Daimler and BMW are feuding over just whose test fleet of small electric cars is closest to serial production in an attempt to ditch their image of thirsty, high-performance luxury cars.
Long reliant on hulking V8s like the BMW X6 sports utility vehicle or sporty coupes such as the Mercedes-Benz SLS AMG gullwing, both are now quick to emphasise their efforts to develop zero emission vehicles.
In July, BMW even went so far as to sell its exit from Formula One following a dismal season as part of a "strategic realignment" to channel resources for the development of new sustainable powertrain technologies.
"We have the largest fleet of e-cars out there on the street -- with customers that use them every day," said Klaus Draeger, BMW's head of research and development, during the Detroit auto show.
Meanwhile, Mercedes R&D chief Thomas Weber boasted that "we are already in serial production while others are still tinkering around on showcars".
In fact, no carmaker has sold anything but a miniscule number of electric cars. Full scale industrial production of zero emission cars is largely expected around 2012 and market shares of over 5 percent are unlikely within this decade.
BMW for the moment is pilot testing only some 600 Mini brand cars on the roads worldwide that are powered entirely by battery, while a hundred Smart EDs made by Daimler with the help of its partner Tesla have avoided the congestion charge in London since 2007.
A small series of 1,000 electric Smarts would be built starting in November and delivered to customers at the earliest by the end of this year, before the vehicles eventually roll off assembly lines at Daimler's Hambach plant in 2012 as a permanent addition to the brand's model line.
Volkswagen and its luxury brand Audi admittedly cannot even claim that. Audi's E-Tron sports car just debuted in September as a concept that might come in 2012 and VW plans to make just 20 Golf twinDRIVE plug-in hybrids this year.
Audi says fewer than 1,500 electric vehicles are currently registered in Germany, corresponding to only 0.035 percent of all registered vehicles.
"Some manufacturers are already releasing their e-cars on customers. We are only using test fleets," VW brand R&D chief Ulrich Hackenberg, who called the technology a "hype".
The engineer believes his company is doing a favour to VW buyers by sparing them the possibility of getting behind the seat of a car that may still have plenty of bugs in the system.
"The worst thing would be if the technology doesn't work and it results in damage. That is something that we do not want to have associated with our brand," Hackenberg explained.
VW prefers to offer a range of "Blue Motion" vehicles that reduce emissions by making relatively small changes to a car's aerodynamics, boosting the efficiency within the combustion chamber and attaching turbochargers to the engine.
Horst Schneider and Niels Fehre, analysts at HSBC, sympathise with VW's stance despite the inherent risks of losing a perceived technological edge to carmakers including Renault.
The French rival has committed itself to selling four separate zero-emission electric cars by 2012, all of which were shown off at the Frankfurt auto show like the E-Tron.
"Unreliable or unsafe technology would damage the image of electric vehicles and of their manufacturers," they wrote in a 200 page study on electric cars.
Popular in Europe after the development of modern common rail fuel injection systems, for example, diesels have suffered a niche existence after the technology became associated with being dirty, smelly and noisy when General Motors rolled out an infamous range of sooty vehicles in the 70s following the oil crisis.
"Companies like Renault could end up in even deeper trouble. We can understand the wait-and-see stance of the mass-market leader, Volkswagen," the HSBC analysts said.
(Writing by Christiaan Hetzner; Editing by Jon Loades-Carter)