2024 Kenworth T680 — Tire Size & Pressure

Quick Answer: 2024 Kenworth T680 Tire & Wheel Specs

As a Class 8 heavy-duty commercial truck, the 2024 Kenworth T680 has drastically different tire requirements than consumer vehicles. Specs depend heavily on the gross vehicle weight rating (GVWR), axle configuration, and application (linehaul, regional, etc.). Below are the standard specifications for a typical over-the-road (OTR) T680 configuration:

• OEM Tire Size: 295/75R22.5 or 11R22.5 (Steer and Drive axles)
• Recommended Cold Tire Pressure (Front/Steer): 105 – 110 PSI (check door/B-pillar placard)
• Recommended Cold Tire Pressure (Rear/Drive): 95 – 100 PSI
• Bolt Pattern: 10 x 285.75mm (10 x 11.25 inches) — Hub Piloted
• Wheel Size: 22.5" x 8.25" (Standard) or 24.5" x 8.25" (Optional)
• Load Index / Speed Rating: Steer typically 144/141 (Load Range G) up to 16-ply 149/146 (Load Range H); Speed Rating L (75 mph) or M (81 mph)
• Spare Tire Size: Not typically equipped from the factory (roadside assistance or fleet-managed spares are standard)
• TPMS Frequency: 433 MHz (Bendix CVS / SmarTire systems)

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Tire Sizes by Application / Axle

Unlike passenger cars that have "trims," a Class 8 truck like the T680 is spec'd by the buyer for specific freight applications. Here are the most common tire sizes equipped from the factory:

Application / Axle	Common Tire Size	Wheel Size	Load Range
Standard Linehaul (Steer)	295/75R22.5	22.5" x 8.25"	G or H (14-16 Ply)
Standard Linehaul (Drive)	295/75R22.5	22.5" x 8.25"	G (14 Ply)
Heavy Haul / Regional (Steer)	11R22.5 or 11R24.5	22.5" or 24.5"	H (16 Ply)
Heavy Haul / Regional (Drive)	11R22.5 or 11R24.5	22.5" or 24.5"	G or H (14-16 Ply)
Wide-Base "Super Singles" (Drive)	445/50R22.5	22.5" x 14.00"	L (20 Ply)

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Recommended Replacement Tires

When spec'ing replacement tires for a linehaul Kenworth T680, tread life, fuel efficiency (SmartWay verification), and casing retreadability are key. Here are top-tier recommendations for commercial applications:

1. Michelin X Line Energy Z (Steer) – Premium Tier
   • Known for exceptional fuel efficiency, even wear, and one of the best casings in the industry for retreading. Highly recommended for long-haul T680s.
2. Bridgestone R213 Ecopia (Steer) – Premium Tier
   • Features directional tread for wet traction and NanoPro-Tech polymer compound to reduce rolling resistance.
3. Goodyear Endurance LHD (Drive) – Mid-to-Premium Tier
   • A closed-shoulder drive tire that offers excellent mileage and grip for over-the-road conditions.
4. Yokohama 712L (Drive) – Mid-Tier
   • An excellent cost-per-mile alternative offering deep tread (30/32nds) for regional and long-haul operations.

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When to Inflate to Max Load PSI

As a heavy-duty Class 8 truck, the 2024 Kenworth T680 operates under varying load conditions.

• Steer Tires: The steer axle weight stays relatively constant (usually around 12,000 to 13,200 lbs depending on the engine). You should almost always maintain the steer tires near their maximum placard pressure (typically 105 to 110 PSI for Load Range G, or up to 120 PSI for Load Range H if running heavier axles) to prevent irregular wear and ensure optimal handling.
• Drive Tires: If you are consistently hauling maximum gross vehicle weight (80,000 lbs combined), drive tires should be inflated to the higher end of the placard specification (typically 100 PSI). Running empty or bobtailing at max PSI can lead to a harsh ride and center-tread wear, but fleet mechanics generally recommend keeping pressures at max-load spec to account for sudden reloading and to minimize casing fatigue.

Note: Always consult your fleet's tire maintenance policy and the tire manufacturer's load-and-inflation tables based on your actual scale weights.

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Lug Nut Torque & Pattern

Proper wheel torque is a critical safety item on commercial trucks to prevent wheel-off incidents.

• Bolt Pattern: 10-Lug, 285.75mm bolt circle.
• Wheel Type: Hub-Piloted (M22 x 1.5 two-piece flange nuts).
• Lug Nut Torque: 450 to 500 ft-lbs.
• Torque Sequence: Always use a star/crisscross pattern.
• Re-torque: Hub-piloted wheels must be re-torqued after the first 50 to 100 miles of operation following a wheel removal.

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Common Tire Issues for This Vehicle

1. Irregular Steer Tire Wear (Cupping/River Wear): A common issue on all Class 8 trucks, including the T680. Often caused by slight toe misalignment, worn kingpins, or worn shock absorbers. Regular alignment (at least once a year or every 100,000 miles) is crucial.
2. Underinflation: Because commercial duals mask low pressure in a single tire, drivers may fail to notice a slow leak. This leads to casing failure and blowouts. Relying heavily on the factory Bendix TPMS and performing daily pre-trip thumper/gauge checks is vital.
3. Tandem Drive Tire Scrubbing: If the rear tandem axles are out of alignment, the truck will "dog track," causing diagonal wear across the drive tires and reducing fuel economy.

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