Diesel air compressors are used for construction, mining, or manufacturing companies and are used to power all sorts of tools and equipment.

For example, mobile mechanics use diesel compressors that produce 10-20 c.f. per minute. On the other hand, municipal utilities will use diesel air compressors that produce 250 c.f. per minute. Heavy-duty diesel compressor is generally considered better than gas-powered compressors because they run at a lower rpm. 

Portable diesel air compressors are most commonly found in use in the construction industry. They work well with large tools, such as 60-pound jackhammers, vertical or horizontal grinders, and impact wrenches. 

They are also used for OTR tire inflation for trucks and RVs. These compressors weigh up to 2,000 pounds, so they are usually either vehicle- or skid-mounted, or towed behind a vehicle. They usually have reciprocating air ends or come with a rotary screw.

This makes them more reliable since they don’t wear down as quickly. They are more fuel-efficient resulting in lower overall fuel costs. Plus, with the higher flashpoint (100-130 degrees compared to the -45 degrees Fahrenheit flashpoint of gasoline), diesel is inherently safer than gas.

Air compressors are one of the most important, large investments that you need to make for your workshop or over-the-road use.

Based on our research, the most powerful diesel air compressor is Atlas Copco XAS 185, it provides the highest HP and the highest SCFM rating. The most expensive diesel air compressor is the Sullair 185 with a retail price of $32,000.

We have compiled five of the best diesel air compressors available, including their primary features, pros and cons, and prices. We have also included buying tips so you can make the most informed decision about which model is best for your purposes.

Best Diesel Air Compressors

Product Name (Max 175 PSI)CFMPriceHorsepower
Champion R Series 20 SCFM$7,628.639.1 HP
Kaeser M17 Mobile35 SCFM $10,82517.4 HP
Atlas Copco XAS 185185 SCFM$23,45049.6 HP
Quincy QP-1035 CFM$5,79910 HP
Sullair 185 185 CFM$32,00010 HP

1.Champion R Series (W/ Kohler Diesel Engine) – Tank Mounted 

The Kohler engine helps Champion beat out the competition.  An air compressor without a working engine is basically scrapped metal.  So all things being equal, the engine wins out.

Having an electric start is a great way to begin your workday.  Loadless starting via a governor-type centrifugal unloader helps extend the engine life.  The pneumatic throttle control makes controlling speed easier, also a plus.  

You don’t have to worry about blown head gaskets with this Champion due to the gasketless cylinder design. 

Multi-finned cylinders and the combination of two compression rings and one oil control ring deliver air efficiently and offer lower operating temperatures.

The enclosed belt guard is a safety feature that we like.

Essential Product Specs include:

  • Capacity.  20.1 CFM @ 175 PSI
  • Max Pressure.  175 PSI
  • Engine HP:  9.1 Kohler
  • Oil Capacity:  1.6 liters
  • Fuel Tank:  5.28 Qts
  • Air Tank:  80 gallons

The Champion 20.1 also sells a unit with a 30-gallon air tank. Ordering Tip:  You will need a starter battery as Champion does not include one.  

2.Kaeser M17 Mobile Air Compressor – Skid Mounted

Although these are the smallest of the Kaeser Mobilair compressors, they still pack quite a punch.  The 17.4 Honda engine in the M17 is powerful enough for breakers and impact wrenches and borers.   

The M17 has 12V electrical connection that provides power for the optional air aftercooler fan.  The connection discharges condensation, and the lightweight support frame (33 pounds) has fixed connections.  Connect and cool—what could be easier?

Standard features include a Honda engine, one-touch electric start, easy-start because the compressor and engine are disengaged, and quiet operation due to vibration isolation.  Also impressive is the 4-micron air intake filter to protect the compressors in nearly any construction environment.

Essential Product Specs include:

  • Capacity.  35 CFM @ 217 PSI
  • Max Pressure.  175 PSI
  • Engine HP:  17.4
  • Fuel Tank:  5.3 gallons
  • Weight 450 lbs.

