Thor Forums

[Chance]

Originally Posted by dstankov

That alternator driven by a belt on the engine is drawing anywhere from 1 to 5 HP from the engine. This means the engine must run at higher RPMs to maintain the same speed over a given distance.

....cut.....

The engine would most likely run at same speed but slightly higher torque to produce the extra power. Large motorhomes like yours cruise at roughly 100 HP on level roads, so an additional 1 to 5 HP would not necessarily require different gearing or downshifts just because of relatively-minor extra alternator load.

Even if there was EPA testing, the second alternator like Mercedes supplies the mounting bracket for can be installed by the RV manufacturer, just like they add generators. Even if Ford supplied the second alternator/generator it wouldn't affect MPGs as long as a load wasn't placed on it. Without the house AC running off the 110-Volt inverter system it wouldn't put an extra load on the chassis' engine (for all practical purposes -- extra weight of alternator is insignificant).

In any case I'm fairly certain that total fuel consumption while driving down the road would be lower than running a generator at close to 1 gallon per hour. It's tough to see the government preventing this from happening solely from an environmental basis.