The 285/70R18 tire measures 33.8 inches (859 mm) in overall diameter, 11.2 inches (285 mm) in tread width, and fits an 18-inch (457 mm) wheel. Its sidewall height is 7.9 inches (201 mm), with a circumference of about 106.1 inches (2695 mm), giving roughly 597 revolutions per mile (371 per kilometer).
This size strikes an excellent balance of durability, traction, and ride comfort, making it a go-to option for trucks and SUVs. Whether you’re cruising highways, towing heavy loads, or tackling off-road trails, 285/70R18 tires provide the stability and grip you need.
You can explore more about tire sizes on our blog for better understanding and selection.
Understanding Tire Dimensions: 285/70R18 in Inches and Mm
Now that we know what 285/70R18 means, let’s break it down further into exact measurements in both inches and millimeters. This will help you understand how this tire size affects your vehicle’s performance.
| Measurement | Inches | Millimeters |
| Tire Width | 11.2 in | 285 mm |
| Circumference | 105.8 in | 2,691 mm |
| Wheel Diameter | 18 in | 457.2 mm |
| Overall Diameter | 33.8 in | 857 mm |
| Sidewall Height | 7.9 in | 200 mm |
| Revolutions per Mile | 599 | — |
These measurements play a crucial role in your driving experience, affecting everything from ride comfort to fuel efficiency and off-road capability. Let’s explore why the overall diameter and sidewall height are so important.
Breaking Down the 285/70R18 Tire Size
Every number in 285/70R18 represents an important measurement that affects how your tire performs. Let’s decode what each part means:
- 285 – This is the tire’s width in millimeters. Converting it to inches, it’s 11.2 inches wide, providing a strong grip on the road and better stability.
- 70 – This refers to the aspect ratio, which means the sidewall height is 70% of the tire’s width. In this case, it’s 7.9 inches, offering a balance between comfort and responsiveness.
- R – The “R” stands for radial construction, the most common design in modern tires. Radial tires last longer and provide better fuel efficiency compared to older bias-ply tires.
- 18 – This number tells us the diameter of the wheel (rim) the tire is designed for—in this case, 18 inches.
Why do these numbers matter? Because they determine how the tire fits your vehicle, its ability to handle different terrains, and even your fuel consumption. A wider tire like 285/70R18 gives you more road contact for better traction, while a taller sidewall absorbs road shocks, making it ideal for both city roads and rugged trails.
Converting 285/70R18 in Inches: A Step-by-Step Guide
Tire sizes are usually measured in millimeters, but understanding them in inches makes it easier to compare options and ensure the right fit. Here’s how 285/70R18 converts to inches:
- Tire Width: The first number, 285 mm, is the tire’s width. Since 1 inch = 25.4 mm, we calculate:
285 ÷ 25.4 = 11.2 inches - Sidewall Height: The second number, 70, is the aspect ratio (percentage of width). We multiply:
11.2 inches × 0.70 = 7.9 inches - Wheel Diameter: The final number, 18, is already in inches—this is the required rim size.
- Overall Diameter: To find the full height of the tire, we add the top and bottom sidewalls to the wheel diameter:
(7.9 × 2) + 18 = 33.8 inches
How Tire Height Affects Ride Comfort and Handling?
The sidewall height of 7.9 inches plays a major role in how your vehicle absorbs shocks, handles bumps, and responds to steering inputs.
Why Sidewall Height Matters?
A taller sidewall like the one on 285/70R18 tires provides:
- Better shock absorption, reducing road vibrations for a smoother ride.
- More flex in off-road conditions, which helps maintain traction on uneven surfaces.
- Extra protection against potholes and road debris, reducing the risk of wheel damage.
Shorter vs. Taller Sidewalls: On-Road vs. Off-Road Performance
- Shorter Sidewalls (Low Profile Tires)
- Better cornering stability but harsher ride.
- More suited for highway and performance driving.
- Less protection against road imperfections.
- Taller Sidewalls (Like 285/70R18)
- Absorb shocks better, making them great for off-road trails and rough roads.
- Provide a more comfortable and cushioned ride.
- More sidewall flex allows for better grip on loose surfaces like sand or mud.
Are 285/70R18 All-Terrain Tires Right for You?
If you’re looking for a tire that performs well both on highways and rugged terrains, all-terrain (A/T) tires in 285/70R18 size could be your best bet. These tires are built to handle a mix of pavement and off-road surfaces, giving you the flexibility to drive in different conditions without swapping tires.
Key Features of All-Terrain Tires
All-terrain tires in 285/70R18 are designed to provide:
- Balanced traction on both paved roads and off-road trails.
- Durable tread patterns that resist wear and improve longevity.
- Stronger sidewalls to prevent punctures from rocks and debris.
- Decent road comfort while still offering off-road grip.
All-Terrain vs. Mud-Terrain vs. Highway Tires
Choosing between all-terrain, mud-terrain, and highway tires depends on where you drive most often. Here’s a quick comparison:
| Tire Type | Best For | Pros | Cons |
| All-Terrain (A/T) | Mixed highway & off-road use | Versatile, durable, good traction | Slightly noisier than highway tires |
| Mud-Terrain (M/T) | Deep mud, rock crawling, extreme off-road | Superior off-road grip, aggressive design | Noisy, reduced highway comfort, shorter lifespan |
| Highway Tires (H/T) | Daily city/highway driving | Quiet, smooth ride, better fuel efficiency | Weak off-road traction, more prone to punctures |
If you need a tire that handles well on highways but can also take you off the beaten path, then 285/70R18 all-terrain tires are a great choice.