3.Atlas Copco XAS 185

The Atlas XAS 185 is considered one of the top air compressors by many in the industry.  Atlas Copco manufacturers one in three air compressors sold worldwide, and the company has a long history of first—first portable air compressor, first air-cooled diesel compressor, and first portable screw compressor, to name just a few.

Instead of resting on its laurels, Atlas Copco continues to improve the mobile air compressors.  The familiar HardHat © canopy protects your compressor and the many features under the canopy.

A high-performance Kubota engine powers the 185, and the fully automatic step-less speed regulator adjusts engine speed to air demands.   Atlas Copco has increased the altitude capability of the 185 from previous models.

Worried about power and fuel?  No problem.  Since the engine directly drives the air element, there is no gearbox, allowing the compressor to produce more air with less horsepower.

Concerned about excessive downtime?  The 185’s cooling system can operate continuously in temperatures up to 120˚ Fahrenheit.

Controls are centralized to make it easier to operate and monitor the compressor.  The two-stage air filter keeps the engine lasting longer by keeping dirt and dust out.

Essential Product Specs include:

  • Max Pressure:  175 psi
  • Engine HP:  49.6
  • Oil Capacity:  1.8 gallons
  • Fuel Tank:  20 gallons

Optional items include a cold-weather package, hydraulic or electric trailer brake package, extended drawbar, and exterior front toolbox.

The XAS 188 doesn’t just look good, but it provides high-quality, useful features.  One doesn’t need to have an air compressor that looks good, but good looks and high-performance sound like a winning combination.  

4.Quincy QP-10 – Reciprocating Diesel Air Compressor

If you need an air compressor that can handle tougher 175 PSI applications, the Quincy QP-10 is up to the job.  Unlike compressors that use splash lubrication, where a dipping device splashes oil through the crankcase is it rotates, the QP is pressure lubricated.  A pressure lubricated compressor uses a pump to continuously send oil through the crankcase.

Pressure-lubricated compressors tend to last up to 15% longer than splash-lubricated pumps, making Quincy compressors an excellent value.  The combination of heavy-duty cast iron cylinders and aluminum head produces an efficient compressor. 

The aluminum head allows for efficient heat dissipation while the rigid cast iron produces more power.  The fin and tube intercooler and oversized oil reservoir reduce the risk of overheating.

Essential Product Specs:

  • Maximum Pressure:  175 psi
  • Engine Horsepower:  10 
  • Fuel Capacity:  1.72 gallons
  • Air Tank:  30 gallons

If you want a durable, hard-working, no-nonsense air compressor backed by a 7-year warranty, the Quincy QP-10 is worth a look.    

5. Sullair 185 – Best Portable Diesel Air Compressor

The Sullair 185 runs on a Kubota 1803 Diesel engine and can get you to the job quickly due to the highway-towable running gear.  Once there, you can get up to 10 hours of runtime due to the oversized 27-gallon fuel tank.

Sullair prides itself on the light and compact design of its portable air compressors, and the Sullair 185, at 59.2 inches wide and 130.8 inches long, delivers on that goal.  

The feature that makes Sullair compressors stand out is the proprietary rotary screw gas ends.  Because the primary moving parts are two rotors, there is little wear on the engine.  This design also reduces maintenance requirements.  These bullet-proof engines have been known to run for 100,000 hours.  

The open engine design offers easy access to filters, lubricants, and other routine maintenance items.  The 185 has consolidated the fuse and relay boxes, and access to air filters and oil dipstick has been improved.  

Sullair realizes that compressors need to work in various weather conditions, so the 185 ships with AWF® All-weather Compressor Fluid to keep your compressor working regardless of the weather conditions. 

Sullair 185 series

Essential Product Specs:

  • Maximum Pressure:   125 psi
  • Engine Horsepower:  49
  • Fuel Capacity:  27 gallons
  • Oil Capacity:  7.3 quarts

When you get to your work site, the 12-volt key start will get you going quickly, and the large toolbox will let you get to your tools quickly.

