How Big Is a 285 Tire? Dimensions, 33-Inch Specs & Fitment
In the off-road, overlanding, and pickup truck modification community, few tire sizes are as revered or popular as the legendary 285 tire. When truck and SUV owners decide to give their vehicle an aggressive, brawny stance and serious all-terrain traction, the first question they research is: how big is a 285 tire? In metric tire terminology, the number "285" designates the tire section width in millimeters, which translates to exactly 11.22 inches wide from sidewall to sidewall. Depending on the accompanying sidewall aspect ratio and wheel rim diameter, a 285 tire stands between 31.5 inches and 35 inches tall, with sizes like 285/70R17 serving as the gold-standard "true 33-inch tire."
Comprehensive Overview and Foundational Insights
Decoding a metric tire code requires understanding that tire size is a three-dimensional geometric equation. In a tire size like 285/70R17, the "285" is the section width in millimeters (11.2 inches). The "70" is the aspect ratio, meaning the sidewall height is 70% of the 285mm width (7.85 inches of sidewall). The "17" is the wheel rim diameter in inches. Combining both sidewall heights with the 17-inch wheel yields an overall tire diameter of exactly 32.7 inches tall—universally recognized in off-roading as a true 33-inch tire.
Stepping up to a 285-width tire delivers aggressive aesthetic muscularity, increased ground clearance beneath differential pumpkins, and an expanded contact patch for crawling over rocks, deep sand, and mud. However, because 285 tires are wider and taller than factory stock tires, understanding potential fender rubbing, body mount chop requirements, speedometer gearing adjustments, and wheel offset considerations is essential.
Popular 285 Tire Sizes: Dimensions in Inches and Off-Road Heights
| Metric Tire Size Code | Section Width in Inches | Sidewall Height | Overall Tire Diameter (Height) | Equivalent Flotation Size / Vehicle |
|---|---|---|---|---|
| 285/50R20 | 11.2 inches (285 mm) | 5.6 inches (142 mm) | 31.2 inches tall | Sport truck size; Dodge Ram, Toyota Land Cruiser 20" |
| 285/60R18 | 11.2 inches (285 mm) | 6.7 inches (171 mm) | 31.5 inches tall | Toyota Tundra, Lexus LX570, Land Cruiser 200 series |
| 285/65R18 | 11.2 inches (285 mm) | 7.3 inches (185 mm) | 32.6 inches tall (~33") | Chevy Silverado 1500, GMC Sierra, leveled F-150s |
| 285/70R17 | 11.2 inches (285 mm) | 7.9 inches (200 mm) | 32.7 inches tall (True 33") | Jeep Wrangler Rubicon, Gladiator, Toyota Tacoma/4Runner |
| 285/75R16 | 11.2 inches (285 mm) | 8.4 inches (214 mm) | 32.8 inches tall (True 33") | Classic Toyota Tacoma Gen 2, Chevy Silverado 2500HD |
| 285/70R18 | 11.2 inches (285 mm) | 7.9 inches (200 mm) | 33.7 inches tall (~34") | Leveled Ford F-250, Ram 2500, overland Toyota Tundras |
| 285/75R17 | 11.2 inches (285 mm) | 8.4 inches (214 mm) | 33.8 inches tall (~34") | Popular overland "tall-skinny 34" tire for lifted 4x4s |
| 285/75R18 | 11.2 inches (285 mm) | 8.4 inches (214 mm) | 34.8 inches tall (True 35") | True 35" tall tire with narrow 11.2" footprint on heavy trucks |
In-Depth Analysis and Comparative Benchmarks
The nominal section width of any 285 tire is exactly 11.22 inches (285 millimeters). This 11.2-inch width represents the perfect middle ground between narrow factory tires (typically 10.2 to 10.5 inches wide) and ultra-wide 12.5-inch aftermarket flotation tires. A 285 tire provides an aggressive, muscular stance that fills out truck wheel wells without protruding far outside the fenders, avoiding the need for gaudy aftermarket fender flares or throwing rocks down your truck’s side doors.
The 285/70R17 size is universally celebrated as the most popular aftermarket off-road tire size in the world. Measuring 32.7 inches tall by 11.2 inches wide, it is the quintessential "33-inch tire." Standard factory equipment on extreme off-road models like the Jeep Wrangler Rubicon, Ford Bronco Badlands, and Chevy Colorado ZR2, this tire size offers deep tread lugs, thick reinforced sidewalls, and ample rubber cushion over rocky terrain.
