size Rim For 305/70r17?

The tire size 305/70R17 can be accommodated on a 17-inch wheel. To ensure the optimal fit, it is recommended to use a rim with a width between 8.0 and 9.5 inches.

Our Observation
Based on the differences analyzed, the 285/70R17 tire size seems better suited for on-road use, providing enhanced handling, efficiency, and a smoother ride on paved surfaces.

Meanwhile, the 305/70R17 size offers excellent off-road capability and a more comfortable ride over rough terrain thanks to its taller sidewall and wider tread.

Ultimately, we recommend the 285/70R17 tire for drivers who spend most of their time on highways and city streets.

For off-road adventurers or those needing maximum ground clearance, the 305/70R17 is a better choice. Select the tire that aligns with your vehicle’s main usage.

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