I'm not sure, but I think the Tank Car runs on methanol. Doesn't anyone have a copy of that C&D where they drag-raced a tank?
Diesels do have a bad rep in the US, but me, I've seen the worst of the old kind (slow, smoky, noisy, nothing happening above 2500rpm) and some fine examples of the new kind.
The last two diesels I drove could pass 100 mph (160kmh) quite easily, and accelerate as well or better than gas engines of the same displacement. To be fair, yes, they're turbodiesels, but the Hyundai, with its variable geomtery turbine, has no turbo lag at all, and will happily ping off the rev limiter at 4500rpm all day. It feels like it could actually go to 5000+ rpm, but seems limited merely for the sake of longevity.
Of course, with diesels being so heavy, they're not going to corner as well as similar powered gas engines. From what I remember of the 120i and 120d, the 120d has way more straight line grunt (hence, it always gets faster lap times if there are any decent straights on the track), while the 120i feels more crisp and delicate around the corners. I pick the 120i over the 120d as a more exciting drive, personally.