I logged every single fuel up in my 1987 Toyota 4x4 Extra Cab over the 300,000 miles I put on it. I watched my MPG drop to 22MPG, from a consistent 25 MPG on ethanol based gasoline. For years, I would be shocked to start getting 25 MPG again when leaving the state of California and filling up with gas in St George UT. Without fail, I'd start seeing 25 MPG every fill up on these trips when filling up with real gas, not cut with MTBE or alcohol. Both of them are fluff, filler, with no real calories for the amount of weight you haul around with them in your fuel tank... they just don't generate as much energy when being burnt.
My log sheets didn't lie. The Toytota had fuel injection, so I can't say much about the fuel lines, but I did run Techron pretty regularly.
I've zero love for alcohol being blended with gasoline, dumbest idea since the square peg being tried to be fit in the round hole.
And you can bet your little Honda EU2000i makes less beans running alcohol based gasoline, and consumes fuel at a higher rate also, trying to spin that generator, and wants to overload sooner too, with less watts being produced... yeah, possibly 10 to 15% less, just like in the car.
