2017 Peterbilt 579 Tire Size, Pressure & Specs

Quick answer

• OEM Tire Size: 295/75R22.5 (Common)
• Recommended Cold Tire Pressure (Placard): 110 psi (Front), 85 psi (Rear)
• Bolt Pattern: 10x285.75mm
• Wheel Size: 22.5" x 8.25"
• Load Index/Speed Rating: 144/141L
• Spare Tire Size: Full-size spare recommended
• TPMS Frequency: Not applicable (typically no factory TPMS)

Tire sizes by trim

Recommended replacement tires

• Michelin X-Line Energy Z (Steer): A premium, fuel-efficient steer tire with excellent mileage potential. ($$$$)
• Bridgestone R283A Ecopia (Steer/All-Position): Known for long life and fuel efficiency, a very popular choice for on-highway applications. ($$$)
• Goodyear Endurance LHD (Drive): A durable and long-lasting drive tire designed for long-haul applications. ($$$)
• BFGoodrich DR444 (Drive): A solid mid-tier drive tire that offers a good balance of performance and value. ($$)
• General Grabber OA (All-Position): A versatile and budget-friendly option suitable for a variety of applications. ($)

When to inflate to max load psi

For a heavy-duty truck like the Peterbilt 579, running the correct tire pressure is critical for safety, fuel economy, and tire life. The recommended cold inflation pressure on the door placard (typically around 110 psi for steer axles and 85 psi for drive axles) is based on the truck's expected gross axle weight rating (GAWR).

You should inflate tires to the maximum pressure indicated on the tire's sidewall only when the axle is loaded to its absolute maximum capacity. Over-inflating tires for a light load can lead to a harsh ride, reduced traction, and accelerated center tread wear. Always weigh the truck to determine the actual axle loads and consult the tire manufacturer's load and inflation tables to find the precise pressure needed for that weight. This ensures the tire maintains its proper shape, supports the load correctly, and maximizes its contact patch with the road.

Lug nut torque & pattern

• Torque Spec: 450–500 ft-lbs
• Pattern: For a 10-lug hub, tighten the nuts in a star or crisscross pattern to ensure the wheel is seated evenly against the hub. Start by snugging all nuts, then tighten in sequence to half the recommended torque, and finally, bring them to the full 450-500 ft-lbs in the same sequence. It is best practice to re-torque the lug nuts after the first 50-100 miles of driving to ensure they are properly seated.

Common tire issues for this vehicle

• River Wear/Cupping on Steer Tires: The 2017 Peterbilt 579, like many modern semi-trucks, is susceptible to irregular wear patterns on steer tires, often called "river wear" or "cupping." This can be caused by a combination of factors including improper alignment (especially toe), worn suspension components (like kingpins and bushings), or imbalanced tires. Regular alignments and tire balancing are critical.
• Mismatched Duals: On the drive axles, ensuring that the dual tires are the same diameter is crucial. A difference of more than 1/4 inch in diameter can cause one tire to carry more load and scrub along the pavement, leading to rapid and irregular wear. Always replace both tires in a dual position at the same time.
• Shoulder Wear on Drive Tires: Due to the high torque from the engine, drive tires can experience shoulder wear, especially if the truck frequently operates on winding roads or in city environments. Maintaining correct inflation pressures and ensuring the axles are properly aligned can help mitigate this issue.

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