6. Atlas Copco DrillAir Range

For those who need a high volume of compressed air, the Copco DrillAir Range provides compressors for a variety of drilling applications.   The DrillRange lets you drill with 35 bar pressure at 34.8 meters³ per minute.  The Dynamic Flow Boost® allows for higher flow (up to 39 meteres³ per minute when flushing or refill of drill stems.   

Higher fuel consumption per hour is compensated by a lower cost per meter.  The DrillAir compressors help lower maintenance expenses due to the Scania engine and the triple-layer protection coating of the bodywork. 

All the DrillAir Models can drill 500 meters per day and carry the compressor on a single truck due to the short frame.  The Y35 can tackle two 4.5-inch 500  meter deep geothermal wells in a day while consuming less than 2.2 liters of fuel per meter.

Models range from the V39, which is ideal for foundation drilling, to the Y35, which is used for deep geothermal drilling. Models between those two ranges can handle waterwell and ground engineering. 

The larger XAH 1066 is housed in a 20-foot ISO – CSC – DNV compliant container for secure handling while being transported and installed.  The forklift slots make it easy to move the unit.  The offshore unit can be stacked up to 8 feet high while the standard unit has a 3-storage maximum.  

Numerous safety features are built into the XAH.  A built-in ladder system provides easy access to the roof.  The door latches have door safe-hooks to keep them from accidentally closing.  Emergency stop buttons are easily accessible, and spark arresters prevent heated particles from exiting the exhaust pipes. 

To prevent engine overrun, the unit has over-speed protection and an intake shutdown. The XAH 1066 has separate access doors for each of the CAT C13 engines so that you can choose to run only one.  

The XAH 1066 has tons of features that make maintenance easier.  For example, access doors for servicing the engine and internal components are large, and the pressure regulators can be easily accessed.  The service drains are centralized so the draining can be done quickly and easily. 

A comprehensive maintenance system lets you know when the machine needs servicing and maintenance service kits have all the needed parts for servicing the unit in one place.  

7. Vanair Viper D80

This tough diesel compressor can run a 90-pound jackhammer but compact enough to fit into a small pickup bed.  The Vanair runs on a liquid-cooled Kubota Tier 4 certified engine with auto shut off and start.  

Key features include automatic variable speed control, a cooling baffle for ventilation and noise reduction, and a direct drive compressor.

We really like the focus on safety:

  • Automatic shutdown on compressor high pressure, engine high-temperature, and low engine oil pressure
  • Automatic blowdown on shutdown
  • Pressure valves for minimum pressure and air pressure relief

If you are looking for a skid-mounted air compressor without also having to cough up cash for a larger pick-up, this is one worth checking out.

Essential Product Specs include:

  • Capacity:  Based on Model Number
  • Max Pressure:  125/125/100
  • Engine HP:  24.8
  • Oil Capacity:  1.6 liters
  • Fuel Tank:  9 gallons

Some options to consider include a cold-weather package, an air aftercooler, and remote fuel tank options.  

8. Doosan HP 915WCU-T4F

The Doosan HP 915 is a heavy-duty, tandem axle portable compressor ideal in construction, abrasive blasting, and mining operations.  

Doosan redesigned the enclosure to create a more accessible large air compressor.  Panels on all sides of the compressor allow for easy access to service components.  The rear panel door makes heat exchanger cleaning simple.  Easy access to operator controls can be gained due to the double-door design at the front of the unit. 

The Doosan compressor can be efficiently operated due to several features, including a ViewPort control panel that provides detailed preloaded resources such as manuals, maintenance schedules, and information about spare parts.  Operators can access data on electronic devices through built-in Wi-Fi.

Important Specs include:

  • Free Air Delivery:  915 cfm
  • Operating Pressure:  150 psi
  • Pressure Range:  80-175 psi
  • Fuel Capacity:  128 gallons

An optional system for cleaner air, the IQ System, features an onboard aftercooler.  The system also includes both dual-filtration and condensate removal systems that can handle the toughest jobs.  A 6-cylinder Cummins QSX15 powers this compressor.  Due to the 198-gallon onboard fuel capacity, the HP 1600 delivers 8 hours of continuous runtime at 100% load.

