Mitsubishi has said that the current test regime for fuel consumption “does the industry no favours”, after an independent test found that the real world figure for the Outlander PHEV differed by 120% to the official figure.

In response to the Which? findings, Mitsubishi said that the New European Drive Cycle (NEDC) which manufacturers are required to put every new model through and publish the results is “outdated”.

It pointed out that the NEDC test was created in the 1970s and takes no account of current plug-in hybrid technologies.

Lance Bradley, managing director at Mitsubishi, said: “The current test regime for emissions and fuel consumption is outdated and does the industry no favours.”

Most manufacturers, including Mitsubishi Motors, make clear that the figures are for comparison purposes and are not intended to reflect what customers might actually achieve, as this will depend on many factors, including driving style.

The official NEDC figure for the Outlander PHEV is 148mpg. However, with average UK daily commuting distances the vehicle can achieve considerably more than this, according to Mitsubishi.

It said that the 67.3mpg suggested by Which? is good for a large 4x4 SUV like the Outlander.

It also pointed out that it has “always made real life mpg very clear in its advertising and printed material”.