Why F1 should keep its fuel limit

Formula 1 achieved a quite incredible feat last year, one that was disgracefully overlooked in most quarters, sometimes by those purporting to enjoy the technology in grand prix racing.

Last year, every car had to complete a grand prix distance, from lights out to chequered flag, on just 100kg of fuel. Staggeringly, it wasn't long before some were actually short-fuelling in order to save weight, without paying much of a performance penalty.

Think about that for moment. Really think about it. That's a reduction of about one-third of the fuel in one leap. Truly astonishing.

There have been suggestions that both the 100kg fuel limit and the 100kg/h peak fuel-flow limit should be removed from the regulations as part of this agenda for more exciting cars in 2017.

Fine, remove the fuel-flow limit. In fact, that is a must. But to eliminate the fuel limit would be a mistake. It would rob F1 of one of its greatest achievements not just in recent years, but, at the risk of drifting into hyperbole, ever!

McLaren's MP4/3 from 1987 could carry 195 kilograms of fuel © LAT

Fuel has a certain energy value. The aim of an engine is to unlock as much of that energy as possible. Efficiency is nothing more than the percentage of the energy that you are able to put to work, and in the case of the internal combustion engine, traditionally this has not been a spectacularly high number.

Yet still F1 took this one-third reduction in fuel for a grand prix distance in its stride. There was no limping to the finish, no running out of fuel. Just grand prix cars lapping quickly and racing.

And remember, while there is still some fuel-saving, the same thing happened with the last generation of 2.4-litre V8 atmospheric engines. It's just that it wasn't talked about as much.

The equation is very simple. Fuel has a performance cost that is proportional to its weight. 10kg of fuel can add around 0.3-0.4s per lap (depending on the circuit configuration) to your laptime.

So if you can carry less fuel, that is free laptime. If this number outweighs the loss caused by fuel-saving measures, you are quids in. There is always this compromise, there's nothing new. It's just that it has been talked about more and more in recent years.

And there could be more gains to come. Speaking after the unveiling of the new Mercedes F1 car, the managing director of Mercedes AMG High Performance Powertrains, Andy Cowell, pointed out just how much potential gain there is still to be made with the efficiency of these engines.

"The maximum power output if we get 100 per cent thermal efficiency is 1200KW plus 115kW [from the ERS]," he said.

Andy Cowell says there is still a lot of unlocked potential in the Mercedes engine © LAT

The second law of thermodynamics prevents absolute efficiency. But translate those KW figures into the easier-to-picture horsepower, and it reveals that such an engine (without ERS) would put out just over 1600bhp. So there is still room for improvement with ongoing incremental efficiency gains.

But the instantaneous fuel-flow limit that caps the rate of fuel being fed into the engine at 100kg/hour (think of it as a speed of fuel feed, rather than an allowance), is something that can be axed.

This rule exists for a very valid reason. There is no cap on the turbo-boost in the technical regulations, so this is the only thing that keeps the maximum engine power in check. So it would have to go if you wanted to increase the horsepower of these engines.

It has been said that this makes the 100kg-per-race target achievable, but that's not the case. The limit would have to be respected no matter what the peak power is, so it's not relevant in this instance.

But there were legitimate safety concerns. After all, the most effective way to take a straight would be to put down as much power as you could possibly transfer to the track and get up to your terminal velocity as quickly as you can, then coast.

So you might choose to have massively powerful engines, booting out a short, sharp burst to get the cars up to speed, then leaned back massively.

Refuelling hasn't been allowed in Formula 1 since 2009 © LAT

The safety concern comes in were you to have significantly different peak-power figures from car to car (i.e. a car with twice the power booting it while right behind a less potent one).

This scenario is not as concerning as it initially sounds. But if you removed the fuel-flow limit, it would be a surprise if the variations were that dramatic. So eliminate that regulation, while maintaining a fuel limit, and you have a workable framework.

That's just a low-resolution version of the rules set, but using those two key factors, it should be possible to frame a rule that satisfies all.

Critics who come back with the argument that the amount of fuel saved is so small as to be irrelevant are missing the point - in some cases, probably willfully.

Yes, the fuel not burned during races over a season wouldn't get you halfway across the Atlantic on a commercial airliner. But that's not the point and it never was.

But it is a clear statement of intent, an expression of potential to be part of the solution rather than part of the problem.

You can argue it's nothing more than window-dressing (after all, how much fuel is burned carrying freight, team personnel and AUTOSPORT journalists to all the races?) but its value is way beyond that.

This is where there is scope for technology transfer. Not the simple transplanting of a bit of kit from an F1 car to a road car, but for the exchange of ideas and techniques that can have a tangible influence on road-car efficiency.

It's not going to change the world but, as knowledge always does, it has a value, particularly to the engine manufacturers that lobbied for such a change.

Is a return to 1000bhp engines worth sacrificing efficiency over? © LAT

Even more importantly for F1, it has genuine commercial value. Many sponsors won't touch grand prix racing with a bargepole. While there are many reasons why not, one of them is environmental concerns.

Big companies now take corporate social responsibility very seriously. And while it's not the case that simply having some 'green' credentials means the money flows in, without it the pool of available partners could shrink to nothing.

But forget the financial side; it's the technology that impresses me.

It's not always about more power, more grip, more whatever. Efficiency has always been central to the effectiveness of any engineered system.

And given our global situation, with climate change (and yes, in particular I'm referring to anthropogenic climate change) efficient use of energy with technology is at the heart of everything we must do to ensure our survival.

But most importantly, completing grand prix distances at racing speeds using just 100kg of fuel is simply a majestic tribute to the better part of F1.

I certainly wouldn't swap that for a bit of noise.

As Williams chief technical officer Pat Symonds put it, "it's not of interest...noise is wasted energy".

Quite...