Last week at the Geneva auto show, Mercedes-Benz said it would be considering three-cylinder engines for future compact hybrid vehicles.
According to a brief write-up by Car and Driver, M-B’s powertrain chief Bernhard Heil said the compromise is being looked at despite needs for balancing shafts and other countermeasures to offset inherent noise, vibration, and harshness.
Heil has been variously reported as saying the three cylinders are on the table for front-wheel drive applications, but already ruled out for rear-wheel drive non hybrids.
The aspect that does look favorable is that space and packaging for transversely mounted three-bangers could make it all work.
Obviously also, this is all about saving fuel from smaller displacement engines, a push that is ultimately driven by regulations, not because the upscale automaker has taken a sudden shining to the smallest engines it can get away with.
In a separate article, Heil told Autocar it has already ruled three cylinder engines for rear-wheel drive diesel and gas sedans for the same compromises mentioned above. Balancer shafts add weight and costs, he said.
This Heil said, even though BMW is specifying a three-cylinder for its six-figure i8 flagship plug-in hybrid.
Heil said Mercedes-Benz will probably develop a second family of smaller-capacity diesels with a lower displacement than today’s 2.1-liter OM651 engine. Reportedly 1.9- or 2.0-liter units are possible, though he did not specify a displacement.
One thing is certain, the OEMs are beating the bushes, looking for solutions among the non-electric technology bin.