Downsizing over at Volkswagen

The age of shrinking engines, or downsizing, is over. At least, it is over at the Volkswagen Group.

While Volkswagen has long used three-cylinder motors in its small cars, it has now declared that it will no longer shrink its engines for theoretical NEDC fuel-economy benefits.

“We stopped this at Volkswagen,” the German car-maker’s development head, Dr Frank Welsch, insisted.

“What we have reached now this is fine. There is not heavy downsizing anymore. Some are calling it rightsizing, but that’s not really right, either.

“We will not go lower than 1.0-litres in a three-cylinder or below 1.5 in a four.
The Polo will go to a small four-cylinder engine.”

The benefits of smaller engines in laboratory testing were often found to be wishful thinking in the real world, especially amongst more enthusiastic drivers.

The real-world emissions tests in the EQUA initiative from Emissions Analytics showed the differences between NEDC and real-world tests were particularly large in downsized engines.

The 10 models with the highest percentage difference in the EQUA test all used “downsized” engines, including the Fiat and Alfa Romeo Twin Air 0.9-litre two-cylinder engine, the MINI One 1.5-litre three-cylinder engine and the smart range of 0.6-litre three-cylinder engines.

“Downsizing worked for us but maybe in some cases the approach was too strong,” Dr Welsch admitted.

“The extreme of it was too much. Remember what we tried in three-cylinder diesel? It turned out not be that positive.

“The 1.4-litre three did not work out in the end. People expected too much. We moved back to 1.6- and 2.0-litre engines with diesel.”