So, things have happened in the last 2 weeks. I got a SG - yeeeeii
And it turns out, it is all worth it. I already had a vacuum gauge installed, but the SG showed me that I didn't know how to use / interpret the vacuum gauge.
With a little SG, a lot of P&G and some DWL, it seems that I am going from a 27 mpg city driving, to an unbelievable 38 mpg city driving. Not 100% sure of that, but that's what the SG indicates. I just filled up the lpg tank and I'll have to wait for the next fill-up for the official numbers.
So all of this is city driving - I can't wait to get a chance to test it on the highway.
Great tool this SG - it does open your eyes on stuff that you thought you knew. Also, it's addictive