[hawk2100n]

Originally Posted by drmiller100

if only the laws of thermodynamics didn't interfere, we'd all be there.

Drrmiller is right. Thermodynamics will prevent this idea from seeing any real mpg gains. (the first law of thermodynamics says that energy cannot be created or destroyed, only changed) The small engine would have to have significantly higher BFSC values which won't happen. Even if it is diesel, small industrial engines are relative pigs when it comes to fuel consumption. There is no free energy. A turbo charger has the smallest impact but the gains from it aren't realized unless you can move to a smaller, more efficient engine with significantly less friction. Think turbo v6 or i4 a-la powerboost ford f-150. A turbo v8 that is otherwise stick will use more fuel most of the time. The only free energy you can actually get is solar. If you're in a pickup, then you can install a tonneau and cover it with solar panels and mount some LiFe batteries in the bed for a lightweight setup and delete the alternator at the same time. Then a sufficient motor could power a blower but it would be complex.

And there will always be losses associated with creating boost. You won't make 50 hp from 5 hp. It just doesn't work like that at all. You can provide enough air for your engine to make the 50 hp but the engine will have to add a lot of fuel for that 50hp