A dually tire setup uses four tires on the rear axle—two per side—to spread heavy loads across more rubber and boost towing stability.
A dually tire isn’t a single standardized tire model. The term describes the configuration: a dual-rear-wheel (DRW) truck that runs two tires on each side of the rear axle instead of one. You’ll also hear it called dual tires, dual wheel, twin tires, or double tires. In U.S. usage, “dually” refers to the truck itself, not a special tire type.
The setup exists for one reason: load distribution. Two tires per side spread the weight across a larger contact patch, letting the axle carry more weight safely. That’s why you see duallys on heavy-duty pickups, box trucks, commercial trucks, trailers, and buses.
How a Dual-Rear-Wheel Setup Works
Think of the layout as two wheels in front and four in the rear, for a total of six tires on the vehicle. A standard single-rear-wheel axle has one tire per side; a dually has two. Factory-built DRW trucks need wider rear axles, longer axle shafts, different hubs, and wider rear fenders to accommodate the extra wheels and wider stance.
Each rear position carries two tires mounted side by side, usually with a small gap between them.
Benefits and Trade-Offs of Dually Tires
The payoff is real for heavy hauling. Duallys deliver higher payload capacity, better stability under heavy trailers thanks to the wider rear track, and safety redundancy—if one rear tire fails, the remaining tires can temporarily support the load.
But the trade-offs matter too. Duallys add width, weight, rolling resistance, and tire cost. They do not add engine power. The wider stance makes parking, lane positioning, and off-road maneuvering harder. Les Schwab notes duallys are common in construction, farming, and ranching because of heavy-load hauling needs—work trucks where those downsides rarely matter.
Dual Load Ratings and Matching Rules
Here’s the detail most owners miss: a tire’s load capacity differs between single and dual use. Dual tires share the load, so each one typically carries a lower rated maximum. Ignoring dual load ratings is a common mistake, especially when someone assumes any LT tire rated for single use is fine in a dual position.
The same pattern repeats across sizes:
| Tire Size | Single Max Load | Dual Max Load |
|---|---|---|
| 215/75R17.5 | 4,805 lb @ 123 psi | 4,540 lb @ 123 psi |
| 225/70R19.5 | 3,970 lb @ 110 psi | 3,750 lb @ 110 psi |
| 235/75R17.5 | 6,005 lb @ 127 psi | 5,675 lb @ 127 psi |
| 245/70R19.5 | 4,805 lb @ 120 psi | 4,540 lb @ 120 psi |
| 255/70R22.5 | 5,510 lb @ 120 psi | 5,070 lb @ 120 psi |
Dual tires must also be properly matched.
Common dually wheel sizes run 16-inch, 17-inch, and 19-inch, though some owners move to 20-inch or larger. A 235/85R16 is a popular fit on 6.5-inch-wide factory stock dually wheels, and if you’re shopping that size, our roundup of best 215 85r16 dually tires compares the top rated options side by side.
For maintenance, Discount Tire confirms a dual-wheel vehicle has four tires on the rear axle instead of two and offers rotation guidance for dually tires. Discount Tire’s dually tire guide walks through proper install and rotation procedures.
FAQs
How many tires does a dually truck have total?
A dually truck runs six tires total: two on the front axle and four on the rear axle, with two tires mounted side by side on each rear position. This configuration is sometimes described as “two wheels in front and four in rear.”
Can I rotate dually tires like a regular truck?
Rotation on a dually follows specific patterns that account for the four rear positions. Discount Tire provides guidance for dually-specific rotation to balance wear across all six tires evenly. Do not use a standard four-tire rotation pattern, as the rear dual positions wear differently.
Does a dually make a truck faster or more powerful?
No. Dual rear wheels add load capacity and stability, but they do not add engine power. In fact, the extra tires add weight and rolling resistance, which can slightly reduce acceleration and fuel economy compared to a single-rear-wheel version of the same truck.
References & Sources
- Discount Tire. “Dually Tires: Sizes, Loads & Rotation.” Explains dual-wheel configurations and maintenance guidance.
- Tire Rack. “How Do Dual Tire Fitments on Light Trucks Work?” Details redundancy benefits and load distribution on DRW vehicles.
- Michelin. “Dual Tire Truck Guidance.” Covers dual matching, load rating differences, and spacing requirements.