I asked this before, but now that there are so many more RV-12's flying, I will ask again: What real-world fuel GPH are you seeing in CRUISE? I realize there are many variables, but your input would be appreciated. thanks
John this is a tough question because there are a lot of variables like you said. So Im going to give you the worst case scenario. If you have your prop set to produce as much speed as possible, you run max power, Altitude below 3000' msl, IAS 120kts, wheel pans installed (all 3) at or below 5500RPM, your fuel burn will be around 6.0GPH. After that the fuel burn only goes down as you power back, IAS110knts 5.3GPH, IAS100kts 4.8GPH, these are approx because of those stupid variables! Here is a link to a discussion on speed but note weather it is TAS or IAS. Does this answer your question?
I have 150 hours on mine including trips from Texas to Sun/Fun...OSH...Wyoming all high altitude (9.5 or 10.5) with the A/P with RPM's at approx 5100/5200 which is usually 75%. Considering total fuel used over those 150 hours I have averaged 4.25 cruise/taxi/climb/descent. The most efficient airspeed according to the POH is L/D at 87 knots with plus/minus for tailwind/headwind. Obviously you are well under 4gph at that airspeed. Another thing to consider is that if you travel extensively you are burning considerable AVgas vs MOgas. While it doesn't influence the gph it does cost more and generates more oil changes. I also have my prop pitch set right at 4900 RPM static WOT.