Additionally, I always hear how these Coaches e450 are so close to their ratings. And I agree they are. But really they are super heavy duty vehicles. The drive train in the E 450 is almost exactly the same, except for the 3 valve engine which is used on the Class A F53 chassis which will handle 26000 lbs.
It is made to handle some serious loads. At 19000lbs coming off a mountain, the e450 is handling 7000 lbs less than its Class A brethren. It's hardly huffing.
I also find when the Coach is fully loaded is when it drives and rides the best.