Most dual a/c systems in passenger vans simply "T" the low side of the refrigerant to two evaporators, one in the front and one in the rear. There is still only one compressor, so increased fuel use would be marginal. Some big vehicles like buses have multiple compressors that would use more fuel with both systems in operation.
A little, the ac pump will put a draw on the engine more than without the ac on.
Driving with the windows down and AC off at lower speeds is more fuel efficient. At higher speeds(45+), having the windows down will create more drag and it is more efficient to have the windows up with the AC on.
OFF! -Burn more calories by sweating them out... sorry, but that's the truth.
Dual convertor means it converts ac to dc and again it converts dc to ac this phenomenon of converting two types of signal are in the same circuit is called as dual convertor
If it is a factory ac the front and rear use the same ports. It just takes more freon for one with dual units
yes, because the ac runs off the engine and puts more stress on your engine and has to work harder.(work hard waste gas)
More than likely the gas has water in it.
yes it does it makes the engine run at a higher rpm to run the ac compressor
Yes. But if you try to save gas by turning off the ac and drive with the windows open you will change the aerodynamic properties of the car so that its air resistance is higher and it will therefore use as much (or more) gas as with the ac on (and windows closed).
3.25 lbs
Depend on if it is single or dual ac system
More than likely the gas has water in it.