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f1 fuel racing

Tech Draft: The need to keep Formula 1 fuel cool

f1 fuel racing

There was something unusual that happened on both the Miami and Spanish Grand Prix weekends that I don’t think was purely coincidental and has been on my mind ever since

So I thought I’d put my thoughts about it down in words as a catharsis to help me resolve in some way what it’s all about.

Recently at the Miami Grand Prix Aston Martin took the decision at their own discretion not to send both cars to the grid so that they could start the race from the pitlane instead.

There’s nothing unusual about cars starting from pitlane, it happens all the time, doesn’t it?

There’s a whole list of reasons why cars start from pit lane ranging from mechanical issues through to the enforcement of penalties, but for Aston Martin in Miami it happened for a very unusual reason: they weren’t sure that their fuel was warm enough.

Say, what?

2022 FIA Formula 1 Technical Regulation 6.4.2

Technical Regulation 6.4.2 states that. “No fuel intended for immediate use in a car may be more than ten degrees centigrade below ambient temperature. When assessing compliance, the ambient temperature will be that recorded by the FIA appointed weather service provider one hour before any practice session or two hours before the race.

“This information will also be displayed on the timing monitors. The temperature of fuel intended for use in a car must be measured via an FIA approved and sealed sensor.”

Regulation 6.4.2 background and relevance to today

The origins of this regulation goes back a few decades to the days when there was no refuelling and the cars were limited to something like a 200-220 Litre capacity, I can’t quite remember the exact amount.

Some teams would supercool, or essentially freeze, their fuel as it was loaded into the fuel cell(s). As the relationship between volume and temperature is an inverse function, cooling the fuel allows for a greater mass of fuel to be loaded into the cell(s) set volume.

However, in the modern age of ultra-efficient F1 cars carrying under half the fuel in comparison to the days gone by, and very accurate direct combustion chamber injection as opposed to inlet trumpet or plenum delivery, even a minor lowering in temperature results in more oxygen in the chamber and a more energetic detonation consequently.

However, I also understand that there is another benefit in that cooler fuel has a greater capacity to absorb heat from the inlet charge, which marginally increases the amount of air heading for the cylinder, once again creating a more energetic burn.

Obviously, starting the cars from pit lane gave Aston Martin the opportunity to buy a bit more time so that they could ensure that their fuel temperature(s) were legal.

BARCELONA, SPAIN - MAY 22: Max Verstappen of the Netherlands and Oracle Red Bull Racing prepares to drive on the grid during the F1 Grand Prix of Spain at Circuit de Barcelona-Catalunya on May 22, 2022 in Barcelona, Spain. (Photo by Mark Thompson/Getty Images)

With Red Bull experiencing a similar issue in Spain, is there a bigger issue to consider?

There could be a multitude of reasons why this occurred, and in isolation it probably isn’t such a big deal because I haven’t heard about this happening very much at all in recent years.

Nevertheless, when both Red Bulls arrived on the grid to take their positions in Spain much later than anyone else because of the same reason I started to wonder if there was a common thread happening.

After plenty of contemplation about this I can only rationalise that the whole fuel temperature issue is a result of F1’s homologation freeze on internal combustion engine elements of the power units. The freeze has happened at a time when ICE performance across the suppliers has converged to a level that the practice of running the fuel temperature as low as the teams dare to without subceeding the temperature limit provides a measurable performance advantage.

Keep an eye out for this to keep happening

We all know that the regulative guardians of contemporary F1 don’t want the power unit to be the competitive differentiator that it once was and that their wishes for the sport moving forward is that of a more parity-based model, and many of us find that to be a shame and against the intentions on which the sport was founded, but there is also the very important aspect of safety to consider.

After all, the less handling of fuel that occurs in the garage, particularly when pumping it through equipment such as refrigerated machinery, the more risk analysis boxes go green.

It is no coincidence that the ambient temperatures in both Florida, and Spain on the weekends that these incidents occurred was quite high, more than 30°C, which is interesting and something to keep an eye on this weekend in Azerbaijan with forecasts for Baku predicting it to be hot again, in the high 20’s to low 30’s, as it usually is.

In my opinion, because the technical regulative model that Liberty and the FIA seem to be happy with moving forwards is based on the concept of performance convergence and parity, gains such as those realised through ensuring that fuel is delivered into the combustion chamber at the lowest possible temperature allowed, are certainly worth pursuing.

For that reason, particularly on Formula 1 race weekends with high ambient temperatures, I expect to see this issue reoccurring.