285 Tire vs 275 Tire vs 33x12.50 Tire Comparison
| Tire Specification | 275 Metric Tire (e.g., 275/70R17) | 285 Metric Tire (e.g., 285/70R17) | 33x12.50R17 Flotation Tire |
|---|---|---|---|
| Section Width in Inches | 10.83 inches wide | 11.22 inches wide (+0.4" wider) | 12.50 inches wide (+1.3" wider) |
| Overall Height (Diameter) | 32.2 inches tall | 32.7 inches tall (+0.5" taller) | 32.8 to 33.0 inches tall |
| Fender Rubbing Risk | Minimal on stock / leveled trucks | Moderate on midsize trucks (needs 2-3" lift) | Severe rubbing on control arms; needs wide offset wheels |
| Tire Weight (E-Load) | ~50 to 54 lbs per tire | ~54 to 60 lbs per tire | ~62 to 68 lbs per tire |
| Snow & Rain Hydroplaning | Superior road tracking and snow bite | Excellent balanced all-weather traction | High hydroplaning risk; floats over deep water/mud |
Strategic Guidance and Expert Recommendations
Fitment on midsize trucks (such as the Toyota Tacoma, 4Runner, and Chevy Colorado) requires careful modification planning. While full-size half-ton trucks (like the Ford F-150 and Chevy Silverado 1500) can fit 285/70R17 or 285/65R18 tires with just a simple 2-inch front leveling kit, midsize trucks require more effort. On a Toyota Tacoma or 4Runner, mounting 285/70R17 tires generally demands a 2.5-inch to 3-inch suspension lift, aftermarket upper control arms (UCAs) to restore front caster, front fender liner trimming, and often a Body Mount Chop (BMC) to clear the frame bracket at full steering lock.
Tire weight and drivetrain strain are important considerations when stepping up to a 285 tire. Most 285 all-terrain and mud-terrain tires (such as the BFGoodrich KO2/KO3, Falken Wildpeak A/T4W, or Goodyear Wrangler DuraTrac) feature heavy 10-ply Load Range E construction designed for puncture resistance. These heavy tires weigh between 54 and 60 pounds each—roughly 15 to 20 pounds heavier per corner than factory passenger-rated tires. This added rotational unsprung mass typically results in a 1.5 to 2.5 MPG drop in fuel economy and slightly more sluggish highway passing acceleration.
Wheel rim matching for 285 tires requires rim widths between 7.5 inches and 9.5 inches wide, with 8.0 or 8.5 inches being the optimal sweet spot. When selecting aftermarket wheels, pay close attention to wheel offset and backspacing. An offset between 0mm and +12mm pushes the 285 tire outward just enough to clear the inner steering knuckle and upper control arm ball joint without pushing the tire so far out that it rubs the cab mount.
How to Prepare Your Vehicle for 285 Tires in 5 Steps
A step-by-step modification and installation checklist to ensure 285-width tires fit without rubbing or suspension interference.
Verify Available Wheel Well Clearance and Suspension Lift
Ensure your truck has at least a 2-inch leveling kit (full-size) or 2.5 to 3-inch suspension lift (midsize) to accommodate 33-inch tire height.
Select Wheel Rims with Approved Width and Proper Offset
Choose 17x8.5 or 18x9 inch wheels with 0mm to +12mm offset to clear internal upper control arms and steering linkages.
Inspect and Trim Front Mud Flaps and Plastic Fender Liners
Remove front splash guards and use a heat gun or utility knife to mold plastic inner wheel liners forward to eliminate rubbing during turns.
Mount and Road-Force Balance the 285 Tires
Have a professional off-road tire shop mount and road-force balance the tires, inflating Load Range E tires to 38-42 PSI for proper road contact.
Perform an Off-Road Alignment with Increased Positive Caster
Have an alignment technician dial in +3.0 to +4.0 degrees of positive caster using aftermarket UCAs to push the front wheels forward away from the cab mount.
Frequently Asked Questions (8 Questions Answered)
Q1: How many inches is a 285 tire?
A 285 tire is exactly 11.22 inches wide (285 mm / 25.4). Its total height depends on the aspect ratio, typically ranging from 31.5 to 34.8 inches tall.
Q2: Is a 285/70R17 considered a 33-inch tire?
Yes! A 285/70R17 tire measures 32.71 inches in overall diameter and 11.22 inches in width, which is universally recognized as a true 33-inch tire.
Q3: Can I put 285 tires on a stock truck without a lift?
On full-size trucks (like an F-150), 285s can fit stock or with a mild leveling kit. On midsize trucks (like a Tacoma or 4Runner), 285s require a 2.5-3" lift to avoid rubbing.
Q4: How much taller is a 285 tire than a 265 tire?
Comparing 285/70R17 (32.7") to standard stock 265/70R17 (31.6"), the 285 tire is roughly 1.1 inches taller and 0.8 inches wider.
Q5: Will 285 tires hurt my truck’s gas mileage?
Yes. Upgrading to heavy 10-ply Load Range E 285 tires typically decreases fuel economy by 1.5 to 2.5 MPG due to increased rolling resistance and rotational weight.
Q6: What is a Body Mount Chop (BMC) for 285 tires?
A BMC is an off-road modification on Toyota trucks where a protruding corner of the steel frame cab mount is cut and welded with a clearance plate to prevent 285s from rubbing.
Q7: What tire pressure should I run in 285/70R17 E-load tires?
For daily highway driving on midsize and half-ton trucks, maintain 36 to 40 PSI cold; inflate to 50+ PSI only when towing maximum heavy trailer loads.
Q8: Can you mount 285 tires on factory stock wheels?
Yes, provided your factory wheels are at least 7.5 to 8 inches wide. However, high positive factory offsets (+50mm) may cause the tire to rub the upper control arm.
Final Thoughts & Key Takeaways
In conclusion, understanding how big is a 285 tire? dimensions, 33-inch specs & fitment provides essential clarity, practical strategies, and actionable advice. By incorporating these foundational insights, adhering to verified safety guidelines, and following structured best practices, you ensure reliable, long-term outcomes while preventing common mistakes. Stay informed, consult certified professionals when needed, and maintain consistent quality care.