2020 Isuzu NQR Tire Size, Pressure & Wheel Specs

As an ASE-certified master technician, I’ve serviced countless medium-duty commercial trucks, and the Isuzu NQR is a staple in the delivery and fleet world. Built to handle a Gross Vehicle Weight Rating (GVWR) of up to 17,950 pounds, the 2020 Isuzu NQR requires robust, commercial-grade tires to maintain safety, fuel efficiency, and load-carrying capacity.

Below is your ultimate reference guide for the 2020 Isuzu NQR tire and wheel specifications.

Quick answer

• OEM tire size: 225/70R19.5 (14-ply / Load Range G)
• Recommended cold tire pressure: 95 PSI front / 95 PSI rear (unloaded/standard payload; check door placard for your exact upfit)
• Max load tire pressure: 110 PSI front/rear (for maximum GVWR)
• Bolt pattern: 6x222.25mm (6x8.75")
• Wheel size: 19.5" x 6.0" (Steel or optional Aluminum)
• Load index/speed rating: 128/126 L or M
• Spare tire size: 225/70R19.5 (Full-size matching spare)
• TPMS frequency: N/A (Standard medium-duty commercial trucks like the NQR do not come with factory light-truck TPMS sensors; they utilize high-pressure commercial metal valve stems, though aftermarket fleet TPMS kits are common).

Tire sizes by trim

Unlike passenger vehicles, medium-duty trucks like the Isuzu NQR keep things simple. Whether you have the Standard Cab or the Crew Cab, the chassis rolls on the same heavy-duty 19.5-inch commercial tires.

Recommended replacement tires

When outfitting a commercial truck, tire choice dictates your cost-per-mile. You need high-scrub resistance for urban delivery routes and excellent all-position wear. Here are three highly recommended options:

1. Michelin XZE (Premium Tier) - Arguably the industry standard for commercial regional and urban transport. Offers exceptional tread life, excellent wet traction, and highly retreadable casings.
2. Goodyear G661 HSA (Mid-to-Premium Tier) - A heavy-duty highway steer and all-position tire designed specifically for high-scrub applications like delivery box trucks. Features a wear-resistant compound.
3. Continental Hybrid HS3 (Mid-Tier) - Delivers a great balance of fuel efficiency and mileage. A fantastic choice for fleets looking to lower operational costs without sacrificing safety.

When to inflate to max load psi

The 2020 Isuzu NQR is a heavy-duty workhorse. Because it functions as a cab-forward chassis for box trucks, flatbeds, and dump bodies, its weight fluctuates drastically.

• Standard driving (Empty or light payload): Running at the placard pressure (often around 90-95 PSI) ensures a smoother ride and prevents center-tread wear.
• Max Load PSI (110 PSI): You must inflate the tires to the maximum cold pressure of 110 PSI when approaching the vehicle's maximum GVWR (17,950 lbs) or maximum rear axle weight rating. Underinflating a fully loaded box truck causes excessive sidewall flexing, leading to rapid heat buildup and catastrophic blowouts. Always check tire pressures with a calibrated commercial truck tire gauge before dispatching a loaded truck.

Lug nut torque & pattern

Proper wheel torque is critical on dual-rear-wheel (DRW) commercial trucks. A loose wheel can shear studs, while an over-tightened wheel can warp the brake rotors or stretch the threads.

• Bolt Pattern: 6x222.25mm (commonly referred to as 6x8.75")
• Lug Nut Torque: ~347 lb-ft (470 Nm). Always verify with your specific owner's manual or upfitter documentation.
• Procedure: Because of the immense torque required, use a heavy-duty 3/4-inch or 1-inch drive torque wrench. Tighten in a star crisscross pattern. After a wheel replacement, retorque the lug nuts after 50 to 100 miles of driving to ensure they have properly seated against the dual wheels.

Common tire issues for this vehicle

Operating an Isuzu NQR day in and day out exposes the tires to severe conditions. Watch out for these common issues:

• Steer Tire Cupping/Rivering: Due to the cab-forward design, the front suspension handles a significant amount of weight. Worn kingpins, loose tie rods, or misaligned toe settings will quickly cause the outside edges of the front steer tires to cup or feather.
• Dual Tire Scrubbing: If the rear dual tires are mismatched in air pressure by even 5-10 PSI, the smaller (lower pressure) tire will be dragged along by the larger tire. This causes rapid, irregular wear. Always run matched pressures, matched tread depths, and matched tire brands on dual positions.
• Curb Damage: NQR delivery trucks live in urban environments. The passenger-side sidewalls frequently suffer from curb abrasions. Inspect the sidewalls weekly for deep cuts that expose the steel casing cords.

Need new tires? Find a trusted shop on Repairius.