Here’s Why Your Truck Tire Has 2 Valve Stems

There are several applications where dual valve stems are visible on truck wheels. If the truck has dual wheels on the rear axle, there are two tires mounted side by side, and the valve stem of the inside tire will protrude through the rim of the outside tire, allowing both tires to be checked for pressure and to pump them up.

Some truck wheels are fitted with two valve stems from pumping air into or deflating the tire while checking the air pressure at the other valve.

The tire pressures must be lowered before going off-road, and when going back onto the tarmac, the pressure must be increased again. Two valve stems per tire help the driver monitor the pressure while using the other valve to increase or decrease the pressure.

There are several applications where wheel rims are fitted with two valve stems, or two valve stems visible at the outside rim face. Let’s look at these in more detail.

When Will Two Valve Stems Visible On The Side Of A Tire?

Performance car tires are often filled with nitrogen gas. The gas molecules in the nitrogen gas are much smaller than those in normal air and result in the tire running cooler. Cooler tires will perform better in the extreme conditions of racing. The tires will wear more slowly and also retain better grip.

The rims of performance cars are often fitted with two valves. The normal air is evacuated via one valve while the nitrogen gas is pumped in via the second valve. The alternate valve can also accurately monitor the pressure as the nitrogen gas is pumped into the tire.

Dual Rear Wheel Trucks, often called Dually Trucks, are heavy-duty pickup trucks with two rear wheels on each side of the rear axle. The load rating of the four tires on the rear axle will increase the truck’s ability to carry heavier loads and provide additional stability to the truck in operation.

On Dually Trucks, the wheel on the inside has a valve extension that protrudes through a gap in the rim of the outside wheel, enabling the inside tire to be pressure checked and inflated.

Lowering the tire inflation on off-road truck tires is one of the golden rules of off-road driving. For various surfaces, different tire pressure is essential for optimal grip in off-road conditions. Going back onto the highway after completing an off-road adventure necessitates adjusting the tire pressures to normal.

Some off-road wheel rims are manufactured with two valve stems for each tire. The two-valve stems are to facilitate the process of deflating or inflating the tires in the fastest and most accurate way possible. The electric air pump is screwed onto one valve stem, and a tire pressure gauge is attached to the other valve stem, allowing the driver to pump the tires and simultaneously check the tire pressure.

Where the wheel rims only have one valve stem, the process of screwing the air pump hose to the valve and unscrewing it again to check the tire pressure is time-consuming and inefficient. 

Which Trucks Will Have Two Valve Stems Visible?

Long haul trucks mostly have single steer tires on the front axle and dual drive tires on the drive axles. Such trucks are called 6×6 tractors. The truck has six tires fitted, two for steering and four tires on the rear-drive double-axle. The truck trailer is also equipped with dual tires on each side of the axles to carry the load.

The objective of having four tires on each load axle is to assist with the truck’s load-carrying capacity and serve as a safety redundancy measure. On duel tire arrangements, tires on the inside of the axle have to be pressure checked and inflated by a valve stem, routed to be visible at the rim of the outside tire.

The two valves visible at the outside rim serve two tires separately. The dual tire arrangement on trucks assists when a tire bursts or loses air pressure, and the second tire will still be able to safely carry the load and assist with the rig’s control.

Off-road vehicles can be fitted with wheel rims that have two valve stems per wheel. The dual valve stem arrangement is convenient for the deflation and inflation of tires, as is often required by off-road conditions.

When deflating the tires, an air pressure gauge is fitted to the one valve, while the other valve is used to bleed off the air, resulting in a fast, accurate deflation of all tires within a short time.

Off-road drivers’ portable electrical air pumps to inflate tires must be screwed onto the valve stem. When the wheel only has one valve stem, screwing the air pump hose on and off the valve stem to pump and check the air pressure is time-consuming.

Wheel rims fitted with two valve stems are convenient for use in off-road driving, which requires deflation and inflation for all vehicle tires. The dual valve stem arrangement is convenient to speed up the process of inflation or deflation. An air pressure gauge is fitted to one valve while the other has the air pump hose screwed on during the inflation process.

Dual Valves For Performance Cars and Agri-Vehicles

Tires are not always filled with compressed air as a filled medium. The use of nitrogen gas in performance cars is quite common. The smaller nitrogen gas molecules generate less heat inside the tire during operating conditions. The tires run cooler and can perform better for longer due to the lower operating temperature. Duel valves are used to evacuate the air and pump in the nitrogen.

The tires on agricultural vehicles are often filled with water to provide more weight on the ground. The dual valve arrangement on agricultural tires is used similarly as with the nitrogen gas-filled tires. One valve is used to evacuate air from the tire, while the second valve pumps water into the tire.


Trucks are often fitted with dual valves per tire or two valves visible at the rim of the outside tire. In the case of off-road trucks, these double valve rims assist with the deflation and inflation process.

Dual tire arrangements such as on Dually Trucks has the valve for the inside tire will be visible on the inside of the rim for the outer tire.

Recent Posts