  • Free-Air Delivery: 1600 cfm
  • Operating Pressure:  150 psi
  • Pressure Range:  80-150 
M27 Kaeser

Diesel Air Compressors Vs. Gas Air Compressors 

When considering a diesel air compressor, one must ask is a Diesel Compressor Superior to a Gas Compressor? The short answer is that a diesel compressor is superior to gas compressors. Let’s look at why frequent users of air compressors choose diesel compressors over gas air compressors

1.Reliability.  Since a diesel engine runs at a lower rpm (revolutions per minute), it doesn’t wear down as quickly as a gasoline engine.  The cylinder walls of most diesel engines are thicker, and the crankshaft, valves, and pistons are generally sturdier.

2.Lower fuel costs.  Diesel contains at least 10% more energy than gasoline, offsetting the higher cost of diesel.

3.Higher flash points.  That warning that smoking and pouring gas don’t mix has to do with the temperature at which a spark can ignite the fuel.  Gasoline has a flash point of -45 Fahrenheit. 

Diesel’s flashpoint is between 100 and 130 degrees (depending on whether it is #1, #2, or #4).  This makes diesel a safer fuel.

The Disadvantages of Diesel Air Compressors. 

There are several disadvantages to diesel air compressors.  A major one is that diesel engines typically need more maintenance due to their increased complexity.  Another is the search for diesel, although users of diesel vehicles don’t have this problem.  However, this is a moot argument for anyone looking for a small diesel air compressor as they are extremely difficult to find.

Who Uses Diesel Air Compressors 

The most common use of portable diesel air compressor is in the infrastructure construction industry. Commercial-sized diesel compressors can handle 60-pound jackhammers, vertical or horizontal grinders, 1-inch impact wrenches, and OTR tire inflation. 

Compressors of this size come with a rotary screw or reciprocating air ends, and—because they weigh up to 2,000 pounds–can be vehicle- or skid-mounted, or as a tow-behind.

For those who need more than 10-20 c.f. per minute, will use a commercial-sized diesel compressor.  Such units will be used by tire service, some municipal utilities, and mobile mechanics services that need up to 250 c.f. per minute require a heavy-duty compressor.  

Factors to Consider When Choosing an Air Compressor

Two stage compressors provide more power because air is compressed twice between the inlet valve and the tool nozzle.  In a single-stage compressor, the process is as follows:

  • Air is pulled in the cylinder
  • The air is compressed to 120 psi in a single stroke
  • The compressed air is sent to a storage tank where it powers tools designed for single-stage compression

The two-stage process has an important variation that provides additional power—on its way to the storage tank, the compressed air is compressed a second time, to approximately 175 psi.  This more highly pressurized air is cooled and then sent to the storage tank to provide energy for high-powered equipment.

If you are new to compressors, one way to distinguish between a one- and two-staged compressor is by looking at the cylinders.  Two-stage compressors have a shorter piston linked to a longer one by a cooling tube.  

Piston or Rotating Screw

The piston system is what most of us are familiar with—air is introduced into a chamber and the pistons move continuously to compress air.  These are often used by mechanics and in construction.  

Rotary screw compressors rely on two interlocking, rotating screws that drive air into the chamber and further compress the air because they “shrink” the chamber.   They are often used in heavy-duty industrial settings.  

Picking the right size compressor is determined by the tools that will be in use.  

  • Consider all the tools you will run at one time.
  • Add together the CFMs that you plan to use at one time.  
  • To prevent your compressor from overloading, add 25% on top of that.
  • Base your PSI on the tool that requires the highest pressure.

Keep two things in mind.  First, be realistic about the number of tools that will be running at once.  It’s one thing to have five sanders and another to run all five at the same time. 

Second, the more complicated your facility, the more complicated calculations become.  At some point, the back of the envelope calculations won’t be enough and spreadsheets will be required.

Image Credit: https://kaesertalksshop.com

In Conclusion 

Diesel air compressors have several advantages—they last longer, have lower fuel costs, and require less maintenance.  Their portability make them ideal for outside work where access to electric power is limited.  

Contact us at Air Compressors USA so we can help you pick the diesel air compressor perfect for your needs.