DOES DRIVING WITH AC CONSUME MORE FUEL
Answering this depends on the circumstances involved.
Bear in mind the manufacturers of any vehicle have factored in the load-carrying capacity of the engine with AC inclusive.
AC systems are independent systems aside from the engine but are attached and powered by the same engine while doing other work.
Once you put on the AC workload on the engine increases, the ECU of the vehicle will immediately direct the injector to push out more fuel to augment the load.
Now if the vehicle is on the highway and with AC on, the windows are all up making the vehicle more streamlined to resistance from air. Same time since the car is on the highway, automatically the RPM of the engine is already higher than the steaming value, above 1000 so the redundancy the AC should have caused on the engine has already been overpowered by a higher engine RPM at this time the car will consume less fuel but if the windows are down more air will be rushing into the car causing more resistance to movement of the vehicle thereby making the engine do more work in trying to overpower the air obstruction.
If you want to know how strong this obstruction force from the air is bring out your hand from the window while on speed and see how the amount of energy you will need to obstruct the air.
Then when you drive within town you make more use of lower speed and lower gears and with AC on at this time, the engine will consume more fuel.
But apart from this, other factors are involved. Some of them are the firing components of your engine. If the firing components of your engine is well detoxified, as in the nozzles, coil, MAF, air filter etc are at their optimum performance the engine may not even notice the AC is on. This is where bigger engines V6, V8, and V12 have an advantage over i4 engines. This engine hardly notices when you put on AC.
NOTE: When you put on AC how much your RPM drops is how much the effect and fuel consumption to that engine.
When your own drops much and the engine vibrates when you put on AC just know your engine is misfiring or has very low compression, so go and fix it.
You cant bring an engine that’s already having misfiring issues and expect it to comfortably power your AC without complain….no way.
©️Engr Gozie Atueyi.