AutoExpress UK takes on the challenge to compare two of the most green compact premium cars: BMW 320d EfficientDynamics and Audi A4 TDIe.
Available only to European customers, the 320d ED is powered by a turbocharged 2.0-liter four cylinder diesel engine with common rail direct fuel injection and variable intake geometry.
To increase the fuel economy of the BMW 320d to a maximum, the EfficientDynamics Edition saw a reduction in power from 184 hp (135 kW) to 163 hp (120 kW). Furthermore a centrifugal pendulum absorber was integrated in the dual-mass flywheel of the engine.
Innovative Energy Saver tires with reduced rolling resistance, along with other fuel savings features, allow the BMW 320d ED to be driven 1,375 km (855 miles) with the 57 liter (15 gallon) fuel tank. The fuel economy is 4.1 l/100 km (57 mpg).
The Audi A4 TDIe is powered by a version of the company’s familiar 2.0-litre turbodiesel, tuned to 134bhp. The A4 2.0 TDIe improves upon the 40 to 48 mpg achieved by the rest of the A4 2.0 TDI lineup to earn a combined 51 mpg. Key to the efficiency improvement is a start-stop system that cuts engine power at idle when neutral is selected and the clutch is released. The system restarts the engine in two-tenths of a second when the clutch is depressed.
Here an excerpt from their review:
In the closely fought company car arena, only two vital statistics really matter: fuel economy and CO2 emissions. Judged on these criteria alone, the ultra-efficient BMW takes a comfortable victory.
Yet there’s more to the 320d ED’s win than its superior efficiency. For instance, its boasts the kind of driver engagement that can turn an everyday journey into a great drive, while the larger cabin and boot make it a surprisingly family friendly choice. It’s also backed by a great-value service pack and much stronger residual predictions.
That’s not to say the Audi isn’t without merit. It’s a comfortable and capable choice, and our SE-spec test model also represents decent value for money – not always what you expect from Audi. But it costs more as a company car, has a heavier thirst for fuel and is nowhere near as engaging to drive.
This result is further proof of the 3 Series’ sheer dominance over the market, and BMW’s expertise in efficiency is clear across its model line-up. None of the car’s rivals has yet managed to come close to offering the same combination of low emissions and lively on-road performance. It’s not often that the cheapest car to own in a range is also the best to drive, and few cars appeal to heart and head quite as easily as the new 320d ED.