The Newmar Factory. www.newmarcorp.com On our way out of Michigan, we stopped in Nappanee IN for a Newmar Factory Tour. This is where our coach was built on top of the Spartan Chassis. The chassis comes as a rolling, running chassis including steel raised rails, electrical, fuel tank, engine & transmission and single rear axle (ours) with 4 tires out back or “tag” axle with 6 tires in the rear, and either I beam front suspension or Independent Front Suspension, IFS, (ours). It is interesting to see how they drive these with a seat on a stick!
They build all coaches to order, no “lot inventory” and are currently building 7 per day. And whether they are the least expensive gas model or the most expensive diesel pusher, they are on the same assembly line. They use a system of dollies on each wheel to manually push the chassis sideways to the next station, then around the inside of the building to the next station to the end in a U shaped assembly line. It takes 7 days to complete this process, no matter the cost/complexity of the coach. Each station has a specific function, like putting on sidewalls, roof, end cap, windshield, electrical wiring & standard features and options. All the sub assemblies, floors, walls, interiors, end caps and roofs, are prepped in the middle of the plant and moved to the correct place in the assembly line, “just in time” for using on that specific coach.
Obviously they use more people, equipment and parts on a King Aire diesel pusher than a Bay Star gas as they go down the line, side by side. There are 5 miles of wiring on a King Aire! 
One interesting tidbit is all trash and cut parts, like wiring, is swept to a conveyer belt under the floor thru a heavy duty drain gutter, that goes to the outside of the building to a trash bin. Also, Master Craftsmen do all woodwork in some of the Newmar buildings in the 50-acre complex. Note that in this Amish country there are more bicycles than cars for transportation to the plants.
The real difference in the time to build a coach is in the paint and prep. After the 7 days to assemble the coach, it takes about another 7 days to prep and paint a Bay Star or Canyon Star gas motorhomes. The Dutch Star and Mountain Aire take about two weeks in prep/paint with their more complex paint schemes. The Essex, London Aire and King Aire take from 21 to 30 additional days to prep and paint depending on the paint scheme and how many times it is painted for each color. The paint jobs on the King Aire are amazing to say the least. After paint each coach comes back to the assembly line and awnings are installed with final inspection and test drive. All coaches are driven to the dealer who ordered it.
They would not allow any pictures inside the buildings but you can tell from the long range pics the paint on the more expensive chassis is world class.
I’m sure other motorhome manufacturers use a similar process and from the looks of other new coaches they are good quality. But, having seen the Newmar process and final products they are some of the best in the industry.
A word about Cargo Carrying Capacity, CCC. Most single rear axle coaches on the road have a good chance of being overloaded. The Chassis manufacturer assigns a maximum weight for the coach, including maximum for the front and rear axles, depending on many factors. The problem is with the weight of the coachwork and options, including heavy woodwork and tile flooring, many single rear axle chassis only have from 1,500 to 2,500 pounds carrying capacity, i.e. your stuff. Newmar is now building tag axles on all 40’ and longer models for that reason. Tag axle coaches generally have 9,000 pounds or more CCC. The Sprinter-Mercedes chassis generally have about 1,000 to 1,500 pounds CCC, and the newer Ford V10 gas based “B” or “C” class motorhomes have about 4,000 to 5,000 pounds, which is good for non-full time RV’ers. If you have a motorhome, get it weighed so you don’t over-tax the chassis, engine and tires.