Weekend Debate: Oil burning in F1 engines – a fan’s view and an engineer’s view
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Posted By: James Allen  |  23 Sep 2017   |  9:45 am GMT  |  400 comments

One of the most talked about intrigues in F1 this season has been what the engine makers are up to when they burn oil to gain performance. For most fans who like cars and F1, oil is for lubrication, not combustion. So what is going on?

This month the FIA reduced the amount of oil that can be used, to try to close off the practice, but what exactly is going on inside these engines?

One of our JA on F1 readers, Tachi, posted his explanation in the comments section, of how oil burning in F1 engines works. And in the interests of bringing the fans closer to the sport and providing insight, we sent it to an F1 engineer for a response.

Tachi wrote: “Races are ~300km, so they can burn ~3 litres of oil. They will also burn 145 litres of fuel. So burning oil is like have 2% more fuel. Distributed over a race, that is not much. Where it makes a BIG difference, is over 1 lap…

Remember that the cars have a mandatory fuel FLOW limit of 100 kg / hour. This effectively limits the output of the engine. Power gains can only be made with efficiency gains. Consider a track where a typical lap 1.5 minutes (1/40th or 0.025 hour). The fuel flow restriction limits them to 0.025*100kg = 2.5kg of fuel, or ~3.4 litres of fuel.

If the typical track is 5km long, and a driver does 18 laps over the duration of qualifying, that is 18*5 = 90km, so they can legally burn 0.9 litres of oil. Let’s just say they use half of that on each Q3 hot lap. Instead of 3.4 litres of fuel, they now have 3.8 litres of fuel for each hot lap = 11% more fuel for each special lap thanks to oil burn. Yes, that means ~11% more power.

Now you know why they can go so much faster in Q3, or selected special laps in a race (pit in, pit out, restart, etc). The strategy is where to spend the “oil fuel”. Clever, sneaky, cheating–call it what you will.

That’s what the oil burning is all about.”

Regular readers know that we have a network of F1 engineers, who are happy to help out (on condition of anonymity) with analysis on JA on F1 to help fans to understand the sport better.

So we put Tachi’s comments to one and this was his response.

Renault F1 team

F1 engineer writes: So your reader Tachi almost has the race description right except the engines do use oil as a lubricant so he can’t count all of the oil as additional power – far from it in fact.

But a small percentage could be considered as having done its job as lubrication and still find its way to the combustion chamber.

Now it isn’t fuel, so it isn’t burning at the same ‘power’ rate. However I am sure that in recent years oil development has had a consideration for also making it burn well when and if it does find itself in the combustion chamber at a convenient time in the ‘bang’ cycle.

For qualifying: it is true that within the rules you can replenish oil after qualifying in parc ferme.

So potentially if you can have a different, much faster flow of oil into that combustion chamber in qualifying than you would naturally need or get in the race, then you would benefit at a higher rate in qualifying.

Tachi has made a reasonable point in that respect. However his numbers are not correct and you cant burn at 100kg/hour on a lap because it also has a rev condition in the rules. Plus you do have to lift off at sone point around the lap!

On top of this you can’t change oil specification from qualifying to race, so it still isn’t the same as having an extra tank of equally powerful stuff as fuel that you can open the tap on in qualifying. In other words, the oil is still limited to needing to be suitably lubricating for the race.

So like these things normally are in F1, it will be a little help and everybody will aim to use the maximum they can, but it isn’t a silver bullet. It is certainly not 11 per cent power as your man has calculated).

The qualifying modes that they often talk about are simply the qualifying usage of their higher performing strategy modes: The engines are tested as being good for a certain mileage – but this is actually broken down into something that we will call “damage cycles”; like fatigue damage cycles in metals and it helps give you a number which is relevant across different conditions and track rpm/torque usage histograms (noting that every track is different).

For each engine your total allowable ‘damage’ is then kept as a running account. You will then brake it down into x laps available at strategy mode 1 which is most ‘damaging’ then y laps in mode 2, z laps in mode 3 and so on.

When you have a fast car you don’t need to use the highest modes until Q3 and ultimately if you really want to make sure you aren’t going to break down within the life of that engine you try to use them sparingly and keep the damage down or at least some in your pocket for a tricky day or a close fight in a race. [JA note: this is what we argued in the Italian GP strategy report that Mercedes did with its works and customer cars at Monza to make life difficult for the two Ferrari cars, which were starting behind Ocon and Stroll on the grid]

As Mercedes generally have a very fast car, they can maximise that approach. So when they are sure they can get to Q3 without using the higher modes then they don’t. Then when they do ‘turn it up’ it will give them a bigger step than those mid-field teams that have been using the higher end of the range in Q2.

