In the hybrid era, fluids — fuel, oil, lubricants, and coolants — have played a vital role in boosting performance. A look at how Mercedes and PETRONAS have got it right

Formula One is a sport of thin margins, with crazy money and resources invested in chasing fractions of a second in performance — margins that can define races.

A lot of the in-season development focuses on aerodynamic modifications, improvements in suspensions and brake ducts, and periodic engine upgrades. But an area of development that has grown in importance since 2014, with the switch to small, turbo-powered hybrid units, is the fluid that forms the lifeblood of the power unit: the combination of fuel, oil, lubricants, and coolants.

During the Italian Grand Prix, Malaysian oil and gas company PETRONAS offered The Hindu access to its engineers and trackside laboratory to get a sense of how the fuel supplier and the engine manufacturer work together to improve performance. Mercedes, in its time with PETRONAS as technical partner, has won five drivers’ and constructors’ titles and is on course this season for a sixth double. Mercedes had a head start in 2014 and was the engine to have till 2016, but Ferrari has fought back strongly since.

As outlandish as it sounds, the nature of the fluid determines something as fundamental as the car’s size. “Combustion produces a lot of heat and this has to be managed,” says Andrea Dolfi, head of R&D, fluid technology solutions, PETRONAS.

“[If you go beyond a certain limit], you will melt alloy and burn plastic. You typically dissipate heat through a radiator, but if there is a fluid which can efficiently dissipate heat, then the car can have a smaller radiator. This means a more compact car, reducing drag and boosting speed. So, you can see how a tiny thing in fluid can impact the whole design and engineering of other components of the car.”

What’s more, the excess heat is extracted and fed back into the car; the better the fluid is at recovering this heat energy, the more efficient the car. So, it’s no surprise that engine manufacturers have a close relationship with their fuel supplier, right from the design stage, to maximise power and improve lap-times.

Andy Cowell, MD of Mercedes AMG High Performance Powertrains (HPP), confirms that the power unit and its fuel “were designed hand-in-hand — and there was continuous exchange between us, in order to optimise not just the composition of the fuel and its combustion characteristics, but also the physical characteristics of the engine to ensure they worked together in the best way possible.”

Cowell also speaks of how teams in an earlier era of racing were rewarded for using more fuel to generate power; there were no fuel limits. “The hybrid regulations work with a maximum fuel flow rate — so the challenge is to generate as much performance as possible from the available fuel, which is the same for every competitor,” he says. “This means focusing on efficiency in every aspect of the power unit, both to generate power and also minimise the small losses that can cost lap-time.

“The regulations mean that we find performance through thermal efficiency — essentially, converting as much of the chemical energy in the fuel as we can into useful work. We then also focused on minimising any energy losses in the system, through our design choices and the lubricant specification.”

The fuel supplier also provides trackside support. During a race weekend, the only way to discover issues with the engine is to test the oil before and after each session.

“The engine is like the heart and oil is the blood,” says Dolfi. “Like blood tests, we use the oil to look into the engine because you can’t open the engine during the weekend. If there are some parts misassembled or there is excess wear or something wrong is getting into the engine, the oil can tell us and we can repair it.”

Just how does this work? The presence of metallic components in the oil corresponds to the wear of the part of the engine that is made of that metal. “For example, let’s suppose pistons are made of titanium,” says Ahmad Nasri Mohd. Shafie, PETRONAS trackside fluid engineer. “Whenever there is excessive wear of it, we will find high levels of titanium in the oil.”

While wear is expected, given there are so many moving parts, excessive wear isn’t: so, if there is a lot of something in the oil that shouldn’t be there, alarm bells ring.

We’ve learnt how vital fluid is, but just what difference does a fuel supplier make in terms of increasing power and reducing lap-time? “We wouldn’t like to put a number to this — as it simply sets a target for our rivals to aim for!” says Cowell. “Generally, it is true to say in Formula One that there is no single ‘magic bullet’ — we find performance in small steps… and these add together. The fuel and lubricants are an integral part of this process.”

Mercedes team boss Toto Wolff is more willing to put a number to it, without giving too much away. “PETRONAS are a performance contributor, but it does not come only from the fuel. Real horsepower comes from the oil and the heat-rejection efficiency from the fluids (lubricants), which translates into horsepower. So we are talking about double-digit horsepower from oil and fuel.” In a sport of small margins, that’s plenty.

(The writer was in Monza recently at the invitation of PETRONAS)