Fisker has just released pictures of the road-going version of its Karma. If you’re struggling to see how this car is different from the ones they made earlier, don’t worry; it’s not you.

karma1 It’s because the Karma hasn’t changed much. The exterior design of this car has been effectively ‘locked in’ for months now.

Most of this car has been ‘locked in’ for a while, in fact, with the exception of its petrol engine. Announced only last month was a deal done with General Motors to use GM’s 260bhp 2.0-litre turbo petrol four-pot as a generator for the plug-in hybrid powertrain.

One of the few changes to the bodywork comes at the front of the Karma. In light of that new engine; the grille has grown a little larger to provide better engine cooling.

What I don’t understand is why General Motors would get into bed with the only firm likely to beat it to market with a petrol-powered ‘range-extended electric vehicle’ (plug-in or series hybrid to you and me)?

Surely the Volt is an important enough vehicle for the General to protect from any competitor, and given the best chance possible when it goes on sale in 2010. By supplying a more powerful motor for the 2009 Fisker than the Volt will run, plus expertise in helping to make it work in a series hybrid powertrain, isn’t GM contributing to the theft of its own thunder?

Maybe GM would argue that this is the last of its worries right now. Maybe it would say that the Volt and the Karma will be very difficult cars, the Volt a $35,000 volume car, the Karma a much lower-volume $80,000 sports saloon. “If GM didn’t sell Fisker the engines,” they’d say, “someone else would”.

But the Volt is GM’s future. And my point is this: how much put PR value do you put on the chance to be able to say you’re the first at something? More than you get from flogging a couple of thousand customer engines a year? I’d say so.

And who knows, if Henrik Fisker had to look a little harder and longer for the engines for his four-door Karma, maybe he would have missed his autumn ’09 on-sale date. And maybe then the Volt’s 2010 launch party – assuming GM survives to throw it – would have been all the merrier as a result.