[CNGBiFuel]

Thanks 'classic' I have it now. In our three theoretical engines, petrol remains king, if by a small margin. Direct liquid injection of LPG could topple petrol's crown, however this is clearly is not an option with CNG.

So all the bullplop about higher octanes of the gases is all very well, but in practice it's not going to easily topple the issue of less energy per cycle in the first. But all this is a point of interest to me, but in the real world, entirely academic. I am glad you've cleared up the 'LPG runs hotter' point. That never made any sense.

I tell you what though, as I've said before, my Blackstone Labs test on my oil has it good for 30K. I suspect LPG is nearly as clean. Try that on petrol.

Thank you for your clarifcations.