Why do Formula 1 drivers run out of fuel?

Bit of a random question I know but we wanted to address the question none the less. It seems surprising that for a such a precision sport like motor racing so many Formula One drivers run out of fuel – it’s happened already this season for Mark Webber who ran out of fuel in qualifying in China and concerns about fuel consumption hampered Lewis Hamilton’s race in Malaysia as well.

For decades, Formula 1 teams have known that they need to keep the fuel in the car to an absolute minimum in order to decrease the car’s weight and improve overall lap times. So getting the fuel level right isn’t a new problem for F1 drivers. Over forty years ago Jim Clark’s Ford Cosworth DFV ran dry at Monza in 1967 on the final lap and Lotus owner Colin Chapman was so obsessed with saving weight and using as little fuel as possible that his mechanics took to topping up the cars with a few extra litres of fuel when his back was turned.

In 2009, a ban on in-race refuelling was introduced which means that fuel calculations need to be more precise than ever. The F1 teams have to work out the fuel amounts before the car goes onto the grid. But it’s not a simple equation of fuel consumption per lap times the number of laps. Climatic conditions also affect fuel consumption – on a wet track cars lap more slowly and use less fuel, but teams don’t know how wet a track will be.

This is where the problem occurred for Hamilton in Malaysia as pre-race the track was really wet, but it actually dried up really quickly during the race meaning that the drivers used more fuel. Everyone was using slick tyres by lap nine and Hamilton was being urged to save fuel over the radio from that point on.

Whatever the weather conditions are, there’s still an overriding desire to put in the bare minimum of fuel. It’s said that some cars set out on the grid with 10% less fuel than they would need to complete the race flat-out which could save up to 15kg of weight on some of F1’s tracks. This isn’t as foolhardy as it sounds though, because the teams can anticipate where drivers won’t be able to go flat-out for the whole race – when they’re mid-field, for example. Deciding how much to fuel an F1 car is a risk versus reward balance. Risking coming to an early stop is a big risk to take, but the temptation to shave off time by under-fuelling is great.

It’ll be interesting to see what happens in Austin, Texas and Brazil during the last two races of the season. Red Bull-Vettel have little to race for so may experiment, but Vettel is an incredibly short-priced 2/7 with Betfair and others to win in Texas. Yet Red Bull could well experiment further with fuel reduction – which could also make a mockery of those tiny odds; time will tell.