The advert said the hybrid-engined car emitted up to one tonne less CO2 per year than an equivalent diesel vehicle, based on 12,500 miles per year for private cars.
The ASA ruled the Prius could offer reduced emissions compared with non-hybrids, but Toyota’s annual mileage figure, based on US averages, did not reflect British usage.
Based on a UK average of 8,500 miles, said the ASA, Prius would not reduce emissions as claimed. Data provided by Toyota compared its emissions against only Mk1 Prius and a Toyota Allion, sold in Japan only.
The ASA added: “We noted Toyota had qualified the claim by stating ‘up to one tonne less CO2 per year’ and that the Prius emitted significantly less CO2 than some other cars with greater engine capacity. But we did not consider their evidence demonstrated that it emitted one tonne less than equivalent vehicles with diesel engines or that it took into account the average annual mileage of UK private cars.”
Scott Brownlee, Toyota GB spokesman, told AM: “The decision was that while the advert was not wrong, the mileage claims are.
“We disagree. It’s generally accepted that 12,500 miles is average for a new car.”