There is a diesel hybrid in the works but batteries aren’t part of the plan. Instead it uses hydraulics to compress nitrogen and uses that for the initial acceleration from stop to about 20mph. It’s a great design for urban delivery type vehicles, buses etc. Ford is hopefully going to show an F-150 at the Detroit auto show in Jan with a production model for the 2009 model year although I think it may be with a gas powered engine. UPS has been testing the concept in their delivery vans.
Yes, I’ve seen a write-up on that hybrid design — hydraulic accumulators. A clever design.
My only reservation is this: every hydraulic system I’ve been around leaks. Every. Single. One.
I’m sure that a hydraulic system that doesn’t leak can be made. I’m not so sure it can be made by Detroit’s manufacturers.