Wow that's neat! And it can keep up with fuel engines on the highway with out problem?
This is really interesting to me.
IF the engine is built with propane in mind yes they perform.
It does run hotter than gas so hardened exhaust seats are a must. Also helps to run the big thick bronze valve guides rather than tyhe cast guides with the bronze liner. This pulls the heat better.
Lots of bad rap on propane because many of the early conversions were dual fuel. This is a terrible compromise and the performance suffers with either fuel. Pane runs timing more advanced, and really important is that it advances really quick.
Propane doesn't create excess heat when lean, like gasoline does. It just doesn't make good power.
If you run it too rich it will create more heat, but it's easy to determine if it's too rich because you need to pinch your nose closed.
Again, the main thing is the high compression. Compression = efficiency = economy = power = low emissions.
And the tree huggers smell your propane and they all bump you up a few points as a more 'evolved' human lol.
I used to get love from them when I was driving my old beat up 88 chevy van. You could see the headers hanging down! 60 series
tires that were bald from burnouts from my 10.1 383.