Auxiliary Transmissions Prevent RV Transmission Problems & Enable Motorhomes To Climb Hills

You're cruising down the freeway with a mild headwind and your motorhome on cruise control 

Unfortunately, the motorhome can’t make up its mind... in top gear it’s struggling in the wind, but when it drops a gear you're screaming at high rev’s.  One thing is certain: the gas gauge is dropping like a rock as it continually hunts up and down for a manageable gear.

Have you ever noticed, semi trucks have transmissions with 10, 13, even as many as 15 different speeds?  The reason for that is to give the driver the ability to pick the gear that allows the truck to roll along within the most economical RPM range.

An engine that’s screaming along is pumping as much fuel through it as possible, while an engine that is trying to pull too much of a load in too high a gear is also washing excess gas through the engine.  Both situations will consume excessive fuel, and cause excessive wear to the engine.

Gas motorhomes generally are equipped with 4-speed automatic transmissions behind a large cubic inch engine.  The weight of the motorhome is carefully calculated by the manufacturer to give you the roomiest (and biggest) RV within the limitations of the drivetrain powering it.  To keep manufacturing costs within reason, drive trains are limited pretty much to this type of offering.  If you want more power, you’ll have to go with a diesel pusher at a considerably higher price.

So what can you do when your 38-foot Class A motorhome -- which usually gets about 10 mpg -- drops to 5-6 mpg because of hilly terrain, or high wind conditions?