Is Class A smoother ride then Class C and MPG

If you go for a Class A diesel pusher with an air bag suspension, yes you will get a better ride, but because it's bigger and heavier, your fuel mileage go down. We get about 6.5 miles to the gallon, but how many miles a year are you going to really put on it? These are diesel pushers and they have a quiet ride up front. If you have to run the generator at night, it's up front and you're in the rear.

If you buy a smaller class A, the weight will go down and the mileage will go up, maybe to 8 MPG. In 10,000 miles you'll save about 350 gallons. The smaller Class As though have a gas engine up front. More noise while driving and the generator is in the rear (usually) which may be a pain when trying to sleep. They also have spring suspension and ride rougher a DP.

Bill

Go take out a higher end DP for a ride.

I would weigh the rig loaded like you are going on a trip.
You could be overloaded.
If not then I would have the rig checked over.

Depends on make and model if it will be quiet or not, my class A is not so quiet and yes the cracks and bumps in roads are noisy and 8 mpg is considered good in a gas class A.

Also check your air presurre, if you have HD truck tires they do not need max air pressure, max pressure will ride hard.