Re: I'm wondering why a diesel powered RV costs so much?
Doug,
Your price difference between the gas powered class A and a pusher seems a bit on the high side, assuming that you were looking at the same basic motorhome on each chassis. Based upon the prices that you list, I would guess that you are looking at used RVs? To really compare you need to look at make/model units that are available on either chassis and it will tell you a great deal.
To put it quite simply, the cost of a new chassis for the diesel pusher is about $35K more than the cost of a gas powered chassis for the exact same motorhome. The reason is that the diesel engine is more expensive and requires a different transmission. Both the engine and the transmission for a diesel weigh more, even if the same power ratings. For that reason they also require a different chassis structure that is made of heavier materials and that is much more stiff. And since the chassis now weighs much more, it also has to have a higher GVWR in order to carry that same motorhome, so that adds even more to the cost because it now must have a different suspension and axles and such. Since the entire thing is to cost so much more, the manufacturers nearly always now add an air suspension system and air breaks, which also are more expensive to build than what is found on a gas powered chassis. In addition, the design to cool the engine and transmission is more expensive when it is in the rear and can't use the force of wind over the RV to supply cooling air movement.
In short, the diesel chassis is much more complex and expensive than one powered by gasoline. It is also true that most diesel engines will out live the gas powered one, but a properly cared for gas chassis will last easily 100K to 150K miles. The pusher found in the more common motorhomes today should last more like 200K to 250K while those powering the big bus conversions will easily run for 500K or more.