Why Not Run Hybrid Cars On E85 Or Biodiesel?

Dear EarthTalk: What would be the feasibility of having hybrid cars run on E85 or biodiesel? Wouldn’t this solve multiple problems?

—Bob Pendergrass, Broken Arrow, OK

Environmental advocates would love to see carmakers mass-produce a biofuel-electric hybrid. From a technology standpoint, it’s a no-brainer: Major automakers already turn out vehicles that can run on E85, a blend of 85 percent ethanol, derived from corn and other crops, and 15 percent standard gasoline. Ford’s light duty F-series pickups are examples of such “flex fuel” vehicles. And gasoline-electric hybrids, like Toyota’s Prius, are all the rage and beginning to be ubiquitous on the roads.

biodiesel hybrid
Credit: Skitterphoto, Pexels.

Cost, however, is an issue, says Jim Kliesch of the website greenercars.org. Traditional cars and trucks powered by diesel, biodiesel or ethanol cost more to manufacture than equivalent gasoline-power vehicles. And gas-electric hybrids also cost more than conventional cars, largely because their market share is still small and economies of scale have not yet kicked in. Thus combining two costly technologies in a biofuel-electric hybrid would constitute “a double-whammy,” says Kliesch, “limiting the vehicles to a very small slice of the market.”

Nonetheless, Ford last year unveiled a prototype of its popular Escape Hybrid SUV that runs on E85. Like the gas-electric hybrids now on the road, the E85-electric hybrid Escape maximizes fuel economy by alternating between its internal combustion and electric engines. And it never needs to be plugged in because its high-capacity batteries store electricity generated from braking and other processes in-car.

Ford estimates that if only five percent of U.S. vehicles were powered by ethanol-electric hybrids oil imports could be reduced by 140 million barrels a year. Such vehicles would also produce about 25 percent less carbon dioxide (CO2)—a chief contributor to global warming—than traditional cars and trucks. What’s holding up mass production, says Ford, is a lack of E85 fueling outlets—only 1,200 exist across the U.S.

Not to be outdone, General Motors (GM) has its own ethanol-electric hybrid in the works via its Sweden-based Saab subsidiary, which unveiled a prototype in 2006. The company claims that, whereas Toyota’s gas-electric Prius emits 104 grams of CO2 per kilometer, their E85-based hybrid should emit just 15-20 grams. Industry insiders don’t expect to see such a vehicle available to the public until 2010 or later.

With regard to diesel-electric hybrids, though diesel spews particulates and other nasty ground level pollutants into the environment, it contributes significantly less CO2 to the atmosphere than gasoline. And biodiesel, a form of the fuel derived from plants, is both carbon-neutral (burning it contributes no additional carbon to the atmospheric balance of the pollutant) and cleaner burning in regard to particulates. It can be used interchangeably with regular diesel in most diesel engines. Thus combining biodiesel with an electric motor in a hybrid car or truck would yield one of the cleanest burning engines on the road.

GM and Chrysler have already collaborated on developing a diesel-hybrid platform that combines dual electric motors with a diesel engine to offer unparalleled fuel efficiency. But whether such vehicles ever see the showroom floor—and whether consumers will be able to even afford them—is anybody’s guess.

CONTACTS: GreenerCars.org; E85vehicles.com