Air Conditioner Fuel Consumption
AC vent In early cars like the 70s Peugeot 504 and other cars before that era when car AC compressors were bulky and not very efficient, it is indisputable that using your car Air Conditioner while driving means parting with some extra liters of fuel. But we are in an era when car compressors are better built and lighter. That doesn't mean they don’t require power from the engine to be driven as is most noticeable at low rpm like when the car is idling and you switch on the AC. The noticeable drop in rpm is mostly due to inertia. So, your glasses are down and your AC is off so you can save fuel. I bet the only place you are going to save that fuel in today’s cars is ‘in your head, not in your fuel tank’. If your glasses are down and you are driving at speeds in excess of 80km/h (about 55mph), the inside of your car will be working like a big balloon or parachute to pull your car back as air flows in through the windows. This way, the engine will be wor...