@Jim
When the Karma has 50 miles of all electric range you will likely do less than 10% of your annual miles in the range extended mode using the gas powered generator. The point is that efficiency does not matter so much for the 10%. It is more important to have high efficiency for the 90% of the miles driven.

The Volt uses a complex gear and clutch system that add to costs (possible 3000 USD) and weight (possibly 150 pounds) in order to gain some efficiency, perhaps 8%, when driving in range extended mode. However, the weight gain will decrease the efficiency and performance of the Volt when running in battery only mode so it is still questionable whether the Volt is more efficient for the total annual miles than a Volt without the ability to link the motor directly to the wheels.

One more thing. I suspect the people who say the Volt drivetrain is overly complicated are people who don't fully understand how it actually works.

Here's a challenge to all the Volt haters out there. (this site is loaded with them) I'll make a wager with anyone that when the official EPA numbers come out for the Fisker Karma it will be significantly less efficient than the Volt in both charge sustaining mode AND in pure EV mode. Any takers?

@Jim
I love GM as a company and I am thrilled GM’s management had the courage to do an electric range extended car several years ahead of the competition. After all, the fact is that the Volt by far beats the Prius in terms of efficiency and environmental credentials and it does so without any compromise in quality or comfort. However, we live in an open society and we should be allowed to criticize each other and strive to always improve what we can do. I might add, I am often wrong when I criticize something but in these cases you still benefit from learning by being corrected.

You are right. I did not think about that the Volt’s planetary gear also helps to make the pure battery drive mode more efficient by keeping the electric motor nearer its peak efficiency point. However, we both know that this does not matter nearly as much for electric motors as it does for combustion motors. Moreover, gears are not perfect either. It may not be an entirely fair comparison but the Leaf has an EPA rated consumption of 34kwh per 100 miles whereas the Volt uses 36 kwh per 100 miles in its pure electric mode according to EPA. In other words, the Leaf is more efficient despite being a larger car with space for 5 and a larger trunk than the Volt. Also the Leaf uses a simple single speed gearbox. The Volt can do 0 to 60mph in 9 seconds (with assistance from the ICE motor) and the Leaf can do it in 9.9 seconds so they are almost equally powerful. My point is that Nissan has done a really good job regarding efficiency in comparison with the Volt despite keeping their drivetrain as simple as possible.

EV1 got a point in terms of explaining the complex drivetrain of the Volt as a political outcome in a large organization where different people always fight for resources and the least strong group at present is the people that represent electric motors and power electronics. However, it is sad to observe that he on more than one occasion has made opinionated and baseless accusations about people and countries he does not know much about.

The TV celebrity paparazzi show TMZ was showing pictures of Leonardo DiCaprio standing next to one of the first to be delivered (Silver colored) making jokes about the recycled components including used diapers in the seats.

Speaking of gearbox efficiency, you can't beat the disk motor embedded in wheels, eliminating all gears, the motors also can provide traction control more elegant than cycling the brakes, a prototype Austin mini used 4 160 H.P. motors.