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Few things provide greater relief than being able to turn on your vehicle’s air conditioning to counter the summer heat. But you’re probably wondering, ‘Does air con use fuel?’ This has been a debate among car owners for the longest time. If you’re someone who pays a lot of attention to fuel economy, you’d want to know if it makes more sense to turn on your air con or just roll down the windows. Stick around as we explain everything in detail and compare the pros and cons of using the AC.
Table Of Contents
Does Air Con Use Fuel?
Yes, air con uses fuel. Your vehicle’s engine is also responsible for powering the AC compressor, as they are connected via a belt. So, when you turn on the air con, a clutch engages and connects the compressor to the spinning engine, and this puts extra strain on the engine.
With a higher workload, your vehicle requires more fuel to maintain the same power output. So, in simple terms, the AC needs power; power comes from the engine, the engine burns fuel and this leads to your car consuming more fuel.
How Much Fuel Does Your Car’s Air Conditioning Use?
Your car’s air conditioning uses between 0.2 and 0.4 litres per hour. This is only an estimate, and it may vary depending on the make and model of the vehicle, as well as other factors. Research has shown that turning on your air con can raise your fuel consumption by 8 to 10%.
A good thing to keep in mind is that AC is most efficient when driving at highway speeds. There’s usually a higher fuel penalty at city speeds or in stop-and-go traffic.
If you’re really concerned about fuel use, check out our blog post to learn how automatic cars compare to manual vehicles in terms of fuel efficiency.
Air Conditioning Vs Open Windows: Which Is Better For Fuel?
Air conditioning is better for fuel than open windows. You may be wondering how this is possible since air conditioning directly uses fuel, and opening your window does not. Well, the answer lies in the ‘drag’ that driving with open windows causes. Opening the window while driving creates a drag that causes the engine to work harder to move the vehicle because of the air resistance.
It’s important to note that the drag and resistance problem only happens when you’re travelling at speeds above 50 mph (80 kph). So, it is more beneficial to use your air conditioning system in these situations.
However, open windows are more favourable for fuel economy when driving under 50 mph (80 kph). Travelling at this low speed won’t create the drag effect that increases your engine’s fuel consumption.
Do you know you can save fuel with engine braking and cruise control? We have detailed blog posts that explain the fuel-saving benefits of these features.
Factors Impacting How Much Fuel Your Vehicle’s Air Con Uses
If you’d still like to use the air con, you should know all the factors that determine how much fuel your vehicle uses. Here are the most important ones
- Outside Temperature: The AC system works harder to cool the cabin when it’s hotter outside, and this can increase fuel consumption.
- Cabin Heat Load: Your car will take longer to cool if it’s been sitting in the sun for a long time, and this causes your AC to work harder and use more fuel.
- Vehicle Size: Larger vehicles, like SUVs and vans, have more space on the inside, and this demands more from the AC and engine.
- Blow speed: Running the air con on its maximum or using certain vent settings can make it work harder than usual. Expect this to put more strain on the engine
- Driving conditions: Your air conditioning system is less efficient in stop-and-go traffic than on highways, where airflow helps cooling.
- AC system efficiency: A well-maintained AC system with clean filters and proper refrigerant levels will likely use less energy than one that you neglected.
- Compressor type: Modern electric cars sometimes have compressors that are more efficient than older belt-driven ones.
Remapping is another great way to tune your engine and get the best fuel economy from your vehicle. This is a better option than clutch coasting, which many drivers rely on for fuel efficiency.
Tips To Minimize Fuel Usage While Staying Cool
Now knowing the factors that impact fuel efficiency when using the air con, what can you do to minimise fuel usage when using the AC system? Here are some smart tips that work:
- Use ‘recirculate mode’: ‘Recirculate mode’ is a function in many vehicles that allows the air con to use the air already inside the car’s cabin rather than draw air from outside. You can identify the ‘recirculate’ button by its looping or circling arrow symbol.
- Vent before you drive: Open the doors or windows for 30 to 60 seconds before turning on the AC to release hot air trapped inside. This is particularly important on really hot days.
- Park in the shade: Keeping your car cooler to start with means your air con system won’t have to work as hard when you get in.
- Don’t set the AC to max unless you have to: Use moderate temperature settings to reduce compressor load and save fuel.
- Use the air con more on the highway: Open windows create drag at high speeds, so it’s often better to use the AC because it is more efficient on highways than in stop-and-go traffic.
- Maintain your air con system: Keep refrigerant levels, filters and system components in good shape to help the AC system operate more efficiently.
Hire a budget car from SDVH and worry less about fuel efficiency in city traffic. Our fleet features a wide range of cars suitable for various occasions.
Frequently Asked Questions
Does Using A/C Affect Electric Vehicles?
Yes, using A/C affects electric vehicles, but instead of using fuel, it affects battery range. The AC system gets power from the battery since electric vehicles don’t have engines. So when you use air conditioning, you’re using energy that could otherwise power the wheels. Using A/C in EVs can reduce driving range by about 5-15%.
Does The Outside Temperature Affect How Much Fuel The Air Con Uses?
Yes, outside temperature affects how much fuel the air con uses. Your AC has to remove more heat from the cabin air when it’s hotter outside, and this makes the compressor work harder. The harder the compressor works, the more power it draws from the engine, increasing fuel use.
Does Using “Recirculate” Mode Save Fuel?
Yes, using ‘recirculate’ mode can save fuel. Recirculate mode allows the AC system to use air already inside the cabin instead of pulling in hot air from outside. As a result, the A/C system doesn’t have to work as hard to cool the air, which reduces the load on the compressor. Since the compressor gets power from the engine, a lighter load means the engine burns less fuel, especially in hot weather.
Should I Turn Off The Air Con Before Turning Off The Car?
Yes, you should turn off the air con before turning off the car. Doing this can help reduce strain on the system when you’re next starting up the car, especially in older vehicles. It also prevents moisture from sitting in the air con system, which can reduce the chance of musty smells or mould. The AC is, however, designed to handle this automatically in modern vehicles, so it won’t cause damage if you forget.
Will Servicing My Car’s Air Conditioning System Improve Fuel Economy?
Yes, servicing your car’s air conditioning system will improve fuel economy, but mostly in situations where the system is not functioning as it should. The system has to work harder to cool the cabin when AC components like the compressor or condenser are dirty or worn. Regular maintenance helps the AC system run efficiently, which can improve fuel economy, albeit slightly.
Conclusion
So, does air con use fuel? It’s a resounding ‘yes’. The more important question should be, ‘How much fuel does your car’s AC system use?’ Air conditioning will always use fuel since it draws power from your vehicle’s engine. However, turning off the AC and rolling down your windows isn’t always the best option for fuel economy. It all comes down to the situation and your driving speed.
