The short answer is yes, your car aircon is using fuel. However, it doesn't use as much as you think and in some cases, it's actually more fuel efficient to run an aircon than it is to have your windows down.
In their test conditions, they found that running AC was less fuel efficient than having the windows down. The test studied an SUV and a sedan at low, medium and high speeds. Not surprisingly, both cars were the most fuel-efficient with the AC off and windows rolled up.
The short answer is yes - air con does in fact increase your fuel consumption and use more petrol. Research suggests that by using your air conditioning in your vehicle, you can increase your fuel consumption by around 8-10%.
Despite many believing this is a common misconception, air con does in fact increase your fuel consumption. Research has found that by using your air conditioning to control the climate of your vehicle, you can actually increase your fuel consumption by around 8-10%.
So instead, turn on your car's air conditioner on highways when driving the vehicle at higher speeds. This way, the engine will generate substantial power to operate the air conditioner. Since the drag will also be higher, keep your car's windows closed to save fuel costs in the long run.
Overall, both studies showed that driving with the windows down has a significant negative effect on the fuel efficiency — more than using the vehicle's air conditioner [source: Hill].
Cruise control can help you become more fuel-efficient and can help you save an average of 7-14% on gas thanks to its ability to maintain a continuous speed. In comparison, the constant change in acceleration and deceleration of the driver placing their foot over the pedals can eat more gas.
How Much Gas Does a Car's Air Conditioner Use? Switching on your car's air conditioning system will use some gas. There are estimates that the air conditioning system will lower mileage by about 3 MPG.
Please do NOT turn on A/C as soon as you enter the car. Open the windows after you enter your car and then after a couple of minutes, turn ON the AC. Here's why: According to research, the car's dashboard, seats, a/c ducts, in fact ALL of the plastic objects in your vehicle, emit Benzene, a Cancer causing toxin.
It might not seem like it would make much of a difference, but believe it or not, using air con can increase your fuel consumption by as much as 10%, and opening the windows when at higher speeds can increase it by as much as 20%.
Speeding increases fuel consumption and decreases fuel economy as a result of tire rolling resistance and air resistance. While vehicles reach optimal fuel economy at different speeds, gas mileage usually decreases rapidly at speeds above 50 miles per hour (mph).
In short, yes, but not really enough to matter, according David Bennett, manager of repair systems for the American Automobile Association (AAA). “The AC system, when operating, does add a slight load to the engine, which could slightly increase gas usage,” he says.
4. Set A/C to the coldest setting. Your car's air conditioning is most efficient when set to the lowest temperature and adjusting the fan for comfort. Most air conditioning systems cool the air to 3-4 C.
First things first, yes, it is more efficient to leave your air conditioning on. This doesn't mean what many people assume, though. You shouldn't be leaving your air conditioner on full blast 24/7 by any means.
About 55 miles per hour is the optimum speed for most cars. Kick it up to 65 mph and you are 8 percent less efficient; at 80 mph you are 28 percent less efficient. Slowing down can also mean reducing your carbon footprint.
The Energy Saving Trust says that the most efficient speed you can travel in a car in terms of achieving the best fuel economy is 55-65mph. Any faster, though, and the fuel efficiency decreases rapidly. For example, driving at 85mph uses 40% more fuel than at 70mph (oh, and it's illegal too). 8.
Typically, cars are most efficient at 45-50mph. As well as fuel economy differing from vehicle to vehicle, it is also dependent on a number of other factors such as tyre pressure, presence of roof racks, and driving style – all of which are covered in this guide.
It is highly recommended that you close all windows and doors when the air conditioner is turned on. This will keep the cool air inside the room and keep the temperature moderate. In addition to cooling efficiency, leaving the windows open will also put stress on the air conditioner.
Open windows once the weather cools
If you live in a cooler, northern climate, where late summer outdoor temperatures average around 70 degrees or less in the evenings, then you could see the benefits of turning off the AC and opening windows, as long as humidity levels are low.
However, the Environmental Protection Agency and Department of Energy says running your AC in high heat can reduce your fuel economy by as much as 25%. For a car that typically gets 30 miles to the gallon, that's like losing seven and a half miles.
Drive smoothly and at the best average speed for MPG
As such, if you can make your speed changes more gentle, you'll create a slightly higher average speed, and see fuel economy improvements.
Anything that is listed as less than 6-litres/100km or more than 16.5km/1-litre is considered to be pretty good. The first (and most common) reference is litres per 100km (litres/100km). This is how many litres of fuel the car needs in order to travel 100km. You'll often see it referred to as 'fuel economy'.
The compressor requires energy to run your vehicle's air conditioning system and so will use a small amount of fuel whenever the system is running. It could increase your fuel usage by as much as 10 per cent, and the effects are particularly noticeable on short journeys.