A gas coach can have as much as 1/3 of the coach hanging out behind the rear axle with might include all the liquid load (gas, fresh and waste water). Last time I had my gas coach weight checked came in at 15.5K Lbs. 10K of that was on the rear. Front to rear weight distribution is going to vary between various models and manufactures but I think overall this might be a draw in the DP/Gasser battle. Also I really, really, really try to avoid getting into situations where I might be concerned about the traction of the drive axle.