One of the biggest areas of performance gain in Formula 1 each season is the fuel run in the different power units. Around Europe and in the USA plastic-bespectacled lab-coated chemists fight an all-out war to extract the most from the 1.6 litre V6 turbocharged engines used at each Grand Prix.

It is an often repeated myth that F1 cars run on 'pump' fuel - in other words a product which you can buy on a forecourt - but the fuel used in Formula 1 is not the same as that in reality. Yes a Formula 1 engine can be made to run on fuel from a forecourt but it will lose a significant amount of performance (30-40bhp or more) and probably not be as reliable as the four power units per year rules require. Indeed real 'pump fuel' in other words that which you stick in your road car may not even be legal in Formula 1.

This is partly because at least 5.75% of the fuel used in Formula 1 must be a bio fuel while in the UK the fuel sold on the forecourt only needs to have 4.75% biofuel content. In other words F1 cars run on E5.75 or better while in the UK you may be running on E4.75% but E10 will become mandatory since, by 2020, it's likely that the EU requirement for biofuels will increase to 10% and Formula 1 will likely follow this progression.

According to Total which supplies Renault with the fuel for its power units (as used by Red Bull and of course, Renault in 2016) its F1 fuel is made up of about 200 different substances from the gasoline refining process, these fractions (as in fractional distillation) are selected like a kit of parts to build the perfect fuel for each iteration of the 1.6 litre V6 turbo combustion engine. This work is centred on the combustion chambers where F1 engineers are pushing the limits of what is possible in terms of the chemistry.

The Formula 1 power unit engineers are striving for 100 per cent thermal efficiency something which if they achieve will give the cars 1,600bhp or more. But unless someone makes a major scientific breakthrough this is unlikely and the combustion engines remain only about 43-47% efficient.

However the power unit manufacturers are working extremely closely with fuel supplier to improve that number, Ferrari with Shell, Mercedes with Petronas, Mobil 1 with Honda (McLaren) and Renault with Total. The level of collaboration and input of the fuel partners has a huge impact on the cars overall performance. It has been suggested that in 2014 much of McLaren's poor form was due to using Mobil 1 fuel in an engine optimised for Petronas products. Williams may suffer the same issues if it ever tries to run a Petrobras fuel in the Mercedes engine too (to date the Petrobras F1 fuel remains 'in development').

Just how engaged a fuel supplier is in Formula 1 makes a major difference to how it performs on track, Petronas is known to have spent a vast sum of money on its Formula 1 products (which are developed in Italy not Malaysia), the same is true for Shell (made in Germany) and to a lesser extent Total (Lyon, France - lovely food). Mobil 1 (USA) used to have vast R&D too when it was working with Mercedes but seems a little less engaged with Honda.

Both Mercedes and Ferrari had notable boosts in performance in 2015 due to fuel developments, Mercedes brought in a new fuel late in the season while a Ferrari combustion upgrade would have been 'impossible' without a new shell product.

'The possibility to improve performance with the V8s was always there with the fuel, but the opportunities then were probably that much greater with the oils. We have seen with the new power units that the balance has significantly shifted, the new V6s are incredibly responsive to fuel, they have a different appetite for fuel to the V8s and that is an area where we have exploited our experience with turbo engines from other areas of motorsport' a Shell spokesman told the press during the 2015 season.

While there were major fuel upgrades there are small ones too, each track has a slightly different demand in terms of fuel, Mexico with its high altitude, Monaco with its torque demand and Monza with its long periods of full throttle each have differing requirements. Generally the fuel suppliers claim to keep a consistent spec through the year but the reality is that there is circuit to circuit variance in the exact formulations and the batches produced are relatively small.

Once a fuel formulation has been chosen and validated by Renault Sport F1, Total puts it into production and stores in numbered and sealed drums (50 or 200 litres). A sample is sent to the FIA for approval by gas chromatography. This is the birth of a F1 fuel. It now has its official reference, similar to a genetic code. Another sample is also sent to the supplier responsible for the calibration of flow meters (based in Cambridge, England). A complete validation cycle of 3 to 4 weeks is required for each new type of fuel.

The unusual nature of the current Formula 1 power units with the electro-turbo compounded hybrid concept means that a very specific type of fuel must be used. Generating electricity from the exhaust via a device connected to the shaft of the turbocharger is not a simple undertaking since as much gas as possible at the highest possible speed must be passed though a hot turbine placed inside the exhaust gas stream. The ideal solution is to run the direct injection petrol engine like a diesel, - for instance, with a large excess of air, but at a very low fuel mix. So the fuel used must have a very fast ignition but a stable rate of combustion at a low density.

Shell is rumoured to have made a breakthrough in this area with Ferrari for 2016 and it is something which has led to a rework of the fuel pumps and injectors on the Italian V6. Indeed developments on this area between 2014 and 2015 are one of the reasons Ferrari's power unit improved so drastically.

Due to their high thermal loads, turbocharged direct injection engines are particularly susceptible to knock. This is an uncontrolled detonation after ignition and propagates at high speed in the combustion chamber. This can make the very expensive power unit into a cloud factory, perhaps with some flames. This is bad. Much of the fuel development work is focussed on minimising this knock, but the engines are designed to the limit and the chemists are struggling to keep up.

The biofuels mentioned earlier play a key part in this struggle as they burn differently (faster and at a lower temperature) and that can help reduce this, it also pushes the octane number up (we don't know the exact octane numbers of F1 fuel).

Here additives make a major difference too, you hear about fuel additives on television almost every day, Shell in particular talks about the additives in its 'V-Power' pump fuel. It may all sound like marketing nonsense but this is the difference between fuel at the supermarket pumps and the 'posh' fuels from the likes of Shell and Total.

The additives serve many purposes including detergency, anti-corrosion, anti-oxidation, reduction of the emulsion with air, friction modification plus improved combustion. They allow friction reduction in different areas and also prevent deposits and clogging in the combustion chamber and injectors.

So with the four fuel suppliers and four power units all teams get the same product right? Well actually no. The most obvious example of this is Manor in 2015, it used a late season 2014 fuel in its old spec Ferrari engines, Toro Rosso will use an old 2015 spec fuel in its 2016 car as it is using an old fuel.

Additionally it appears that the works teams get better fuel than the customers - something Adrian Newey has recently complained about, as he demanded parity in terms of the product supplied by Total in 2016. "The actual physical engine has to be the same, the ones supplied to the customer teams," Newey he told the press. "It's not just the physical hardware, it's also the petrol and the software. So the first thing you can do is to change the regulations so that customer teams have the same software and the same fuel, if they wish to, as the works team."

My take is that the fuel development in Formula 1 is out of control and a crazy amount of money is being spent on it, the fuel suppliers claim that this allows them to develop future products for production cars, but surely the engines would be more road relevant if they had to run on a variety of different fuels. My Honda often has Eneos fuel in it as I drive past a forecourt on the way to work, but if I drive to Shinjuku I tend to fill up with Shell. My car seems to perform the same.

In Super GT the rules state that the engines used can only be fuelled with whatever is available from the pump at the track, surely this would make the power unit more road relevant in F1 if the same rule was applied. It would be especially interesting at Baku, Monaco, Singapore, Sochi and Albert Park where the cars would have to run on actual pump fuel that the locals use to drive to work...

Max Yamabiko

Max Yamabiko will bring you a closer look at the technical side of F1 and motorsport in 2016, from the latest developments and solutions employed to keep you ahead of the game

 

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