A friend asks, “Would you explain to me the difference between a full hybrid (Escape, Fusion) and a plug-in hybrid? I figured you’d certainly be the guy who could delineate these.”
Boy, does he ever show a lot of faith! Here’s how I answered:
Conventional gas-electric hybrids like the Prius, Escape, and Fusion are self-contained, so that all the electric current is created onboard via the motor-generator and the regenerative brakes. That current is stored in the batteries for electric-only or variable-assist propulsion. But you’re really using the gas engine to generate the current.
I had read in the Wall Street Journal that Ford licenses Toyota’s system, but blogger Sam Abuelsamid refuted that contention, saying Ford developed its similar system independently of Toyota, based on a TRW design, and the two manufacturers have a cross-licensing agreement.
Anyway, if you return to the garage in your conventional hybrid after vigorous driving has demanded a lot of assist from the electric drive system, the batteries are going to be nearly depleted and will have to wait till the next outing to be recharged. I first drove the second-generation Prius on an Automobile Magazine All Stars test in Kentucky and Tennessee, and spurring the car up those hills required so much electric-drive assist that the batteries were soon depleted. Then you were left to prod a relatively heavy car (it was then around 2800 pounds; the third generation has surpassed 3000 pounds) with a wheezing 1.5-liter engine.
Toyota promised a plug-in Prius for fleet buyers by 2009, according to another Journal story, “Converted Hybrids Find an Outlet,” from Dec. 30, 2008. But I see nothing about it in the company’s 2010 press kit.
A plug-in would still have the conventional hybrid setup. But different software and perhaps a supplemented array of batteries, as well an electrical charging port, would allow the owner to plug into an outlet to recharge the storage batteries. The software might also be biased in favor of electric drive, so you could start off in the morning under full electric power and drive to work. If it’s not too far and there aren’t too many hills to climb or a too cold ambient temperature or too much draw on the A/C and other auxiliary systems, you could arrive without needing assist from the gas engine. So in effect, it’s an electric vehicle. If the driving continues long enough to deplete the batteries’ charge, then the gas engine would start up.
People like my wife, who lives just eight miles from work, might even be able to drive back home in EV mode and then just plug in for the evening to recharge.
But there must be significant technical issues involved here. That Journal article talks about converting conventional hybrids to plug-ins. Some “tuners” in California were doing the conversion for $7000. You’d never break even in fuel savings, but what’s it worth to reduce your carbon footprint? However, as the story notes, one of these conversions caught fire.
Meanwhile, I’ve also found a clip in my file from Automotive News, 4 Dec 2006: “GM’s plug-in Vue: When…?” I guess the Twelfth of Never.
The Chevy Volt will have a plug-in feature. And as I understand it, the gas engine will never be involved in directly driving the car–not even in a variable-assist situation; it’s just an onboard generating device for fresh current.
An incidental note here: The Volt has won abundant praise for its exterior design, but I find the car unappealingly generic-looking and am especially repulsed by the blacked-out rockers and sills, which are probably meant to give the body an ovalized appearance. It just looks gawky. And the Volt is small. No matter what Washington tells us, Americans like big cars.
This car symbolizes the great hope of Detroit. But if it really comes in at $40,000, as suggested, I don’t think production will require a third shift.