A Better FFV?

Single nozzle, dual fuel injection could work in heavy-duty trucks, too
By Holly Jessen | September 12, 2011

What if there were a flex-fuel engine on the market that was more efficient, and provided more power than today’s flex-fuel vehicles (FFVs) and was affordable? Better still, what if that engine could also be used for heavy-duty vehicles that now use diesel engines?

That’s a future that Cambridge, Mass.-based Ethanol Boosting Systems LLC, an MIT spinoff, has been working toward. In early August, the company took a step closer when the U.S. Patent and Trademark Office issued a patent for a single nozzle, direct injection system for rapidly variable gasoline/anti-knock agent mixtures. It utilizes a second tank, which could contain ethanol or methanol, for direct injection at high power levels. “It could be a game changer for engines because it’s the most cost-effective way to get high-efficiency engines,” says Daniel Cohn, CEO and cofounder of Ethanol Boosting Systems. “And it’s good for ethanol because it opens up the possibility for flex-fuel heavy duty truck engines for ethanol—that’s a big potential win for ethanol—and it makes flex-fuel light duty car engines more attractive.”

U.S. DOE funded testing in collaboration with Ford, confirming what Ethanol Boosting Systems’ computer models showed. “This technology opens up the possibility for high efficiency, high torque, flexible-fuel engines for trucks. These engines have a lot of advantages over diesel—they are cheaper, they’re cleaner and they provide more power.”
While critics blame ethanol for a variety of engine-related ills, Cohn points to shortcomings of gasoline. Ethanol is a superior fuel, he says, because it’s higher octane than gasoline and can be operated at a higher compression ratio with more turbo charging. The problem with conventional FFVs is that it’s not possible to achieve maximum efficiency and torque when the vehicle is run on gasoline. The performance of the engine has to be degraded, otherwise, when it was running on gasoline the engine would have issues with knock. “What’s really nice about our engine is it’s a no compromise FFV, that is, you design it for the maximum performance of ethanol,” he tells EPM, adding that while it’s true ethanol has less energy per gallon than gasoline, this engine compensates with higher efficiency.

Another piece of good news is that, with the FFV configuration, there’s no need for special handling for the second tank. Every time the driver fills up with a higher ethanol blend, the fuel is directed into the second, smaller tank. “So the second tank is always poised to be used,” he says, as long as the driver fills up with E85 often. 

—Holly Jessen