Mercedes 300 DE - the last diesel hybrid?

[cRiPpLe_rOoStEr]

Originally Posted by Michaelflat1

Keeping a diesel engine in it's sweetspot whilst driving demands change (using electric motor assist) would have incredible fuel economy.

Maybe for engine operation at a fixed speed, a microturbine could be OK. Well, even though nowadays axial compressors are more common on aircraft engines nowadays, centrifugal compressors might remain suitable for a range extender in an EV. Or even if it would eventually provide power directly to the wheels in a hybrid. And since a turboshaft can be made quite fuel-agnostic, I guess it could please both those who prefer spark ignition and those who would like a Diesel hybrid.

[GreenTDI]

Originally Posted by Michaelflat1

However small 4 cylinder diesel engines are quite tractory in nature and you'd definitely know when they turn on.

You mean 2 and 3 cylinder diesel engines? Those 4 cylinders are quite civilized nowadays. Even the newest 1.2 3 cylinder CR TDI is quite refined comparing the old PD ones. At constant speed between 1000 and 1900 rpm the engine sound does not exceed other driving sounds.

[cRiPpLe_rOoStEr]

I'd be actually willing to try some 3-cyl Perkins or Yanmar TNV, even though those are clearly too agricultural for the average Joe's taste.