For brisk acceleration or driving with a heavy load, though, more turbo boost would be allowed. At those times, larger amounts of ethanol is injected, virtually raising the octane rating to around 150 to achieve maximum power without knocking or damage to the engine. In the end, Cohn says overall fuel savings would be around 25 percent compared to a larger engine with an equal power level.
When asked what the power potential of a 5.0-liter turbo V-8 with ethanol boost would be, Cohn suggested 500 horsepower with peak torque of 700 pounds-feet. Actual figures, of course, may change following durability and emissions testing.
Ethanol boosting requires separate fuel systems, including two fuel tanks (or a split single tank). Gasoline delivery is made through normal electronic fuel injection in the intake ports, while ethanol direct injection requires a high-pressure (around 10,000 psi) fuel line. The engine block and rotating assembly would have to be strengthened to withstand the higher cylinder pressures.
Cohn estimates that ethanol boosting would add $1,000-$1,500 to the cost of a larger gas engine with comparable power, which is considerably less than the $3,000-$7,000 premium for a diesel engine in a pickup. An ethanol-boosted engine would also be cleaner than a diesel.
“I don’t see any issues with emissions because the three-way catalyst (on gas engines) is so effective,” Cohn said.
The beauty of ethanol boosting, Cohn said, is that an ethanol infrastructure is already in place and growing in the U.S. The ethanol boosting technology increases the effectiveness and appeal of E85, he said. Straight methanol, which is already commonly distributed to auto parts houses, can also be used; it’s even more effective than ethanol. If the second tank runs out of E85 or methanol, then power would be reduced by 50 percent to protect the engine in gas-only mode.
Granted, there is some inconvenience in having to monitor fuel levels in two tanks, but EBS estimates that normal driving routines in a full-size pickup would only require 10 gallons of ethanol for every 5,000 miles of use.
"This really takes the gas engine to the point where it competes with the diesel," Cohn said.
Currently, EBS is developing the technology and Ford is building and testing the prototypes. Officials have said the technology could be production-ready in four to five years, and that the technology could be licensed to other automakers.Check back for more input from engineers about ethanol boosting and other diesel alternatives. We’ll also talk to industry analysts about the future of diesel in consumer pickups.