Fuel Efficiency at Different Fan Speeds

[abidkh]

Hello Fiends,

Does it affect fuel efficiency of a car if knob (encircled in the shown picture) is at 1 or 4 when car AC is ON?

[faridahmed]

it doesnt, since this is just blower speed which is electrically controlled or so
i guess the dial on the left makes the difference since this is what controls the thermostat

[arslansarwar]

Not at all. Not even 1%.
Instead using it at higher speed is better if your cooling is set to full.
It's like you have an AC running in room and you use your ceiling fan for better airflow.

[pwuser155177635611]

With fan speed 1&2 compressor will trip with 3&4 it will not... so there will be effect on fuel consumption . This is what my car does

[sfjsag]

Contrary to what most ppl think, it dies effect fuel efficiency.
Keep it at 1 or 2 and notice the AC tripping for longer periods and keep it at 3 or 4 and notice the AC blowing cold for longer periods.
I noticed that keeping thermostat at full cold and fan speed at 1 or 2 gives you better fuel efficiency compared to 3 or 4.

[Massive_One]

Does it affect fuel efficiency of a car if knob (encircled in the shown picture) is at 1 or 4 when car AC is ON?

Well most of the people say it doesn't, but i believe it does.

What i have noticed is, if i keep the blower at 1 , the engine fan trips on and off (now i am not sure also the compressor does trip on and off with the fan or is it just the engine cooling fan) and if i keep the blower speed anything above 1 the engine fan keeps on running and does not trip means constant running of compressor too .. (hence it requires more energy and burns more fuel)

[capsat]

What i have noticed is, if i keep the blower at 1 , the engine fan trips on and off (now i am not sure also the compressor does trip on and off with the fan or is it just the engine cooling fan) and if i keep the blower speed anything above 1 the engine fan keeps on running and does not trip means constant running of compressor too .. (hence it requires more energy and burns more fuel)

@SER_GTR @babarhyd @margallar

blower fan speed to control engine fan & ac compressor !

[Massive_One]

blower fan speed to control engine fan & ac compressor !

question : is it really NECESSARY that whenever the compressor is working, the engine fan will turn on ?

because in the early morning time, keeping the blower fan at 1, the engine fan turns off and on, but the A/C keeps throwing cold air (pardon my ignorance in this regard) : (

[capsat]

engine cooling fan function | on & off is controlled by the engine coolant temperature. even if you do not turn on blower fan & press ac button , it will work.
-
as member since 2009 with 1429 posts you have totally wasted your time instead of learning no wonder ! Sir always use search glass option to locate any query.

internet has destroyed the mental capacity of human to read & to study by reading actual books. not everything over google is CORRECT .. ! .. only actual books / manual can authenticate Google.

[capsat]

further -

The vehicles with single cooling fan over radiator. work through an small Temp ECU. It runs low when engine coolant temperature trigger it.

It runs automatic at Low & high speed when ac is also working.

[geek.maan]

is it really NECESSARY that whenever the compressor is working, the engine fan will turn on ?

of course -- whenever a AC functions, the condenser(grill) needs some fresh air to produce the 'cool' -- ever wonder why there is a fan in an outdoor unit of a home split AC? -- well Car ACs work on the same principle.

[Massive_One]

of course -- whenever a AC functions, the condenser(grill) needs some fresh air to produce the 'cool' -- ever wonder why there is a fan in an outdoor unit of a home split AC? -- well Car ACs work on the same principle.

So this means that in cooler ambient temperature, when the engine fan trips on and off, so is the compressor ? (while the blower is still throwing cold air)

[capsat]

in case of 2 fans - when ac is working both fans will remain active.

radiator fan will switch high & low. condenser fan will continue to run., on & off when ac compressor trip.

single fan .. will remain active between low & high

[Massive_One]

single fan .. will remain active between low & high

So this means that in cooler ambient temperature, when the engine fan
trips on and off, so is the compressor ? (while the blower is still
throwing cold air)

[arslansarwar]

Because at speed 3 and 4 the fan noise is high enough that you can't hear compressor tripping

[pwuser155177635611]

Tik sound is actually the ac clutch engaging and turning compressor on ... fan on and off also comensurates with that . Clutch sound is also heard in cabin i think . Other than fan that tik sound will tell you on what fan speed compressor engages more

[arslansarwar]

Well i never heard any of such sound in my vehicle. But despite of that, if you open the fan of your car with some screwdriver, and you trace down the links, you'll get to know that it has no connection with compressor at all. Instead it's just a blower who has a fan attached to a motor, and is throwing air comming out of compressor outlet. That's it.

Psychologically it really has a link to car's performance, whereas practically and electrically it works independently. That's the only reason you can even use it on your 12V battery.

[pwuser155177635611]

Faster fan means evaporator will lose cool fast slower means it will loose slow may be thats why .

[capsat]

@Xulfiqar offer your TROLL mode face palm for the rant

engine fuel efficiency vs cabin blower speed, please

[Xulfiqar]

aap ke pass panadol hogi?