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It says it gets 100 mpg..... Does that really take into consideration the extra energy taken through the plug? That raises interesting questions about how EPA ratings will be done on these vehicles. They will get wonderful fuel efficiency, but there will have to be new ratings created to measure how energy efficient they are (fully electric H2 vs fully electric Prius). I'm not saying it is a bad thing, especially since electric energy from the grid is much cleaner than petroleum energy, just that it will create a new way of thinking.
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Current hybrids already get to "cheat" at the EPA test by starting with a full pack, and ending the test with a less than full pack. As far as I don't know, the EPA doesn't run multiple trials to account for this effect. Wtih several kilowatts of charged power, the EPA test would be effectively worthless, as it would be only accurate for a trip starting with a full charge that is the exact length of the EPA test, no more, no less.
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It says it gets 100 mpg..... Does that really take into consideration the extra energy taken through the plug?
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It couldn't possibly. I'm sure that the extra power does actaully improve the fuel efficiency of the gasoline engine, even beyond the "free" power, by enabling it to run in a more efficient RPM range and shutting it down more, but nowhere near a 2:1 swing. The 100mpg really should be 100miles per gallon and some kilowatt hours.
To be useful, the EPA data the way it's currently done would need to show results for drive distances of at least three varying lengths, in both city and highway, and assuming a full pack vs assuming an empty pack. That right there is 12 tests. Perhaps those could be averaged to produce a City/Highway value for simple comparative purposes, but even that is pretty sketchy.
At that point, I say it's easier to refer to efficiency in cost to drive. Say you use 1 gallon and 10kWH to to drive 100 miles, at $3 a galllon and $0.10kWh. That would be $4/100mi or $0.04 a mile, as compared to maybe 6 to 8 cents a mile for the standard hybrid. Anywhere from 25-50% savings. Emissions savings should far exceed that, due to more efficient usage of your ICE for less time, and contribution from cleaner grid-derived power.
Also, with the way plug-in hybrids work, for short trips, where the motor can be recharged in between, You woudl use almost no gas. More importantly, by using wall-charged power, you'll spend 4 times less money for very short trips, and contribute very minimal pollution compared to running a cold gasoline engine--even a hybrid engine.
On longer trips, that extra power could be used to make the gasoline engine run more efficiently as well, by using extremely aggressive assist to keep it in its peak efficient powerband, and shutting off the engine more than would be possible otherwise (as there woulnd't be a need for the engine to run to directly replenish the batteries -- a very inefficient process) this way, the electric power could make a significant difference of the entire duration of a long trip as well.
Finally, the extra battery pack should allow the car to do much better in the mountains by providing extra capacity for regenerative braking.
Extra cost to add plug-in ability to a hybrid makes more sense from an economic payback perspective than even adding a hybrid system to a normal gasoline system does at this point.
New player in the plugin hybrid game: $5k for 25 miles
Re: New player in the plugin hybrid game: $5k for 25 miles
