There are a few things you can do to achieve better fuel mileage in the motorhome:

Slow down. Driving at high speeds can create a wind resistance that will require more fuel while driving.

Refrain from excess idling when the motorhome is stopped. Idling is unnecessary for engine performance and will waste fuel. Also, avoid heavy acceleration.

Lighten the load. The more cargo you add to the motorhome, the more fuel is necessary to pull the weight. Keep the load as light as possible and evenly distributed.

Maintain the engine. Change the filters on a regular basis and use quality motor oil replacement. Keep coolant levels filled and charge air cooler fins clear. Regularly check hoses for leaks or kinks. Follow the recommended service and maintenance schedules, which can be found in the operator's manuals for the various components and systems.

Water in the fuel can damage the system. Change the fuel filter as recommended by the manufacturer. If water manages to travel through the primary and secondary fuel filters a misfire may develop and the engine will run rough.

Watch the tires. Riding on tires that have correct air pressures will help promote better fuel economy. Do not monitor tire pressures by sight. Use a pressure gauge to inspect air pressures when the tires are cold. Regularly inspect brakes to assure there is no drag.

Avoid stop and go traffic. Park the motor home and use the tow car to maneuver around town. Use cruise control when possible during highway driving.

Refrain from using the dash air conditioning system unless it is absolutely necessary.

If you practice fuel economy driving habits and still feel that the MPG is unusually low, there may be underlying problems with the vehicle. Inspect the transmission for slipping or gear lock up.

Change the fuel filter on a routine basis. Fill the tank at a station that regularly replenishes the supply.