Posted on July 18, 2014
By James Allen
With the introduction of the new hybrid turbo engines to F1 this season, the emphasis was always going to be on efficiency at the same time as racing flat out.
The engine builders performed miracles to produce a power unit which, with the engine and Energy Recovery System combined, generates roughly the same power as the old V8 engines, but using 35% less fuel to do so.
Each driver must now cover the 300 kilometre Grand Prix distance with 100kg of fuel or less.
The “or less” is significant here because every kilo of weight you carry in an F1 car costs you 0.03 seconds per lap on a typical F1 track. Multiply that by 70 laps, and you are costing yourself 2 seconds over the race distance. That can be a winning margin in some races.
So given the maximum fuel limit and the penalty for carrying the extra weight, no wonder the subject of fuel consumption is vital in F1 this season.
Going the distance
At the start of the season, there were fears that the new hybrid engines might struggle to cover the race distance in Melbourne, given that Albert Park is one of the highest fuel consumption circuits of the season and that the technology was all so new. In fact the racers were helped by the deployment of a Safety Car, due an accident, which meant that the field covered five laps at reduced speed and that brought everyone safely within fuel limits.
Another tough circuit on fuel mileage is Montreal, Canada, which hosted Round 7. Here the Mercedes of Nico Rosberg had a faulty Energy Recover System in the second half of the race, which meant that, with no power boost coming from the hybrid system, he had to use more petrol than normal to maintain racing speed. Yet he still made it to the finish in second place. This was an indication of how much the engine makers are progressing with the technology.
How the race fuel strategy is managed
The teams have very sophisticated fuel strategies for the Grands Prix, which predict constantly what fuel will be left at the end of the race.
The normal strategy is to go as fast as possible in the early stages of the race, burning fuel and then to consolidate in the later part of the race, running at a deficit and using driver techniques like “lift and coast” into corners, which save fuel.
Everything is set to targets and is calculated on a worst case scenario, so that if the driver finds himself in clear air he is allowed to push hard and burn off fuel to maximise performance and minimise fuel weight carried.
There is a real emphasis on the driver in this hybrid formula; there is a premium for a driver who can save fuel behind a safety car and a premium for one who, when going quickly, can also save fuel in order to push hard at the end.
As the season goes on, it is a linear progression of improvement in fuel consumption; F1 regulations ban the development of the power units for performance and efficiency, but by getting better at interpreting data, making accurate predictions, improving driving techniques and refining all the processes and modes used on the engines, teams gain confidence to run close to the minimum limits on fuel. Already some cars are starting races with 98kg of fuel, saving themselves 4 seconds over a race and that will come down further in time.
Williams stand out, but why?
One notable talking point has been the performance of the Williams team, using the Mercedes engine this season for the first time.
Fuel consumption data consistently shows that Williams has the best fuel consumption of all the F1 cars in the race. Yet, as they use the same engine as Mercedes, Force India and McLaren, how can this be?
Perhaps the answer lies in the straight-line speeds, which are always among the highest. Williams designed its car expecting to use a Renault engine, but made a late switch to Mercedes only in the later phase of car development.
In other words they clearly designed the car to be low in drag, working to one set of power and efficiency figures, but the superior performance of the Mercedes meant that this meant they were both faster and more fuel efficient.
On this basis it is possible that the Williams will be very competitive in Monza, where straight-line speed is everything.