2023 Peterbilt 579: Tire Size, Pressure & Wheel Specs

Quick Answer

• OEM Tire Size: 295/75R22.5 (Steer and Drive Axles), 11R22.5 (Steer and Drive Axles)
• Recommended Cold Tire Pressure: Typically 100-110 psi for steer and drive axles (refer to door placard for exact figures)
• Bolt Pattern: 10-hole, 285.75mm bolt circle (hub-piloted)
• Wheel Size: 22.5 x 8.25 inches (standard)
• Load Index/Speed Rating: Varies significantly based on specific tire and axle configuration. Commonly 144/141L or 146/143L for steer and drive tires.
• Spare Tire Size: Generally, a full-size matching tire is recommended, but a spare may not always be carried due to weight/space.
• TPMS Frequency: 433 MHz (common for heavy-duty trucks)

Tire Sizes by Trim

The Peterbilt 579, being a heavy-duty truck, doesn't have "trims" in the same way a passenger car does. Instead, tire sizes are highly dependent on the specific application, axle configuration, and customer specification. Common factory options include:

Axle Type	Common Tire Sizes (Radial)
Steer Axle	295/75R22.5, 11R22.5, 385/65R22.5 (wide base)
Drive Axle	295/75R22.5, 11R22.5, 445/50R22.5 (wide base dual replacement)

It's crucial to verify your specific vehicle's tire and wheel specifications directly from the door jamb placard or the vehicle's build sheet.

Recommended Replacement Tires

When replacing tires on a 2023 Peterbilt 579, commercial-grade tires designed for heavy-duty applications are essential. Here are some popular options across different price tiers:

• Premium Quality (Higher Price Tier):

  • Michelin X Line Energy Z (Steer): Known for fuel efficiency and long tread life. Price: $$$$
  • Goodyear Fuel Max S Endurance (Steer): Excellent for fuel economy and even wear. Price: $$$$
  • Bridgestone M713 Ecopia (Drive): Designed for excellent traction and fuel economy. Price: $$$$

• Mid-Range Quality (Moderate Price Tier):

  • Continental Conti Hybrid HS3 (Steer): A good balance of fuel efficiency and mileage. Price: $$$
  • Hankook AH37 (Steer/All Position): Reliable performance and good durability for regional and long haul. Price: $$$
  • Yokohama 104ZR (Drive): Solid traction and wear in a variety of conditions. Price: $$$

• Value-Oriented (Lower Price Tier):

  • Sumitomo ST719 (Steer): A cost-effective option offering decent mileage and handling. Price: $$
  • Kelly KDA (Drive): Goodyear's value brand, providing dependable performance for various applications. Price: $$

Always ensure replacement tires meet or exceed the OEM load index and speed rating requirements for your specific vehicle configuration.

When to Inflate to Max Load PSI

For heavy-duty trucks like the Peterbilt 579, the recommended cold tire pressure listed on the door placard is typically for the maximum gross vehicle weight rating (GVWR) or gross axle weight rating (GAWR). This means that to safely carry the heaviest loads the truck is designed for, the tires should be inflated to the specified placard pressure.

Running tires underinflated, especially on a heavy truck, can lead to several serious issues:

• Increased Tire Flex and Heat: This can cause premature wear, tread separation, and even blowouts.
• Reduced Fuel Economy: Underinflated tires have higher rolling resistance.
• Poor Handling and Stability: Affects vehicle control, especially when loaded.
• Irregular Wear: Leading to a shorter tire lifespan.

While running empty or with very light loads, some operators might slightly reduce tire pressure for a softer ride, however, this should be done with extreme caution and always in accordance with tire manufacturer guidelines and never below the minimum pressure recommended for the tire's construction type.

Always prioritize safety and adhere to the pressures on your vehicle's door placard or tire manufacturer's load/inflation tables for specific axle weights.

Lug Nut Torque & Pattern

Getting the lug nut torque right is critical for wheel security on a Peterbilt 579. Heavy-duty truck wheels typically use a 10-hole, hub-piloted wheel system.

• Lug Nut Torque: Generally, for 22.5-inch wheels on heavy-duty trucks, the torque specification is around 450-500 ft-lbs (610-678 Nm). Always consult your Peterbilt 579's owner's manual or a certified service manual for the exact torque specifications, as they can vary slightly.

• Tightening Pattern: A star or crisscross pattern should be used to ensure even clamping force across the wheel and hub. Follow these steps:

  1. Hand-tighten all lug nuts.
  2. Tighten in a star pattern to approximately half the final torque value.
  3. Repeat the star pattern to the full torque value.
  4. It's highly recommended to re-check the torque after the first 50-100 miles of operation, and periodically thereafter, especially after any wheel removal or installation.

Common Tire Issues for This Vehicle

Heavy-duty trucks like the Peterbilt 579 are subject to unique tire challenges due to their weight, operating conditions, and mileage accumulation.

• Irregular Wear: Due to alignment issues, improper inflation, or suspension component wear, especially common on steer axles (e.g., feathering, cupping).
• Shoulder Wear: Often caused by underinflation or aggressive cornering, particularly on drive wheels.
• Center Wear: Typically a sign of overinflation, common if tires are inflated to max PSI when consistently running light.
• Heat-Related Damage: Can manifest as tread separation, blistering, or blowouts, often a result of underinflation, overloading, or excessive speed.
• Puncture and Road Hazard Damage: Long-haul trucks are frequently exposed to debris, leading to punctures and impact damage.
• Dual Mismatched Pressures: On dual-tire setups, if tires on the same wheel end have significantly different pressures, the larger tire will carry more load, leading to premature wear on both.

Regular tire inspections, maintaining correct inflation pressures, proper vehicle alignment, and promptly addressing any steering or suspension issues are crucial for maximizing tire life and ensuring safety.

Need new tires? Find a trusted shop on Repairius.