I understand what you mean about the OBC. I don't know how accurate it can be either. I wasn't questioning your judgement or anything like that, sorry if I came across wrong.
What I had meant to include with that last post I made about the station wagon with the "Economy" gauge, was that I remember the service tech telling my stepmother about the guage being just a vacuum guage. All it did was monitor vacuum, and when you were lead-footing it, it would swing to "Poor"...
I had a 1965 International Scout that did the same thing, only the "economy guage" was the vacuum operated windshield wipers....when I lead footed it, the wipers would stop, mid-swing, wherever they were on the windshield..
It was pretty cool, you could turn on or off each of the two wipers individually, so they didn't swing in unison, either. One might stop halfway up the window, and the other might have been all the way up or down...
As for the acetone thing, I believe I am seeing some increase in mileage.
The first day after I put in acetone, the mileage went up from 17.4 to over 19.
Overall, it is hard to tell so far. My fiance' has been driving the Liberty more lately, and she has a lead foot. After a couple swings around town with her driving, the mileage drops a couple MPG, then I have to drive it a day or so to bring it back up...
Overall, in mixed town, and rural highway, mileage, I have seen about a half mile per gallon increase, which I have to believe would be more if the fiance' would keep her foot out of it!
I will be making my first highway trip (since the acetone) to Albuquerque in a couple days. I will be interested in seeing the result.