2018 Kenworth W900 Tire Size, Pressure & Wheel Specs

As an ASE-certified master technician, I know firsthand that maintaining the tires on a Class 8 heavy-duty truck like the 2018 Kenworth W900 is critical for safety, fuel economy, and DOT compliance. Because the W900 is highly customizable for over-the-road (OTR), vocational, or heavy-haul applications, your exact tire specifications will depend on the gross axle weight rating (GAWR) and how the truck was spec'd from the factory.

Below is the comprehensive guide to tire sizes, pressures, and wheel specs for the 2018 Kenworth W900.

Quick answer

• OEM tire size: Typically 11R22.5, 11R24.5, 295/75R22.5, or 285/75R24.5 (Steer and Drive). Heavy haul may feature 385/65R22.5 or 425/65R22.5 on steer/lift axles.
• Recommended cold tire pressure (door placard): Generally 105–110 PSI for Steer axles and 95–100 PSI for Drive axles (varies by load rating).
• Bolt pattern: 10x285.75mm (Hub-piloted).
• Wheel size: 22.5" x 8.25" or 24.5" x 8.25" (wider for flotation tires).
• Load index/Speed rating: Load Range G (14-ply), H (16-ply), J (18-ply), or L (20-ply). Speed rating typically L (75 mph) or M (81 mph).
• Spare tire size: Not standard (depends on fleet spec/headache rack mount).
• TPMS frequency: 433 MHz (if equipped with Bendix SmarTire or similar factory/aftermarket systems).

Tire sizes by Application / Axle

Because the W900 isn't sold in traditional "trims" like a passenger car, tire sizes are dictated by axle placement and hauling application. Always check the driver’s side door jamb VIN plate for your specific truck's GAWR and tire specs.

Recommended replacement tires

When replacing tires on a W900, matching the tread pattern to the axle (steer vs. drive vs. trailer) is mandatory. Here are top recommendations based on commercial applications:

1. Michelin X Line Energy Z / D (Premium): The gold standard for over-the-road fuel efficiency and long tread life. Excellent low rolling resistance for highway hauling.
2. Bridgestone R213 / M713 (Premium): Highly durable steer and drive options with excellent casing integrity, making them ideal for multiple retreads.
3. Goodyear Endurance WHA / LHD (Mid-Tier to Premium): Solid all-around performers for regional and long-haul W900s, offering deep tread depth and excellent wet traction.
4. Yokohama RY617 / TY517 (Mid-Tier): A cost-effective choice for owner-operators looking for a balance of high mileage, reliable traction, and lower upfront cost.

When to inflate to max load psi

As a Class 8 heavy-duty truck, managing tire pressure on the W900 according to your load is a daily task. The max load pressure (often 110 PSI for Load Range G or 120 PSI for Load Range H) molded onto the tire sidewall is the pressure required to carry the tire's absolute maximum weight rating.

You should inflate to the max load PSI (or the specific PSI dictated by a commercial tire load/inflation table) when you are hauling near your maximum Gross Vehicle Weight Rating (GVWR) or the specific GAWR for that axle. Running under-inflated tires with a heavy load causes excessive heat buildup, leading to catastrophic blowouts, casing separation, and reduced retreadability. Conversely, running max PSI while bobtailing or running empty will lead to a harsh ride and accelerated center-tread wear.

Lug nut torque & pattern

Proper wheel installation is a major DOT inspection point and a critical safety factor.

• Bolt Pattern: 10-lug on 285.75mm (Hub-piloted).
• Torque Spec: 450 – 500 ft-lbs.
• Procedure: Always use a calibrated 1-inch drive torque wrench. Snug the nuts in a star pattern, then apply final torque in the same star pattern. Retorque all lug nuts after the first 50 to 100 miles of driving following a wheel removal.

Common tire issues for this vehicle

1. Irregular Steer Tire Wear: W900s have massive front ends. Alignment issues (toe, camber, or caster), worn kingpins, or loose tie rod ends will quickly cause river wear, cupping, or shoulder wear on expensive steer tires.
2. Drive Tire Heel/Toe Wear: Usually caused by mismatched tire diameters in dual assemblies or suspension issues (like worn shock absorbers or torque rods). Always ensure duals are matched within 1/4-inch in diameter.
3. Valve Stem Leaks: Due to the severe conditions these trucks operate in, brass valve stems can loosen or corrode. Always use high-quality metal valve caps with rubber O-rings to seal the core.

Need new tires? Find a trusted shop on Repairius.