The F1 season is up & running. The audience base keeps growing, a part of it due to Netflix. As all race fans, we might be tempted to argue which car is better or which driver is the best, but this blog is just not about that. We wanted to look at how much energy an F1 car consumes and go into details of how it will be used.

Lights out, here we go!

If you’ve owned a car or driven one, you might have heard about ICE, Internal Combustion Engine. To starters, this is the crux of how a car gets driven, by converting your fuel to motion. If you put a fuel like gasoline/petrol in a small enclosed space and ignite it, the gas expands releasing a huge amount of energy. This energy is converted to motion using pistons. Below is a picturisation of its working.

Now, all of the gasoline put into the car, which is nothing but fuel energy, can’t be converted to motion. As per the Carnot cycle(derived from the theory proposed by Sadi Carnot, a French physicist in 1824), it is impossible to create a 100% efficient engine. Can you guess the thermal efficiency of your car?
For normal cars, it’s just about 20%, meaning only 20% of the fuel you put it in is being used to move you from one place to another. Toyota Prius hybrid has an efficiency of 40%, which still means that more than half both the fuel’s energy is unutilised.

Now, how about an F1 car?

Here’s a split of how the Fuel energy is used in an F1 car:

In 2008, the F1 cars stood at 29% efficiency. As per Racefans, now it stands at a whopping 52% efficiency. What changed?

The usual notion is that more the fuel a vehicle uses, the better its performance is. Though it is incorrect, it was something that held in the automotive industry till the 60s & 70s. Lotus was one of the pioneers in making this notion false in the 1970s, well without much racing success. But various forms of engines were tried and by the end of the century, the F1 builders were sure that they had to make a car that uses fuel efficiently to win. And with sustainability and efficiency becoming the norm over the last decade, the efficient engine is something of utmost value now.

So, the F1 carmakers built something called ERS, Energy Recovery System, to recover the energy car lost. This is all part of the Power Unit which includes the Engine as well. What is inside the ERS?

This contains Motor Generator Units (MGUs) and is stored in Lithium batteries.
MGU-H: To harness the waste energy from the exhaust gas
MGU-K: To harness the waste kinetic energy from braking. In fact, a version of this is being used in our EVs now.

MGU-K harvesting is capped at 2MJ/lap (translating to nearly 15 electrical units per hour). MGU-H harvesting is uncapped.

Having understood the working parts of the F1 car, let’s look into fuel consumption:

Now, you cannot load too much fuel into the car as this increases the weight and thus requires more energy to move fast. At the same time, you cannot have lower fuel as the car might stop in the middle. But, can’t these racing cars have sensors that tell the appropriate level of fuel in the tank, which is so normal in our road cars?

Making that decision is not as simple as working out the rate of fuel consumption per lap and multiplying it by the number of race laps.

Variations in climatic conditions can have a strong effect on fuel consumption. In wet conditions, cars lap more slowly and therefore use less fuel. And teams will not know in advance of a race exactly how wet it’s going to be.

The F1 car tank’s shape is also one of the reasons, which makes it tough to tell the level of fuel inside, called “Fuel Slosh”. Here’s a video that offers a better view of how fuel slosh looks like

Fuel Slosh

Drivers also use fuel-saving techniques called Lift & Coast.
Let go of the accelerator and use engine braking to save fuel during the race, as opposed to flat-out driving.

This technique achieves a faster overall race time than would be possible by carrying additional fuel and driving “flat out” from start to finish. Teams deliberately under-fuel their cars because they expect their drivers won’t be able to go flat out at times during the race. For example, they may get stuck in traffic — this is especially likely for those in the midfield.

Coming back to our initial discussion,

How much energy does an F1 car use?

Formula One fuel would fall under high octane premium road fuel with octane thresholds of 95 to 102. From the 1992 season onwards all Formula One cars must mandatorily utilize unleaded racing gasoline fuel. F1 Blends are tuned for maximum performance in given weather conditions or different circuits.

F1 cars are allowed 242.5 pounds (110 kilograms) of grapefruit-scented fuel per race, which at gasoline’s usually energy density of 12,889 Watt-hours per kilogram (Wh/kg) brings a full tank’s potential energy to nearly 1,400 kilowatt-hours (kWh).

 

Since the average tank filling & usage is expected to be 80% of the limit owing to race conditions, we can say that it uses 80%*1400 kWh = 1120 kWh.