Although I rated it rather low, I still actually liked the movie. A runaway Cat possessed by a rock from the sky. Nice plot line, eh? I was a heavy equipment mechanic for many years and know pretty much everything about bulldozers and how they operate. A diesel engine requires fuel and compression to run. While this dozer is running around killing people I always wondered why nobody just shot the fuel injection pump. It would literally stop in it's "tracks". "Shoot the injectors. It's helpless with out them!" (a take-off of a line by Professor Medford in the movie "THEM!") Maybe being possessed by the evil spirit of a rock from space, it didn't require fuel. I don't know. Still a good movie if you have nothing better to do...like stick your face in a fan. If I was channel-surfing and came across it, I would watch it again, though That's how sick I am..