What is the chassis on a 1972 Winnebago Motorhome?
It could Be Dodge, Chevy or Ford, The Dodge's are Identified by a D in the model ie. D-20, D-22, D-24 and the same for ford F-17 etc.
Now I do not know that much about the Chevy Chassis so I cannot help you there.
Winnebago and Fleetwood probably have the best reputations of all of them. Of course, you want it to be built on a reliable platform, so you'll have to be careful of which chassis it's built on. You could have a great motorhome, but if was built on, say, one of the Econolines back when they offered the 6.0 Powerstroke, you were going to have a lot of problems.
Fleetwood doesn't make their own chassis, and they've always offered a wide range of models and classes of motorhome. As is, we don't know if you have a Class A, B, or C motorhome, meaning we don't know what chassis it was built on, and we don't know what the engine is. This info would be necessary in order to answer your question.
Freightliner doesn't make motor homes - they supply the chassis for them through Freightliner Custom Chassis, then they ship them to whichever customers... Winnebago, Fleetwood, and Allegro are among the purchasers of Freightliner chassis for motorhomes. As far as fuel mileage goes, you can expect between four and eight MPG... a lot of it really depends on your driving habits. These tend to use lower displacement engines than a semi truck, and are typically geared…
In simplest terms, the Class A motorhome uses a single body with a flat nose - they're often built on bus chassis, while a Class B uses a second body which is attached to the cab, and the cab has a hood which extends out from the front. Even a Class 8 truck (such as the Freightliner Columbia or Volvo VNL series) which is made into an RV is still a Class B motorhome.
General Motors released a yearly manual of wiring diagrams for the P-30 chassis. For example, the 1992 manual was entitled "1992 Electrical Diagrams and Diagnosis Manual Light Duty Forward Control Chassis, Value Van, and Motorhome Chassis Models". The GM document number for the 1992 manual was X-9240. They are sometimes available on EBay