Readers of London's Sunday Times kept telling the auto reporters that the official mileage numbers for the Prius were overstated by about 15 imperial mpg. Intrigued, the Times decided to test things out by running a Prius against a BMW 520d with regenerative braking from London to Geneva, a 460-mile trip. Then they added 100 miles of urban running to give the Prius a chance to recover ground on its proper turf.The verdict: the conventional diesel with Efficient Dynamics beat the full hybrid by 2.2 imperial mpg, or 1.8 US mpg. This means that an executive sedan with all the mod-cons and 500 extra pounds beat the mollusk-shaped sip-tastic wunderkind known as the Prius. And the diesel's COemissions are just 32 g/km higher than the hybrid poster-child, to boot.Admittedly, we find the test a bit unfair -- the Prius is not meant show its muscle at "75-mph into a headwind," and adding 100 miles of urban driving doesn't make up for 460 miles of autoroute. Reverse those driving conditions and then let's see who won. Still, for all of us diesel fans out there, it's a feather we won't mind putting in the cap. Thanks for the tip, George![Source: Sunday Times via Technoride