Diesel Hybrid
 

Just a thought from someone that it fairly new to eco modding......why is there no diesel hybrid. These together seems like the way to go. Railroads locomotives have been using this basic technology for close to 80 or 90 years. Match up a TDI engine in a prius body....hhuumm.

Cost ?
A diesel engine is more expensive with all assorted extra gear (soot filter, common rail injection). A hybrid is also more expensive.
Both together would be very expensive.

Peugeot is working on one though :
Frankfurt Preview: Peugeot 308 Hybrid HDi gets 69 mpg with only 90 g/km of CO2 — Autoblog Green

VW say they aren't going to make one.

Actually, there is one...
World's only Diesel Honda Insight

Brilliant stuff !

If there never was a Mod of the Year for 2009, this amazing transplant should be getting it !

That tapped Peugeot have been 'working' on one for a hell of a long time, I remember reading press stuff in 2007. I wonder if they are just realising that the benefits of Hybrid + Diesel is not worth the extra effort given how much they seem to be able to stretch the MPG vs BHP ratio for Diesels.

After all they now get more BHP from a 1.6 now than they used to get from a 1.9 in the late 90s and with more MPG.

e.g. Peugeot XUDT 1998 would be ~92bhp and 45 mpg, and a 307 1.6 HDI would be 90bhp (110 option) with 55+ - more for an ecomodder driver.

Until the TSI-style small capacity petrol turbos recently I haven't seen the same development for them. Loads more power and the same MPG but not loads more MPG with the same power.

What about replacing the turbo on a TDi with an electric motor? The electric motor could provide the extra power normally supplied by the turbo during acceleration, and the lack of engine braking would really suit regen braking. The cost of the electrics would at least partially be offset by the elimination of the turbo.

Are you thinking of a supercharger ?
Correct me if I'm wrong, but a turbo runs off the exhaust.

No, using an actual hybrid drive to provide electric power during acceleration, rather than using a turbo to add fuel/air.

Turbos are about the cheapest thing out there.

So are electric motors.