An early look at variable engine-driven accessories

For only the second time in our history we have we focused our resources on a technology — or in this case a family of technologies — that are not commercially available.

We released our Confidence Report on Variable Engine-Driven Accessories because manufacturers are working hard on a making improvements in this area and we wanted to make sure you had some basic information. All of the items we studied put a load on the engine but do not help propel the vehicle down the road. Basically they rob the engine of power without helping move the vehicle.

They do, however, provide essential vehicle functions and any gains in efficiency would be achieved through changes in design to minimize the energy needed to provide these essential functions.

The main point of the Confidence Report was to bring these developments to light, to provide a foundational understanding of variable engine-driven accessories and to explore benefits and challenges of the various technologies.

I would be remiss if I did not note that the fuel economy gains that can be achieved with variable engine-driven accessories are modest at best. Still we felt they were worth exploring because upcoming Greenhouse Gas Phase 2 regulations are likely to push at least some of these technology choices from unavailable to optional to standard on new trucks.

Here is a list of the technologies we explored in our most recent report:

• 2 speed/modulating cooling fans
• Variable speed water pumps
• Clutched air compressors
• Smart air dryers
• High efficiency alternators
• Dual displacement power steering pumps
• Electrically drive air conditioning compressors
• Electrically driven accessories

Check out the report and give me a call so we can compare notes on which of these technologies you think are most promising.  I know we will see developments in all these areas because one of the things trucking does best is innovate.