The 2014 Formula 1 regulations mandate a fuel flow rate of 100kg per hour. The restricted flow rate also has a knock-on effect in that the engines don’t need to rev at higher rates as they have in the past due to the flow rate and the ERS unit providing supplemental energy.
What it also has done is created a fuel war in F1. It’s not that fuel hasn’t been important in F1 before but this year’s restriction really look to maximize the performance potential out of each drop of fuel.
With that in mind, I wanted to ask Shell some basic questions about how the fuel is impacting F1 this year. Nothing too detailed but simple, straightforward questions that might help us unpack the sport just a little bit more.
F1B: Why does the fuel behave differently in these engines than past years?
Shell: The fuel appetite of the 2014 engines is quite different to the 2013 versions. The previous high revving, port injected engines required a fuel that readily evaporated, was fast burning and whose octane was not the main requirement. The 2014 engines require a fuel that is resistant to knock (detonation) which is generally characterized by the octane of the fuel. The energy contained in the 100kg of fuel is also important for performance.
F1B: Why is it the end-of-straight speed that is impacted and not other places on the track?
Shell: At the end of the straights the cars are power and not grip limited. Absolute power is where the fuels have an influence, alongside economy.
F1B: How is Shell formulating or are you focusing on these new nuances to how critical the fuel is now and how you can impact the straight-line speed?
Shell: We work with Ferrari on fuel strategy, performing Computer modeling to define candidate fuel formulations for evaluation. The fuel requirements are a combination of high octane and high calorific values, e.g. trying to maximize the energy available for the 100kg of fuel.
F1B: What iteration of fuel are you on now with Ferrari? Still the third?
Shell: We have introduced 3 fuels so far this season with more in the pipeline.
F1B: Is it down to the consumption rate that impacts the lap time and how does that work?
Shell: The power available from turbo engines is proportional to the amount of air/fuel mixture you can introduce into the engine, which has to be added at the correct ratio. The energy recovered from the exhaust turbo can either be used to compress more air into the cylinders and hence produce more engine power, or used to recover energy by the ERS-H generator on the end of the turbo shaft. This is then used by the ERS motor which can produce up to 160hp for 33 seconds/lap. The fuel flow rate is limited to 100kg/hr at 10,500 rpm and above, so you cannot keep adding more fuel to produce more power.