2014 Kenworth T680 Tire Size, Pressure & Wheel Specs

As an ASE-certified master technician with years of experience working on Class 8 heavy-duty trucks, I know that tire maintenance on a 2014 Kenworth T680 is crucial for maximizing fuel efficiency, ensuring safety, and minimizing downtime. The T680 is an aerodynamic workhorse, and outfitting it with the correct rubber and keeping it properly inflated makes a massive difference in your bottom line.

Here is your comprehensive guide to the 2014 Kenworth T680 tire specifications, pressures, and torque requirements.

Quick answer

• OEM tire size: 295/75R22.5, 11R22.5, or 11R24.5 (varies by fleet spec and application)
• Recommended cold tire pressure (door placard): 105–110 PSI Front (Steer) / 95–100 PSI Rear (Drive), depending on axle weight ratings.
• Bolt pattern: 10-lug hub-piloted (10x285.75mm)
• Wheel size: 22.5" x 8.25" or 24.5" x 8.25"
• Load index/speed rating: Load Range G (14-ply) or Load Range H (16-ply) / Speed Rating L (75 mph) or M (81 mph)
• Spare tire size: Not equipped as standard (fleets generally rely on road service, but if equipped, it is a matching full-size steer or drive tire)
• TPMS frequency: 433 MHz (commonly Bendix SmarTire or aftermarket systems)

Tire sizes by configuration

While standard passenger vehicles have "trims," Class 8 trucks like the T680 are custom-ordered based on their intended application. Here are the most common configurations and their typical tire sizes:

Recommended replacement tires

When replacing tires on your Kenworth T680, you need tires built for longevity, low rolling resistance, and retreadability. Here are some of the best options broken down by price tier:

• Premium: Michelin X Line Energy Z (Steer) / X Line Energy D (Drive) — Excellent fuel efficiency, long tread life, and arguably the best casing for retreading.
• Premium: Bridgestone R213 Ecopia (Steer) / M713 Ecopia (Drive) — High tier fuel-efficient tires designed to combat irregular wear.
• Mid-Tier: Goodyear Endurance series — Great durability and strong performance in both linehaul and regional applications.
• Budget-Friendly: Yokohama 101ZL or Double Coin RT500 — Reliable performance at a lower upfront cost, though casings may not yield as many retread lifecycles as premium brands.

When to inflate to max load psi

Because the 2014 Kenworth T680 is a Class 8 heavy-duty truck, proper tire pressure is dictated by the actual load carried on the axles.

You should inflate your tires to the maximum load PSI (often 110–120 PSI for Load Range H tires) only when your axles are loaded near their maximum Gross Axle Weight Rating (GAWR). For example, if your steer axle is carrying 12,000 to 13,200 lbs, you will likely need 110 PSI in the steer tires. If you run empty or light, running at max PSI will cause the tires to crown, leading to rapid center tread wear and a harsh ride. Always consult the tire manufacturer's load and inflation tables to match your actual scaled weight to the proper pressure.

Lug nut torque & pattern

Class 8 wheel-ends require strict adherence to torque specifications to prevent wheel-off conditions.

• Pattern: 10-lug hub-piloted (10x285.75mm)
• Lug nut size: Usually 33mm hex nuts
• Torque specification: 450–500 ft-lbs
• Important Note: Do not use lubricants on the threads or the face of the nut, but two drops of oil between the nut and the integrated washer is recommended. Always retorque wheel nuts after 50 to 100 miles following a wheel installation.

Common tire issues for this vehicle

• Irregular Steer Tire Wear: The aerodynamic design of the T680 places specific demands on the steer axle. Cupping or river wear (wear along the edge of a rib) is common if alignment is out of spec, or if worn shock absorbers allow the tire to bounce.
• Drive Tire Scrubbing: In tandem axle setups, the rear-most drive tires often scrub during tight turns, causing accelerated shoulder wear. Keeping tandem axles properly aligned (thrust angle) minimizes this.
• Underinflation Blowouts: Inboard drive tires are notoriously difficult to check for pressure without proper valve extensions or TPMS. Running an inboard dual underinflated causes the sidewall to flex excessively, build up heat, and eventually blow out, often taking out the mudflap and quarter fender with it.

Need new tires? Find a trusted shop on Repairius.