2017 Peterbilt 389 — Tire Size & Pressure Guide

Quick answer

• OEM tire size: Typically 11R22.5 or 295/75R22.5
• Recommended cold tire pressure (door placard): Varies significantly based on load and axle configuration, often ranging from 85-110 PSI. Always refer to the specific vehicle's tire placard.
• Bolt pattern: 10-hole, 285.75mm bolt circle (10x285.75)
• Wheel size: 22.5" x 8.25" or 24.5" x 8.25"
• Load index/speed rating: Varies by specific tire, but generally J (62 mph) for steer and drive axles, and L (75 mph) or K (68 mph) for trailer applications. Load indexes are very high, often 146/143 (single/dual) or greater.
• Spare tire size: Matches OEM tire size.
• TPMS frequency: Not standard on all heavy trucks from this era for individual tire pressure monitoring. If equipped with an aftermarket system, frequencies vary.

Tire sizes by trim

The Peterbilt 389, being a heavy-duty truck, doesn't have "trims" in the passenger car sense. Tire sizes are primarily dictated by the truck's application, axle configuration, and desired ride/handling characteristics. The most common sizes for the 2017 Peterbilt 389 are:

Larger flotation tires may be used for specific vocational applications, but the above represent the vast majority of on-highway 389s.

Recommended replacement tires

When replacing tires on a Peterbilt 389, it's crucial to select tires designed for commercial, heavy-duty use. These are not passenger car tires and carry significantly higher load ratings and durable construction. Popular and well-regarded options include:

• Michelin X Line Energy (or similar series): Premium tier. Known for excellent fuel efficiency and long tread life. Michelin offers a variety of tires optimized for steer, drive, and trailer positions.
• Goodyear G399 or Marathon Series: Premium tier. Goodyear also provides a comprehensive line of commercial tires with good all-around performance and durability.
• Bridgestone M775 or R283A: Premium tier. Bridgestone is another top contender in the commercial tire market, offering reliable performance and robust construction.
• Continental Hybrid HS3 (steer) / HD3 (drive): Mid-premium tier. Continental offers strong performance and good value in the heavy truck segment.
• Firestone FD691 (drive) / FS591 (steer): Mid-tier. Firestone, a Bridgestone brand, offers dependable and cost-effective solutions for fleet operators and owner-operators.

Prices for heavy-duty truck tires vary widely based on size, brand, and dealer. Expect to pay anywhere from $350 to $700+ per tire.

When to inflate to max load psi

For a heavy-duty truck like the Peterbilt 389, "max load PSI" is a critical consideration. Unlike passenger vehicles where the door placard often provides a single recommended pressure, commercial truck tire pressure is highly dynamic and depends on the actual axle loads. While the tire sidewall lists the maximum permissible cold inflation pressure for a given load, you generally should not inflate to this pressure unless the axle is consistently carrying its maximum rated load.

Always refer to your vehicle's tire placard and consult load/inflation tables from the tire manufacturer. The recommended practice for heavy trucks is to weigh the truck (steer, drive, and trailer axles separately) and then inflate the tires according to the tire manufacturer's load and inflation tables. This ensures proper tire contact, even wear, optimal fuel economy, and safe handling.

Under-inflation can lead to heat buildup, reduced fuel economy, and premature tire failure. Over-inflation can lead to a harsh ride, irregular wear, and reduced traction.

Lug nut torque & pattern

The 2017 Peterbilt 389 uses a 10-hole, 285.75mm bolt circle pattern for its wheels. The lug nuts are typically flange nuts or two-piece nuts, and proper torquing is essential for safety.

• Lug nut torque: Typically between 450-500 ft-lbs (610-678 Nm). Always re-verify this specification with your vehicle's service manual or a reputable Peterbilt service center. This is a high torque value requiring specialized equipment (e.g., a torque multiplier).
• Torque pattern: A star pattern or crisscross pattern should be used when torquing lug nuts to ensure even seating of the wheel. After initial torquing, it is critical to re-torque the lug nuts after the first 50-100 miles of operation and periodically thereafter, especially after any wheel removal or tire service.

Common tire issues for this vehicle

Given the heavy-duty nature and high mileage many Peterbilt 389s accumulate, specific tire issues are common:

• Irregular wear: Heavy trucks are very sensitive to proper inflation, alignment, and balancing. Cupping, feathering, and shoulder wear are common symptoms of improper maintenance or mechanical issues.
  • Cupping: Often related to worn shocks or suspension components.
  • Feathering: Can indicate alignment issues (toe-in/toe-out).
  • Shoulder wear: Typically a sign of under-inflation (both shoulders) or over-inflation/excessive camber (one shoulder).
• Blowouts: While better tire technology has reduced this, blowouts can still occur due to overloading, under-inflation leading to heat buildup, road hazards, or aged/damaged tires. This is a significant safety concern for heavy trucks.
• Tire age degradation: Even with good tread, tires on heavy trucks can deteriorate over time due to UV exposure, heat, and repeated flexing. Commercial tires often have a recommended service life (e.g., 5-7 years for steer tires, potentially longer for drive/trailer) regardless of tread depth.
• Dual tire mating errors: On dual wheel configurations, it's crucial that mating tires have very similar circumference. Significant differences can lead to one tire scrubbing, premature wear, and increased fuel consumption.

Regular inspections, proper inflation based on load, timely rotations (where applicable), and correct balancing and alignment are key to maximizing tire life and ensuring safe operation of your Peterbilt 389.

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