The latest diesel-powered cars offered in Europe come close to - and in a lot of cases beat - hybrid-electric cars like Toyota's Prius in the mileage stakes, so imagine what would happen if you combined the best of both technologies. France's Peugeot hopes to do just that and by becoming the first carmaker to launch a diesel-electric hybrid by the end of the decade.
The recently launched midsize Peugeot 308 hatch will be the first vehicle fitted with the new powertrain, but it's likely other models will soon follow suit if it proves to be successful.
The Peugeot diesel hybrid should average better than 70mpg (58.3mpg US), which would mean its emissions levels would be lower than most other cars except for pure electric vehicles. By comparison, the Prius rates 65.7mpg (54.7mpg US). However, most motoring mags have found its real-world fuel economy ratings to be much lower.
The only factor holding back the release of the hybrid 308 is the high cost of the batteries and electric motor, but engineers are working hard to make the technology more affordable.