This morning I posted a new Field Report on my priginal Post after returning from our 2200 mile Oregon trip yesterday.
The following is my comments on the "MR040"
Borrowed Engel MR040 40 quart fridge
Draws 3 amps when it cycles vs the MT35 that draws 2.7 amps. Not 3 amps steady. As you view the Trimetric the amp draw lowers to about 1.9 after 15 seconds then holds that number for 2-3 minutes than it clicks off.
The extra 6 quarts allowed us to carry all the food we needed for two for the 9 camping days. We spent 4 in motels. And the side opening gave us better access when the floor was covered with our outside items (2 folding chairs, stove, barbecue, drink cooler, porta-potty)..
Its great that it holds half gallon of milk upright. Kept ice 7 days in my quart container. The unit I borrowed seemed to be colder in the bottom almost like a freezer than the items on the top. I'm going to experiment with two thermometers when I receive mine in the next several days to see if that is true.If so I will build a small "box" to hold ice cream and ice cubes.
Plastic case
On the website under reviews a recent owner took it to Death Valley and reported no problems after the bad wash-board. There is a certain amount of pounding as a boat plows through the waves. Engel has always impressed me with the ruggedness of their products. And the Japaneese always over-engineer their products so I'm assuming it will hold up over time.