I run a dwarf car and have had Gen1, Gen2 and now a Gen4. As far as using these engines in a car the Gen1 had the best power delivery for our 1000 lb car. Gen1's still have great success, Gen2's are a close 2nd. Have not run a Gen 3, but from what I can tell it is the best package for a car. So far, I don't like the Gen4. No Bottom end, but great top end. For circle track racing it has not been great. We have won some races and finished well in National races, but I'm just not there yet.
Randy
Randy