A German driver has successfully sued Daimler for overestimating the fuel efficiency of his Mercedes E-Class.

The driver bought a brand new top of the range E-Class in 2005, which the manufacturer claimed would achieve a fuel consumption of 10.2 litres per 100 kilometres in the city and 7.6 litres per 100 kilometres out of town. But the bad news for the car owner was that the actual consumption was around 15% higher.

The total amount of damages has yet to be decided but the district court in Stuttgart has agreed damages of €436 in respect of the 53,000 kilometres driven so far and the carmaker will have to give back €2,500 as a reduction of the €62,000 purchase price. In addition Daimler will have to pay compensation for future fuel use and court costs.

An interesting point about this case is that Daimler argued that fuel consumption is not an absolute - each driver has its own driving style, and that affects consumption. And what's more, the weather conditions, road surface and air-conditioning could all affect actual consumption.

We already knew that, but it's strange to see a carmaker using that as a defence when the car lobby has been fighting hard to get the "integrated approach" adopted, arguing that we all have a role to play in reducing CO2 emissions and crucially, trying to get part of the EU target offloaded onto the motorist.

But when they're asked to justify their fuel consumption figures, they blame the driver. Well, yes, it's true, that eco-driving isn't as easy as many people think and fuel consumption does vary depending on how the car is driven, but you'd think Daimler would know that and be able to adjust their figures to take human nature into account.

But though this case may be a breakthrough in getting carmakers to be a bit more realistic about their fuel consumption, according to lawyer Silvia Schattenkirchner from ADAC the German car drivers association, it’s not setting a precedent. Car owners who suspect their vehicles aren't matching up to the figures in the glossy brochures will have to have their car tested before a claim can be made.