Sorry about resurrecting an old thread, but it still appears on the Most Popular Topics list on the EcoModding Central forum
I'd like to highlight my Mercedes sports car diesel conversion.
As has been pointed out at various places in the thread, the early MB diesels weren't terribly efficient, especially when mated to an automatic. Even with those limitations, I've been getting consistently over 30mpg over the past (almost) 60k miles. The car is extremely fun to drive, very reliable and I'd take it virtually anywhere.
If the car were to have the later model 606 engine vs the 617 and a 5 speed manual, it would very likely show 40mpg consistently. While the 606 conversion has been done, the amount of work, engineering and fabrication is over the top. Mine on the otherhand is a virtual bolt in conversion that has been documented in great detail.
More information -
http://ecomodder.com/forum/showthrea...age-30256.html