I have always heard people complain that turning car AC On increase fuel consumption. I always turn my car AC On and I don't see any significant difference with regards to fuel consumption.
Is this really true?
What's the physics behind it?

Oya, over to you, half baked Nigeria physicist

Yes it does

Your car electric system is powered by your alternator which is powered by your engine

Ac has pumps connected to condensers that uses power

The more the power usage the more the more your engine performance

To understand these... Always check your car RMP on the speedometer when the car is idle and you on your AC


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solmusdesigns:
Yes it does

Your car electric system is powered by your alternator which is powered by your engine

Ac has pumps connected to condensers that uses power

The more the power usage the more the more your engine performance

To understand these... Always check your car RMP on the speedometer when the car is idle and you on your AC


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He's talking about fuel consumption..
No sig diff cos your car is well maintained and when the ac is on, there's less "drag"

What is drag? Think of it like you're swimming through water, you need to push through water while a fish will swim effortlessly cos of body design

When you use your ac, all glasses are up and you don't need much force to push through the wind but In a the case where you have glasses wounddown, not just the body of the car is passing through the wind but the other interior components cos the wind enters the car. The car needs more power to fight through remember that other components are now involved

vastolord4:


He's talking about fuel consumption..
No sig diff cos your car is well maintained and when the ac is on, there's less "drag"

What is drag? Think of it like you're swimming through water, you need to push through water while a fish will swim effortlessly cos of body design

When you use your ac, all glasses are up and you don't need much force to push through the wind but In a the case where you have glasses wounddown, not just the body of the car is passing through the wind but the other interior components cos the wind enters the car. The car needs more power to fight through remember that other components are now involved

I am not talking about car drag

I practically fixed my car AC a four cylinder Honda EOD... I needed to work on the idle engine run as it is a manual

Low RMP and AC kills off the engine especially on hold up

High engine RMP makes the engine run but burns too much fuel which overall cost me more money

Automatic Cars have their slow running or idle regulated by the ECU so whether you have factory fitted AC on or not it consume same amount of fuel

solmusdesigns:
Yes it does

Your car electric system is powered by your alternator which is powered by your engine

Ac has pumps connected to condensers that uses power

The more the power usage the more the more your engine performance

To understand these... Always check your car RMP on the speedometer when the car is idle and you on your AC


.

what my ac is on on idle i still get between 650-750rmp regardless of ac or not. Car is till silent if you stand around the car you won’t even know of the engine is running. Most especially if the thermostat has not kicked the fan.

The only I know is a cold start the engine rmp at 1000. But once the car warm up it drop to 700rmp. Regardless of ac or not. That why i like v6. Those 4cyd and small engine struggles to power aircon

fineboynl:
what my ac is on on idle i still get between 650-750rmp regardless of ac or not. Car is till silent if you stand around the car you won’t even know of the engine is running. Most especially if the thermostat has not kicked the fan.

The only I know is a cold start the engine rmp at 1000. But once the car warm up it drop to 700rmp. Regardless of ac or not. That why i like v6. Those 4cyd and small engine struggles to power aircon

A four cylinder VVT used by Camry Big daddy and some Muscle are also like that..

The Idle is wired to the ECU Brainbox and it automatically regulate itself

But any mistake to tamper with the idle from the accelerator would cause problems

Anyways normal car owners don't need to lower idle or worry about fuel and AC

It's most UBEr and Bolt ride that need lower fuel

This arguement are for people wey get cars, I'm out

Well obviously there is a significant difference, try measuring Ur MPG with & without AC...

But depending on ur pocket, it might not mean much...But to me, for example an extra 5-10km of distance traveled without AC is much.. Though I never hesitate to use it in hot 🥵 weather.. Afterall, why should I be sweating inside car when AC dey functional