Volkswagen has halted development of a turbocharged 1.5-litre four-cylinder originally scheduled for 2018 in the upcoming sixth-generation Polo, in favour of a new petrol-electric mild hybrid driveline.
The new aluminium block high-pressure common rail unit was planned to form part of a new small engine offensive by Volkswagen, in combination with the recently unveiled turbocharged 1.5-litre four-cylinder direct injection petrol unit launched in the facelifted seventh-generation Golf.
However, high engineering costs coupled with ever tougher CO2 and NOx emission standards, and waning demand for diesel engines in Europe’s B-segment, in the wake of the dieselgate scandal, has led to Volkswagen abandoning its original small diesel engine strategy and switching its engineering focus to small capacity petrol-electric hybrid drivelines instead, according to the German car maker’s head of research and development, Frank Welsch.
Speaking at the launch of the new Golf in Spain last week, Welsch singled out the high cost of developing an effective after treatment system for a successor to today’s turbocharged 1.6-litre four-cylinder diesel – the EA827, as it is known internally – as a key component in the decision for the switch in driveline strategy.
“The added cost is anything from six to eight hundred Euros in material costs just for the after-treatment system,” he says, adding, “The after-treatment system is as expensive as the engine itself. To add a diesel in the Polo, it is 25 percent of the car itself.”
Welsch wouldn’t put a definitive timeframe on when Volkswagen would cease to offer a diesel engine in the Polo and its future derivatives, including a new entry-level SUV previewed by the T-Cross Breeze concept, although he indicates the days of the existing turbocharged 1.6-litre four-cylinder engine are numbered. “Three to four years, maybe five,” said the 52-year-old German when asked how long the EA827 would be available.