Suski is heading up a TMC task force that's looking into the viability of future “power plants” for trucks, not calling them engines, because some do not function like traditional engine technology.
A low heat rejection engine is being investigated heavily by the Dept. of Transportation. Called the LE-55, it does not have a cooling system, relying instead on its lubrication system to reduce engine heat.
By using advanced fuel injection timing – 30,000 to 40,000 psi versus the typical 25,000 for a standard diesel engine – turbo-compounding and high temperature synthetic lubrication oils, the engine could actually operate at 55% thermal efficiency as well as cut way back on exhaust emissions. That would make it cleaner and more fuel-efficient than today’s diesels.
Fuel cells and hybrid electric systems have more limited potential, according to initial research displayed by Suski. Fuel cell technology uses hydrogen gas to provide electric power, with only water and oxygen as byproducts. However, while fuel cells are being used to power buses, range limitations make them less than ideal for commercial trucks at this stage. Fuel cells are being experimented with as an auxiliary power source to reduce engine idling in trucks.
Hybrid electric power plants could fit the short- and medium-haul trucks, said Suski, Since studies have shown that diesel fuel amounts to 50% of a trucking firm’s operating costs, using electricity in short-range applications may make economic sense.
Electricity on average costs $0.06 a mile, versus diesel’s $0.17. However, hybrid electric power plants cost a minimum of 15% more than traditional diesel technology and have very short range. Also, electricity price spikes in recent months have cast doubt on whether electricity will remain inexpensive in the future.
Suski added that his group has selected three ‘teams’ to study all available material on each power plant concept and will present position papers in the near future, listing their potential advantages and drawbacks in commercial truck applications.