2014 Peterbilt 579 — Tire Size & Pressure

Quick answer

• OEM tire size: Typically 11R22.5 or 275/80R22.5 (steer and drive axles)
• Recommended cold tire pressure (door placard): Varies greatly by load and tire type. Refer to your specific vehicle's door placard. Common ranges are 100-110 psi for steer tires and 85-100 psi for drive tires.
• Bolt pattern: 10-hole, 285.75mm bolt circle diameter (Budd style)
• Wheel size: 22.5 x 8.25 inches (standard for most applications)
• Load index/Speed rating: Varies by tire size and application. Common load range H or J (single configuration) or G (dual configuration) for truck tires, with speed ratings typically L (75 mph) or M (81 mph).
• Spare tire size: Not typically equipped with a spare; commercial trucks often carry a mounted spare or rely on roadside assistance.
• TPMS frequency: 315 MHz or 433 MHz, depending on the specific TPMS system installed. Consult your dealer or service manual.

Tire sizes by trim

The Peterbilt 579 is a highly customizable truck, and tire sizes can vary significantly based on configuration (e.g., axle count, intended use, weight capacity). There aren't "trims" in the traditional passenger vehicle sense. However, common OEM tire sizes include:

Drivers may also opt for wider "super single" tires on drive axles for certain applications, though this is less common on the steer axle. Popular super single sizes include 445/50R22.5.

Recommended replacement tires

Choosing replacement tires for a Peterbilt 579 depends heavily on the intended application (over-the-road, regional, vocational), desired fuel efficiency, and traction requirements. Here are some popular options across different price tiers:

• Premium (High Mileage, Fuel Efficiency):

  • Michelin X Line Energy Z (Steer) / D (Drive): Known for excellent fuel economy and long tread life. Expect a higher upfront cost, but potentially lower operating costs over time. (Price: $$$$)
  • Goodyear Fuel Max S (Steer) / D (Drive): Another strong contender for fuel efficiency and durability, often used in long-haul applications. (Price: $$$$)

• Mid-Range (Good Value, Balanced Performance):

  • Bridgestone R283A Ecopia (Steer) / M710 Ecopia (Drive): Provides a good balance of fuel efficiency, traction, and competitive pricing. (Price: $$$)
  • Continental Hybrid HS3 (Steer) / HD3 (Drive): Designed for regional and long-haul use, offering good wear characteristics and reliable performance. (Price: $$$)

• Value (Cost-Effective, Reliable):

  • Firestone FS591 (Steer) / FD690 (Drive): A popular choice for a more budget-conscious option, offering dependable performance for various applications. (Price: $$)

When to inflate to max load psi

For heavy-duty trucks like the Peterbilt 579, "max load psi" (maximum cold inflation pressure often stamped on the tire sidewall) is not necessarily the recommended operating pressure. Instead, the door placard in your specific truck provides the critical information for proper tire inflation based on the original equipment manufacturer's recommendations for various load scenarios.

However, there are situations where you might approach the maximum stamped pressure on the tire sidewall:

• Operating at or near Maximum Gross Vehicle Weight (GVW) or Gross Axle Weight Rating (GAWR): If your truck is consistently operating with heavy loads that push the limits of its weight capacity, you will need to inflate your tires to higher pressures to safely carry the load. This pressure should still align with your door placard