Class 8 Trucks

The U.S. Department of Energy SuperTruck program is an initiative that aims to increase the fuel efficiency of Class 8 trucks by 50%. The DOE objective is to attain 40 percent of the overall efficiency gains from engine improvements, with 60 percent coming from other sources such as aerodynamics, lighter weight materials and reduced drive train friction.

In Europe, the European Commission – Climate Action & The International Council on Clean Transportation (ICCT) in Brussels are charged with a task similar to the SuperTruck program. It is interesting to note the following allocation of energy losses on a Class 8 vehicle:

Engine                   59%
Tires                      22%
Aerodynamics        16%
Accessories             2%
Axle                         1%

Yet the allocation of fuel economy improvement attributed to new engine design is only estimated at 6%, and that is by capturing exhaust heat to run steam turbines that generate electrical power (see History section date 2011 for BMW car equivalent). This is a long way from the DOE goal of obtaining 40% of the overall efficiency gains from the engine.

The 59% energy loss is actually heat that was a result of combustion in a diesel engine, which is exactly the heat that the ZED engine captures to increase fuel economy. The proposed exhaust turbine therefore is not much more than an afterthought. What Class 8 trucks need is a new engine which can use all of the pressure and all of the heat of combustion. A gasoline or diesel engine cannot do this without catastrophic failure, which means both the United States and European programs are missing the easiest and quickest way to reach their objective – the ZED engine.

Today, external combustion engines globally produce more power than all internal combustion engines combined in all uses. It would seem a logical leap therefore to refine and adapt this dominant design to vehicles, including Class 8 diesels.

The fuel use potential savings may be substantial as Class 8 trucks represent only 4% of all on-road vehicles in the USA and about 6% in Europe, but are responsible for almost 22 percent of all global on-road fuel consumption. The DOE advises that increasing Class 8 fuel economy from about 6.5 miles-per-gallon to 9.75 miles-per-gallon would save $15,000 in annual fuel costs per long-haul truck. It is calculated that a ZED powered vehicle would achieve over 12.4 miles per gallon, a level unachievable by a conventional engine for a fuel savings in excess of $25,000 per annum.

ZED engines are particularly adaptable to trucks due to their high torque curve at low RPM, which resembles that of an electric motor and is greatly superior to a diesel engine, let alone gasoline. The adaption of ZED engines would also preclude the need to consider very expensive hybrid Class 8 trucks.

An added value of the ZED powered Class 8 truck is lowered operating cost with a less refined fuel. A ZED powered APU would also be quiet, run on the same fuel, and greatly exceed the durability of current APUs in compliance with anti-idling laws in both North America and Europe.

Where current APU are powered by small, noisy diesel engines in order to be fueled off of the vehicles main tanks, the ZED APU can also run on diesel, but would be virtually silent in operation. Providing heating, air conditioning, electricity, and being quiet gives a driver the best possible rest environment. With miniscule pollutants as opposed to operating the main tractor engine (or conventional APU), and a calculated average fuel savings of 2.0-2.25 gallons of fuel per hour the ZED APU is expected to be the new industry standard. Where a conventional Class 8 APU has an expected life of 3-4 years, the ZED APU is expected to have a service life of 6-7 years.