2014 Isuzu NPR Tire Size & Pressure Guide

As an ASE-certified master technician, I’ve serviced countless commercial trucks over the years, and the 2014 Isuzu NPR is a staple in the medium-duty cabover world. Whether you're running a landscaping fleet, a delivery box truck, or a flatbed, your NPR’s tires are its literal foundation. Running the wrong tire size, neglecting pressure checks, or mis-torquing the dually rear wheels can lead to expensive blowouts and downtime.

Here is your comprehensive spec guide for the 2014 Isuzu NPR tire and wheel systems, brought to you by Repairius.com.

Quick answer: 2014 Isuzu NPR Specs

Here are the essential factory specifications for a standard 2014 Isuzu NPR:

• OEM tire size: 215/85R16 (Load Range E / 10-ply)
• Recommended cold tire pressure: 80-85 PSI front / 80-85 PSI rear (varies slightly by upfit and exact GVWR; always check the door jamb or B-pillar placard)
• Bolt pattern: 6x222.25mm (6x8.75")
• Wheel size: 16x5.5K or 16x6.0J (Dually setup in the rear)
• Load index/speed rating: 115/112 L (2,680 lbs single / 2,470 lbs dual capacity per tire)
• Spare tire size: Full-size matching (215/85R16)
• TPMS frequency: N/A (As a commercial Class 3/4 truck, the 2014 NPR did not come standard with passenger-style 315 MHz or 433 MHz TPMS sensors, though aftermarket systems are commonly installed).

Tire sizes by trim

The Isuzu NPR platform (including Gas, Diesel, and HD variants) keeps things incredibly simple. Nearly all configurations use the same heavy-duty 16-inch commercial tire to support their 12,000 to 14,500 lb GVWRs.

(Note: Always verify your specific truck's load requirements, as chassis-cab upfits can change weight distribution).

Recommended replacement tires

When replacing tires on a commercial cabover, you want commercial highway rib tires for the steer (front) axle, and either rib or traction/drive tires for the rear duals. Here are my top recommendations based on durability and cost-per-mile:

1. Michelin XPS Rib (Premium) An all-steel casing construction makes this the gold standard for commercial delivery. Incredible tread life and retreadability.
2. Firestone Transforce HT2 (Mid-Range) A very popular OEM and fleet replacement tire. It offers great chip-and-tear resistance and handles heavy payload shifts well.
3. Yokohama RY023 (Mid-Range) A fantastic commercial steer/all-position tire specifically favored by many cabover operators for its resistance to uneven wear.
4. Sailun Terramax H/T or S637 (Budget) For fleets on a strict budget, Sailun offers a surprisingly robust heavy-duty casing that punches above its price tier.

When to inflate to max load psi

Because the 2014 Isuzu NPR is a heavy-duty commercial truck, tire pressure management is critical. The sidewall of a 215/85R16 Load Range E tire lists a maximum cold pressure of 80 PSI (sometimes 85 PSI depending on the exact commercial tire spec).

You should inflate to the maximum placard PSI when:

• You are carrying loads at or near your vehicle's Gross Vehicle Weight Rating (GVWR) or Gross Axle Weight Rating (GAWR).
• Your box is fully loaded with heavy materials (e.g., liquids, palletized freight, soil).
• Tech Tip: If you run the truck completely empty (like a bare chassis), you can safely drop the rear tires to around 60-65 PSI to improve ride quality and prevent center tread wear, but you must air them back up before taking on a load.

Lug nut torque & pattern

The 2014 Isuzu NPR features a 6-lug, dual-rear-wheel configuration (6x222.25mm).

• Lug Nut Torque: Factory specification is generally 175 lb-ft for the standard NPR M16 studs. (Heavier NQR/NRR models with M20 studs require significantly more, around 362 lb-ft).
• Torque Sequence: Always use a standard star/crisscross pattern.
• Re-torque: On dual-rear wheels, the inner and outer wheels must seat properly. Always re-torque the lug nuts after 50 to 100 miles of driving following a wheel removal.

Common tire issues for this vehicle

1. Inner Dual Neglect: The most common issue on Isuzu cabovers is the inner rear tire running low on pressure because the valve stem is hard to reach. This causes the inner tire to overheat and blow out, taking the outer tire with it. Install valve stem extensions!
2. Steer Tire Cupping: Cabovers put a lot of weight over the front axle. If the kingpins get worn or the toe alignment is out, the front tires will cup and wear unevenly very quickly.
3. Overloading: Many operators treat the NPR like a much larger truck. Exceeding the tire's load index will cause casing separation and sidewall bubbling.

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