Fuel gains in Formula 1 are becoming harder, but more important, as teams attempt to extract the maximum performance potential from their respective packages.
Formula 1 has clamped down on fuel and power unit development in recent years as part of cost-cutting measures and a desire for greater convergence among suppliers.
No fuel updates were permitted through 2020 while for 2021 just a single fuel specification is allowed by each supplier.
While widespread attention is placed on chassis and power unit development fuel can also optimise performance for Formula 1 teams, assisting raw power and increasing efficiency, while potentially facilitating new design paths owing to the scope for revised engine and cooling specifications.
Ahead of the Bahrain Grand Prix Red Bull Racing’s fuel and lubricants supplier ExxonMobil introduced an update for Honda’s RA621H power unit and expressed confidence that it has delivered substantial gains.
“Normally whenever a new engine is introduced, we bring a new fuel along with it,” ExxonMobil’s Trackside Technician Sean Dunnett explained to MotorsportWeek.com.
“It’s not a simple case of finding any fuel to match the engine, it’s a development cycle that goes on right from the middle of last year and through the winter.
“We send up to 10 different varieties of the fuel to Honda in Japan to get those tested and approved to work out which one gives the new Honda engine the absolute most power.
“We are out to get the highest energy density we can have in the fuel, and obviously if we can achieve that and get a really powerful fuel then we can obviously help the team with the way they pack the car.
“If we can limit the fuel we have in there, and enable Honda to reduce the power unit size and affect the way the engine is cooled, [then] we can affect the bodywork. You can see on the RB16B the way they have packaged it compared to previous years is super, super narrow going over towards the rear.”
“We’re only allowed one fuel upgrade so the pressure is on us to provide the power, the performance and also the endurance, [as well as] the ability to look after the engines for 3-4000km as well.”
Formula 1’s power units have developed to the extent that a current-spec hybrid being put up against a 2014-spec unit would be seconds per lap faster. That improvement, and gradual convergence, means everyone is in the scope of increasingly limited returns.
“When you look at the fuel, engine [and] car together, that partnership has brought significant gains,” he explains. “It is getting harder now as obviously the gains are more marginal.
“It is harder to find those larger gains you saw in years one, two or three, of that work, and I think Red Bull and Honda will rely on us even more, to find those fractional gains, whether it be development from Red Bull or Honda or us, we all rely on each other to give the best package possible.”
Attention, though, is already switching to 2022, when fuel must contain 10 per cent sustainably-sourced ethanol – up from the current 5.75 per cent – while longer-term decisions also need to be made.
“A lot of the learnings we’ve had over the last few years are all starting again, the rule books are resetting with the increase to 10 per cent ethanol,” explains Dunnett.
“It provides us with a challenge in a sense the energy density and the power we’ll get from the fuel is less. Obviously there is a power deficiency to overcome but there are gains in other areas that we feel we can exploit.
“It’s up to us to put forward our best fuel. I think there will be more gains potentially next year with the way we can develop the fuel, they’ll [Red Bull] be looking to us to help them overcome the initial drop of power they may foresee happening.
“[Looking to 2025] obviously the FIA can’t just set rules which the engine suppliers don’t agree with. And there has to be an agenda for the fuel supplier. ExxonMobil’s [agenda] is very much to keep it commercial. I think a lot of fuel suppliers are aligned in a sense of they’re all in it for commercial benefit and they all want to see the rules guided… obviously with a sustainable sense in mind.
“I think it’s naïve to think you can shy away from the pressures coming within Europe to make fuels ever more sustainable, to look at synthetic fuels, [and] raising the ethanol content in fuels. There’s lots of things to look at but I think we’re far away from what post-2025 looks like.”