Belt Driven Air Compressors vs. Direct Drive Air Compressors

September 17, 2021

Vehicle integrated air compressors have revolutionized mobile air power. These innovative air compressors use vehicles’ existing power sources to provide compressed air on-demand, anywhere the vehicle goes. They are also significantly lighter and take up little to no deck or cargo space, which is a huge advantage compared to traditional air compressors.

VMAC’s vehicle-integrated mobile air compressors typically come in two styles: belt driven air compressors and direct drive air compressors. Each style connects to a different power source and has its benefits, which we will outline below.

underhood-air-compressorBelt Driven Air Compressors

VMAC’s UNDERHOOD™ product line consists of several belt driven air compressors that mount within the vehicle’s engine compartment. Belt driven air compressors use pulleys to connect the air compressor to the engine, using the vehicle’s engine to power the air compressors.

UNDERHOOD air compressors are designed and engineered for specific vehicles and model years because of their placement location and must be compact and lightweight to fit. Since 1996, VMAC is the only manufacturer to create a powerful air compressor that is small enough to fit within the engine compartment.

VMAC’s engineers also work closely with OEMs each year to ensure the UNDERHOOD will fit within new trucks, making tweaks and adjustments as required, and to maintain OEM warranties. As a result, UNDERHOOD belt driven air compressors are available for the most popular Ford, RAM, GMC, and Chevrolet work trucks.

Belt Driven Air Compressor Benefits

  • Highly convenient mobile air
  • Compact & lightweight
  • Frees up to 80 cubic feet on truck bodies
  • Decreases GVW by up to 1,900 lb
  • No additional engine to maintain
  • Frees up hitch space
  • Works in extreme climates
  • Up to 140 CFM of compressed air at 100% duty cycle (dependent on vehicle application and engine RPM)

Learn more about UNDERHOOD air compressors here.

Direct Drive Air Compressor

DTM-Air-CompressorDirect drive air compressors have many of the same benefits as belt driven air compressors, including compact and lightweight designs, but this new technology has a few additional advantages.

VMAC’s DTM direct drive air compressors connect directly to the transmission’s PTO port, which provides power to the air compressor. They have minimal moving parts, are straightforward to install, and are simply the best PTO air compressor solution available today.

Like belt drive air compressors, direct drive air compressors need to be designed for individual trucks. There is so little space in the mounting area that engineers must carefully consider every fraction of an inch, finding the perfect spot for the compressor. VMAC works closely with OEMs during this process to ensure a proper fit and maintain vehicle warranties.

VMAC also offers a direct drive air compressor with a hydraulic power option, called the DTM70-H. This incredibly innovative system can provide variable air and steady hydraulics simultaneously. As a result, operators can run both their crane and air compressor simultaneously, getting jobs done faster.

VMAC’s DTM70 and DTM70-H air compressors are available for popular Ford and RAM work trucks.

Direct Drive Air Compressor Benefits

  • Highly convenient mobile air
  • Compact & lightweight
  • Frees up to 80 cubic feet on truck bodies
  • Decreases GVW by up to 260 lb
  • No additional engine to maintain
  • Hydraulic pump option (DTM70-H)
  • Works in extreme climates
  • Up to 70 CFM of compressed air at 100% duty cycle

Learn more about VMAC’s DTM70 and DTM70-H systems here.

Is Belt Drive or Direct Drive Better For Air Compressors?

Both belt drive and direct drive air compressors have proven to be reliable, high-quality methods of powering compressed air systems. The choice for one over the other typically comes down to a few factors:


Because vehicle-integrated air compressors are designed for specific truck model years, choosing a compatible air compressor is crucial. In some cases, choosing one style over the other is automatically determined by which option is compatible. However, additional factors should be considered when trucks are compatible with both belt drive and direct drive systems.

To find out which vehicle-integrated air compressors are compatible with your work truck or van, view VMAC’s Application Lists.

CFM Requirements

For applications that require more than 70 CFM, the UNDERHOOD 150 is an excellent option. This model provides up to 140 CFM of continuous air on demand. If less than 70 CFM is required, both belt drive and direct drive solutions can serve that need.

Hydraulic Requirements

If an application requires both hydraulic power and air power, the DTM70-H is usually the way to go. Running simultaneous hydraulics and compressed air is a game-changer that makes work faster and more efficient.

 Installation and Support

installation and support are always important factors in any equipment decision. VMAC Dealers provide sales, service and installation, so we always recommend working with our dealers to discover which solution best suits all of your needs. Find a local VMAC dealer here to get quotes!