The running it every now and then applies to both gas and diesel. You should drive it far and long enough to get everything up to operating temperature and then some. As above, a nice 20 mile run should work for either, and while you're at it, run the generator for the same reason you are driving the mh. Of course none of this helps you with how often you use the thing. We purposely park ours in our driveway as a reminder to us that the mh is in the wrong place! It needs to be on the road or at some campsite. This was true when we had a fully paid for unit, more important now that we are making payments.