... a solid platform for Natural Gas savings       


Clean Air Power's Legacy technology is a patented Dual-Fuel™ system which enables heavy-duty diesel engines to operate primarily on natural gas. This provides users with diesel engine performance, significant fuel cost savings and low emissions without sacrificing the diesel engine's characteristic efficiency or reliability. 

Combining the Dual-Fuel™ system with an existing Caterpillar engine (1998-2002), gives you Clean Air Power's Legacy. Installations are available for a used truck, re-power or in a new Glider. Gliders are available from Peterbilt, Kenworth, Freightliner and Western Star. 

 C10                                        C12                                         C15

These engines all have met EPA standards and the C15 model is still the highest highest horsepower on-highway natural gas engine ever brought to market. 

The application of Dual-Fuel™ technology does not require any major modifications to the existing engine platform. Clean Air Power's Hawk ECU receives the fuel command from the Caterpillar ADEM engine controller. The HAWK then re-calculates the correct amount of natural gas and diesel (diesel pilot), and the timing of the pilot injection. The natural gas is injected into the intake manifold and compressed with the air in the cylinder and is subsequently ignited by the diesel pilot. 

In 1996, Clean Air Power entered into a license agreement with Caterpillar Inc. The relationship allowed Clean Air Power to develop and market Dual-Fuel™ conversions for their heavy-duty on-highway engines. The system was developed for CAT C15, C12 and C10 engine models. Sales have continued in both the USA and Australia. These engines all meet CARB and EPA standards and the C15 is still the highest horsepower on-highway natural gas engine ever brought to market. 


C15 example

Check for your state's tax incentives on Natural Gas vehicles:

Technical Support
Diagnostic Tool: Key Service Aid 

Helpline: Primary support manager allocated, backup telephone support and the ability to remote log-in to Diagnostic Tool

Ability to provide hands on support


Distributor Information
Please contact us directly for more information on how to become a distributor for your area here


Courses are available for:
- Drivers
- Service Technicians
- Distributor Sales & Marketing Staff

Material covered is aligned to documentation

Customized "Train the Trainer" courses available

Routine Maintenance

Clean Air Power's Legacy Dual-Fuel™ systems require minimal routine maintenance. It is recommended that the natural gas filters are changed every 30,000 miles. Also, to maintain performance, the Clean Air Power natural gas injectors (six), have a recommended change interval of 100,000 miles.

The injectors are externally accessible and can be easily changed in less than an hour with no special tooling. In the event of any unforeseen issues with the Dual-Fuel™ system or limited Natural Gas availability, the engine automatically reverts to diesel fuel operation. This allows drivers to continue to convenient service or fueling points after completion of their route. 

Case Study
Compressed Energy Systems is a natural gas supply business in Eldorado, Illinois. Owner Chris Schimp's  interest in natural gas developed quickly after he recognized the opportunity for heavy-duty vehicles. He originally purchased used C12 Legacy units from a previous Clean Air Power customer and began running those in his own fleet. Subsequently, he leased them to customers along with natural gas fuel. One of his customers, Freedom Waste, is reporting over 80% gas substitution and is in the process of adding additional units to their fleet. 

Today Chris has built four new Peterbilt Gliders. His fleet also includes C15 Legacy systems which are rated at 500 horsepower. 

"The savings are amazing, and the flexibility of the Clean Air Power Dual-Fuel™ system makes these units a no brainer for my customers. I am looking to expand my fleet of lease vehicles to increase our sales of natural gas. This system makes it easy and all parties win!" 

- Chris Schimp, Compressed Energy Systems.