DEARBORN, Mich. -- We will likely have a spirited debate over plug-in hybrid philosophy after all.

Ford Motor Co. will release its first plug-in hybrid in 2012, two years after rival General Motors releases the Volt. Ford executives, though, argue that their company should be able to limbo under the anticipated $40,000 price of the Volt as well as potentially come out with a wider range of plug-ins.

The difference comes down to architecture. The Volt is a series hybrid, meaning that the car is powered predominantly by electricity. The gas engine largely exists to recharge the battery. Ford's plug-in will be a power split hybrid with the gas engine and electric motor working in tandem to propel the car.

Power split hybrids generally speaking tend to get lower gas mileage than series hybrids, according to Sherif Marakby, chief engineer for global hybrid core engineering, during a briefing at company offices. But they can also be less expensive to make. Power split hybrids can get by with smaller batteries, one of the most expensive single components in plug-ins and all electrics, because the gas engine directly participates in getting you down the road. Potentially, a battery in a power split hybrid can be up to 25 percent smaller than one in a series hybrid, he added.

"You don't have to size the battery for the worst case scenario," he said. "The battery will be lower in cost."

"It is a better value," he added later.

How all this plays out in the market will be one of the more interesting dramas in electric cars. The Volt will be able to go 40 miles before the battery needs recharging. As a result, consumers will mostly drive on electricity pulled from a wall socket, which in turn could give the Volt a three digit miles per gallon rating (GM has publicly said the car gets 230 miles per gallon). Consumers are amped to a fever pitch: an informal, no-deposit waiting list sponsored by the blog GM-Volt has over 50,000 names. The company hasn't seen this much excitemenbt over its cars since muscle cars ruled the earth. GM has also put the weight of its engineering behind the Volt: the technological decisions and design trade-offs have been intensely scrutinized.

A power split hybrid might only go 20 to 30 miles on electricity alone and the stated mileage as a result will be a lower. Still, the mileage could still be high enough to appeal to consumers attracted to the lower price if there is a sizeable delta. The Volt is expected to cost around $40,000.  (Ford will also come out with its first electric cars next year, but target them initially at fleet car buyers.). Then again, if the Volt is an early hit, Ford will come into the segment as a late bloomer.

How far will Ford's plug-in go on electric power? Marakby wouldn't say, but added "it is not necessarily 40 miles. We will develop for the appropriate range."

If consumers flock to the cars, the company could even make a range of plug-ins with different sizes of batteries. Arguably, GM may have a tough time going below the 40 mile mark because it represents the average number of miles Americans drive a day. Twenty Ford plug-ins are currently being driven in pilots with, among others, Southern California Edison. 

Most other manufacturers are expected to adopt a power split architecture or a close variant. GM in the end could be the only major series hybrid maker. Marakby further added that Ford could have made a series hybrid, but decided to go with the power split architecture.

Mileage stickers on plug-ins ultimately include four figures: highway and city mileage estimates for all-electric driving and another for blended gas-electric driving.

Power splits could, maybe, also leverage technology and components from conventional hybrids. The two architectures are similar. Ford will further try to wring out economies of scale by designing cars around standard platform. The Global C platform, the basis of the recently unfurled Fiesta, will be used as the foundation for seven different cars, including gas, electric, plug-in hybrid, hybrid and diesel cars. These different cars can share an extensive number of components, according to Gunnar Herrmann, the Global C Car Vehicle Line Director.

"You want to do it on a large scale," Marakby said. "We want to make sure that the technology is real. The durability, the testing have to be done right."

GM, though, also has plans to leverage components across platforms and if the Volt goes well, it will come out with variants.

It should be an interesting debate.

Tags: detroit, electric cars, ford, gm, marakby, plug in hybrids, transporation, volt