Vauxhall has been told not to run an advert again claiming its Ampera electric hybrid car can travel up to 360 miles after the Advertising Standards Authority (ASA) ruled it was "misleading".
Three viewers complained about the television advert, which showed the car being briefly plugged into an electricity source and later stated "Ampera, up to 360 mile range" in on-screen text.
The three complainants challenged whether the ad was misleading because it suggested the vehicle was capable of travelling 360 miles using electricity alone.
General Motors UK, which owns Vauxhall, responded that the Ampera was a unique type of car because it could be driven electrically for 360 miles. This included 50 miles on a fully-charged battery and the remaining distance using electricity generated from the petrol in the Ampera's fuel tank.
"[General Motors UK] stated that the claim that the Ampera had a 360-mile range was in fact conservative and significantly understated the range achieved in vehicle tests in order to allow for 'real world' driving styles," the official ASA ruling revealed.
Vauxhall added that it went to great lengths in all its advertising to communicate the unique selling point of the Ampera - the petrol engine which worked as a generator.
Clearcast, which helps vet adverts for TV and had screened the Vauxhall ad before broadcast, said it had worked with a motoring consultant when assessing the claims and had been advised the 360-mile range was accurate.
However, the complaints were upheld and the ASA ruled that the ad must not appear again in its current form. Vauxhall was also told to ensure it clearly explained how the car worked in future advertising.
The ad breached BCAP Code rules 3.1 and 3.2 for misleading advertising and rule 9.8 for environmental claims.