Top All-Terrain Tire Brands for 285/70R18
When picking the best all-terrain tires, look for durability, traction, and road comfort. Some of the top-rated brands include:
- BFGoodrich All-Terrain T/A KO2 – Excellent tread life, strong sidewalls.
- Toyo Open Country A/T III – Great wet/dry traction, low road noise.
- Goodyear Wrangler All-Terrain Adventure – Reinforced for off-road strength.
- Falken Wildpeak A/T3W – Good balance of highway comfort and off-road grip.
- Nitto Ridge Grappler – Hybrid between all-terrain and mud-terrain.
If you frequently drive on mixed terrain, all-terrain tires in 285/70R18 offer the best of both worlds—durability, comfort, and off-road capability.
285/70R18 vs. Other Popular Tire Sizes: Which One Fits Best?
Before buying new tires, it’s important to compare 285/70R18 with other similar sizes to see how they differ in terms of traction, stability, fuel economy, and performance.
285/70R18 vs. 275/65R18
- Width Difference: 285 mm vs. 275 mm – The wider 285 tire provides more road grip.
- Sidewall Height: 7.9 inches vs. 7 inches – Taller sidewalls absorb shocks better.
- Overall Diameter: 33.8 inches vs. 32.1 inches – Larger tires improve off-road capability but may reduce fuel efficiency slightly.
👉 Best for: 285/70R18 is better for off-road use, while 275/65R18 may be more fuel-efficient for highway driving.
285/70R18 vs. 275/70R18
- Width Difference: 285 mm vs. 275 mm – Wider tires like 285/70R18 provide better stability.
- Overall Diameter: 285/70R18 is slightly taller, meaning a higher ride height and better off-road traction.
👉 Best for: 285/70R18 is better for rough terrains, while 275/70R18 offers a balance between fuel economy and off-road capability.
Comparison Table for Quick Reference
| Tire Size | Width (in) | Sidewall (in) | Diameter (in) | Best For |
| 285/70R18 | 11.2 | 7.9 | 33.8 | Off-road & highway balance |
| 275/65R18 | 10.8 | 7 | 32.1 | Highway efficiency |
| 265/75R16 | 10.4 | 7.8 | 31.6 | Compact vehicles & fuel savings |
| 285/75R18 | 11.2 | 8.4 | 34.8 | Extreme off-road |
| 275/70R18 | 10.8 | 7.6 | 33.2 | Mixed terrain use |
Best Vehicles for 285/70R18 Tires
Choosing the right tire size for your vehicle is crucial for performance, safety, and longevity. The 285/70R18 tire is a versatile option, commonly found on trucks, SUVs, and off-road vehicles due to its excellent traction, stability, and durability.
Which Vehicles Can Use 285/70R18 Tires?
These tires are designed for larger, high-clearance vehicles that require strong grip and support. Some of the most common vehicles that use 285/70R18 tires include:
- Full-Size SUVs – Ford Expedition, Chevrolet Tahoe, Toyota Land Cruiser
- Heavy-Duty Trucks – Ford F-250, Chevrolet Silverado 2500, Ram 2500
- Off-Road Vehicles – Jeep Wrangler Rubicon, Toyota Tacoma TRD, Ford Bronco
- Work & Utility Trucks – Ford F-150, Toyota Tundra, GMC Sierra
Why 285/70R18 Is Ideal for Towing and Heavy Loads?
If you often tow trailers, boats, or heavy cargo, 285/70R18 tires can make a noticeable difference. Their wide tread and high load-bearing capacity help with:
- Improved stability when carrying heavy loads.
- Better weight distribution, reducing strain on the suspension.
- Enhanced traction to prevent slipping while towing.
Many work trucks and off-road adventurers prefer these tires because they can handle tough conditions without compromising safety.
Final Thoughts
Tires play a huge role in how our vehicles perform, and choosing the right size makes all the difference. After looking into 285/70R18 tires, I’ve realized they offer great stability, traction, and durability, whether you’re driving on highways or tackling rough terrains. Their wider tread and taller sidewalls improve ride comfort and off-road grip, but they do come with slightly lower fuel efficiency and potential speedometer adjustments.
If you frequently drive on mixed terrains, these tires are a solid investment. Regular maintenance, like proper inflation and rotations, will keep them in top shape for years. I always say, taking care of your tires now means fewer problems down the road. Choose wisely, and enjoy the ride!
For tire repair and other maintenance services, visit our tire repair page.
FAQs
Q. How many miles do 285/70R18 tires last?
With proper maintenance, these tires typically last between 50,000 to 80,000 miles, depending on driving conditions and tire quality.
Q. Will 285/70R18 tires affect my fuel efficiency?
Yes, they can slightly reduce fuel efficiency due to their larger size and increased rolling resistance, but proper inflation helps minimize the impact.
Q. Do I need to recalibrate my speedometer after switching to 285/70R18?
If your vehicle originally had smaller tires, a recalibration may be needed since larger tires can cause the speedometer to read lower than actual speed.
Q. Are 285/70R18 tires good for snow and rain?
Yes, all-terrain versions of this size offer good traction on wet and snowy roads, especially if they have deep tread patterns and siping for water dispersion.
Q. What vehicles are compatible with 285/70R18 tires?
These tires are commonly used on trucks, SUVs, and off-road vehicles, including models like the Ford F-150, Jeep Wrangler, Toyota Tacoma, and Chevrolet Silverado.
