When my AC is on, my car consume more fuel (more than 30% I guess) is there anything wrong with engine or AC?

[flashmark]

When my AC is on, my car  consume more fuel  (more than 30% I guess) is there anything wrong with engine or AC?

For an example, when I drive car about 10Km, the average fuel consumption is 10.

When I park the Car ( engine is in start mode and AC is on) I see average going down to 6 within 20-30 mins (Temperature set to 27).

Car model - Suzuki Swift 2010 (Japan)

Is this normal? 

[iRage]

How is your compressor ? It could be that your compressor is on its way out (gear mechanisms messed up or something) and it is adding too much load on ot the engine. How is the tension on the belts ? Did you get any work done to your car jsut before you started observing this ?

[flashmark]

1 hour ago, iRage said:

How is your compressor ? It could be that your compressor is on its way out (gear mechanisms messed up or something) and it is adding too much load on ot the engine. How is the tension on the belts ? Did you get any work done to your car jsut before you started observing this ?

Thanks.From where I can check these? from a garage or AC repair center? 

[iRage]

1 hour ago, flashmark said:

Thanks.From where I can check these? from a garage or AC repair center? 

For starters....does the car cool ? Are there any noises that can be heard when the AC gets turned on ? WHen you turn the AC on do you feel like the engine suddenly lost a lot of power ?

Beyond that...yes...you should go to a reputed garage and tell them your problem. It might be somehing related to the AC, or it could be something completely unrelated like bad plugs, coil packs, fuel filter, air filter, injectors, etc...and the car is actually not performing well (it is just that it gets worst when the AC gets turned on and the engine is under load).

[Davy]

I don't think there's anything wrong here to be honest. Because you're using the real-time average fuel consumption on the dashboard and come to your own assumption that the car is being 30% less fuel efficient. That is not a correct observation and assessment.

A car can consume around 20% more fuel with AC running. This depends on a lot of factors - even traffic conditions and outside temperature. 

1. What you should be doing is this:
2. Fill up full tank. Ask the pump attendant not to continue after first auto-cut-off. 
3. Reset trip meter. Switch off AC
4. Drive for at least 25km (so that your car consumes more than 2 liters as you say that your car usually does 10km/l)
5. Fill up full tank. Follow same procedures as first step.
6. Note the number of litres pumped and trip meter reading. Calculate km/l
7. Reset the trip meter. Turn on the AC. 
8. Drive for at least 25km with AC on (same route would be ideal)
9. Fill up full tank. Follow same procedures as first step.
10. Note the number of litres pumped and trip meter reading. Calculate km/l
11. Compare the numbers

 

[pantheraleo]

Just my 2 cents, since the car is parked and not moving, petrol is consumed but no kilometers travelled. Therefore the average consumption should increase, also the car is idling for 30 mins.

Edited May 2, 2022 by pantheraleo

[Gummybr]

20 hours ago, Davy said:

I don't think there's anything wrong here to be honest. Because you're using the real-time average fuel consumption on the dashboard and come to your own assumption that the car is being 30% less fuel efficient. That is not a correct observation and assessment.

A car can consume around 20% more fuel with AC running. This depends on a lot of factors - even traffic conditions and outside temperature. 

1. What you should be doing is this:
2. Fill up full tank. Ask the pump attendant not to continue after first auto-cut-off. 
3. Reset trip meter. Switch off AC
4. Drive for at least 25km (so that your car consumes more than 2 liters as you say that your car usually does 10km/l)
5. Fill up full tank. Follow same procedures as first step.
6. Note the number of litres pumped and trip meter reading. Calculate km/l
7. Reset the trip meter. Turn on the AC. 
8. Drive for at least 25km with AC on (same route would be ideal)
9. Fill up full tank. Follow same procedures as first step.
10. Note the number of litres pumped and trip meter reading. Calculate km/l
11. Compare the numbers

 

@Davy You must be kidding about pumping fuel every 25kms, we have massive ques to pump petrol.😜

Its the best way to check it.

 

Also I agree with @pantheraleonever trust the computer on the car, sometimes you could be looking at the instant fuel consumption, when the car is idling it burns more fuel, am sure once you start driving it should increase considerably. For example a car at a showroom or car sale will show a very low average fuel consumption as it doesnt run much and you just start the car for a few minutes and stop.

[iRage]

On 5/2/2022 at 2:45 PM, Davy said:

Fill up full tank

By fill up tank he means until the auto stop goes click...not the whole..shake the car and pump in as much ful as you can approach.

On 5/2/2022 at 2:45 PM, Davy said:

• Drive for at least 25km (so that your car consumes more than 2 liters as you say that your car usually does 10km/l)
• Fill up full tank. Follow same procedures as first step.

An easier and more common approach would be to dive for 100km and top up and see how many litres you used to drive 100km.

[Twin Turbo]

keeo

[Twin Turbo]

Just now, Twin Turbo said:

keeo

keep this function on   with the A/c.

 

[flashmark]

Today I went to car AC repairing place and technician I happened because of faulty AC condensor. According to him, need to replace it and cost would be around 25k