Sorry to come to this thread late!
We have a 2011 Coachmen Prism, bought new, have driven over 18K and are very pleased with it. Currently we get about 14 mpg. The tank is 25 gallons but will read empty when around 20 gallons are gone. The manual does say that there is about a 5 gallon reserve. Headwinds give us lower mpg results, but rear ones improve our gains.
There have been a couple of issues. The main one required us to replace the retractable stair unit. It turns out that I was supposed to oil (with WD40 or similar product) the underside periodically (every 2-3 months).
It's in the manual, in tiny print! I've added some improvements (IMHO);
- 1. a 1000 watt inverter
- 2. A portable solar panel, 130 watts
- 3. An additional battery
- 4. an awning shade
- 5. a color rear view camera
I will be replacing the analog heat only thermostat with a digital display and am thinking of adding a swivel seat adapter to the passenger side seat.