What you are talking about is the new Roadtrek engine generator. This will run the A/C and the microwave and works with the van engine idling. This is available for both gas (Chevy) and diesel (Sprinter) Roadtreks and replaces or is installed instead of the Onan 2800 watt generator which is independent of the van engine and runs on gas or propane. The engine generator is usually combined with a large capacity inverter and additional batteries or solar panels. The Onan doesn't need the inverter. The engine generator and batteries/inverter is a scaled down version of what is standard on the Etrek.
