why not hybridize a hi-tech diesel car?Why won’t bring hi-end diesels here?
I’ve always said (on the basis of mechanical engineering lab work in college) that anyone who claims to be going all out for fuel economy - and what else is a hybrid supposed to be? - isn’t really trying if they’re using a spark-ignition engine instead of a diesel.But then, what actually is the point of going full-bore for fuel economy when we have shale oil and gas? Speaking of natural gas, how much better is an electric car than a CNG-fueled car for anything? Incidentally, it’s possible to use (a lean mixture of) NG in a diesel engine, using the fuel oil injectors only to initiate combustion. Highly efficient.The historic limitation of the diesel, besides initial cost, weight, and the fuel-oil smell, has been flexibility - the power curve vs RPM is pretty much linear up to the (low, due to high piston mass) RPM red line. Which tends to require a lot of gear shifting. But a hybrid shouldn’t have the same problem with that . . .
My conclusion is that they don’t use diesels in hybrid designs because of weight and initial cost. The high gas mileage you already get from the hybrid feature reduces the payoff in fuel economy of changing to diesel prime mover, and the high cost and weight of the hybrid makes the high cost and weight of the diesel that much more painful. I guess putting a diesel in a hybrid is “a bridge too far . . ."
I suspect most buyers want the highest efficiency in $$$/mile, not miles per gallon. That makes the diesel hybrid a tough sell when including the purchase price.