A highly economical version of the Up city car, which will return at least 95mpg, is headed our way as Volkswagen is now putting in the final touches. This model is likely to be named the Up blue-e-motion and it will be powered by a production version of the powertrain from the XL1 Concept, according to company sources.
The Up’s twin-cylinder, 800cc turbodiesel engine is expected to develop only 47bhp, but it will have the assistance of a 26bhp electric motor.
This engine is actually based on the current model’s four-cylinder, 1.6-litre VW Group diesel engine. The engine’s block is made from aluminum and the bores are plasma coated. It also features a sophisticated balancer shaft set-up to smooth out its unbalanced two-cylinder layout.
The engine and electric motor will be mated to a seven-speed dual-clutch gearbox, says Autocar. But unlike the XL1, however, the Up blue-e-motion isn’t capable of running solely on battery power.
This is because the car’s battery pack is only big enough to power the electric motor during standing starts or for brief periods of hard acceleration
. To help recharge the battery, energy will be reclaimed during braking. It’s likely that the Up will have the XL1’s new ‘pulse starting’ feature, which will make the car’s stop-start mode much more seamless.
In pulse starting, the electric motor spins the idle engine up to the required speed for its restart, making it nearly undetectable by the driver. When powered purely by this hybrid diesel engine, the XL1 returns 141mpg on the EU test cycle.
But because the Up will be at least 300kg heavier than the carbonfibre-bodied XL1 and will have more aerodynamic drag (due to its larger cabin and much greater frontal area), fuel economy will be reduced by about a third when compared with the concept.