I recently picked up a 21' Class C Toyota-based motorhome. It is a '92 with a 3.0 liter V-6 and overdrive automatic trans. My mileage so far has been 15.5, 17.2, and 15.6 mpg. This is on mostly flat freeways in western Oregon, at around 50 mph. It seems that it is always on the verge of downshifting, and whenever I encounter any grade, I either slow down or it kicks down into 3rd gear. Under slow acceleration it shifts into 4th (overdrive gear) at about 45 mph. One problem is that I always seem to have a head wind. I can tell because I have a little wind sock attached to my radio antenna
Actually I watch the flags and trees along the road to estimate wind speed and direction. Does anyone have any experience and/or ideas to improve mileage in one of these? I'd like to have a ScanGauge in it; I suspect that would help, but of course it is not OBD II.
I try to use driving techniques similar to the ones I use to get north of 50 mpg in my '96 Metro, except for coasting engine-off down hills. I haven't tried that yet. I don't know how the automatic trans would like that. I'm also considering removing the rooftop A/C for a little more aero efficiency. It's still got the aerodynamics of a barn door, but overall there should be many opportunities for improvement. All suggestions are welcome, short of melting it down to make a fleet of Prius's.
THX MCH,
Beaver