Mercedes are particularly good at this ‘damage’ cycle system and they analyse the harmonics in the engine through its life to understand things like levels of piston slap, blow-by and wear characteristics and so on. Ferrari has also made good gains here.

So the ‘damage’ cycles left on the engine can be really well re-evaluated through the life of the engine. They can consider whether to turn it up for longer than planned at race 2 of its cycle, for example.

Renault have been playing catch up in this respect and the steps between modes are still not as big or elaborate. So Red Bull for example won’t have a few laps at that big step that Mercedes do. [JA note: Verstappen and Ricciardo confirmed this in the Singapore post qualifying FIA press conference.]

Conclusion
So there you have it, a good insight into damage cycles and oil burning, hopefully explaining what is going on. Thanks to Tachi and our F1 engineer friend for the ideas.

As a final thought, the above leads to several conclusions, but one of them is that if I were Mercedes supplying customers and my own team I would probably have a slightly more conservative set of strategies for the customer teams and would be more likely to push the overall total damage permitted on an engine in my own team’s engine either in total amount or by more extremes at the ‘peak damage’ cycles.

What do you think? Leave your comments in the section below?

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1

Sheesh – all this time I thought it Lewis a rabbit out of his Mercedes. No, I know it is not entirely oil burning but it is a help. Reminds me of some of the stories about cheating through the years, especially Sam Posey’s Dodge Challenger back in the Trans-Am days. They had acid-dipped the body to lose weight, prepped the car, passed inspection, but when the inspector stopped to chat and put an elbow on the roof, it flexed! Instant failure…

2

I don’t see anything wrong with burning oil. I had a car called Austin Allegro. I think I bought it for £300. It went well for a while and then it started burning oil. At a point when I sold it, for £20 so that I don’t have to dispose it off, it was burning like 1 litre of oil on every 5 litres of fuel. So, it was much worse than F1 cars. I told the guy “Look, it is burning a lot of oil”. “No problem” he said, and drove off. Thinking back, it could have been LH, but, can’t remember any more. Maybe that’s where all this idea started.

3

Good insight. F1 is very complicated, but James Allen try as much as he can to simplify it for us. Thanks.

4

Thanks for this article. It is rare that technical topics are discussed in such depth on websites.

5

Thanks for looking into this. I’d been meaning to find out what all the fuss was around oil burning, but hadn’t managed to do it yet. It’s one of those great pieces of ingenuity that you have to love F1 for. My gut feeling is that it’s not really much of a problem – everyone is free to do it and, other than works teams using it to get an edge on customer teams (which you have to expect, anyhow).

It’s a loophole that probably should be closed, though. If for no other reason than it flies in the face of this iteration of F1’s fuel efficiency objectives. Bloody clever, of the teams and PU suppliers, though.

6

Why can’t you then use Oil in the Fuel itself like in a Two Stroke Engine Mix ? I was always told that a bit of Oil up top is good Upper Cylinder Lubrication too !
So , can you use an Oilier Fuel in these Race Cars to get better Performance or not ?

7

Klaus : I’m not sure fuel composition rules allow the heavier oiling molecules. And anyway these would be included in the fuel counts (100 kg/race and a 100kg/hr flow).
On the opposite, the sump oil is not …

For our every day cars, although an oil-fuel mix could provide a good cylindre lubrication, I believe this would result in quite a high oil consumption and maybe cause some additional pollution.

8

@ James…You must be pleased with the responses to this topic? We have seen some really well educated and informative contributions that assist all concerned with the technical developments. Too many issues arise without any commitment to inform the fans/followers like thos that inhabit this board. As a suggestion would you consider adding an ‘ Engineers take out’ on a regular basis, bi weekly or even monthly. I’m pretty sure that you’d get a wholehearted response from not only your dedicated regulars but it would attract a wider audience that thrive on more technical detail. I will respond 100%.

9

If Mercedes can raise/lower performance as and when they desire, not just their works team but all customer teams too, they’re just toying with everyone.

Their chassis doesn’t work on twisty tracks but we’re done with those tracks. I predict Merc will unleash their furious engines and embarrass Ferrari just like they did in Monza. Expect 30 sec gaps by the end of the race in Malaysia which will demotivate Ferrari so much that they give up on this year and divert all resources to next years car.

Thank you for the article James, its great to have an engineer’s insight on what really happens behind the scenes. Hope they aren’t banned from disclosing such information in the future. Looking forward to more inside info on various other topics too.

10

James,

So when you hear reference made to the Mercedes PU being the most “efficient” you might now question this statement. One could say more correctly, the PU which best optimises the oil burn regulations.

The point of the fuel flow restriction was not to allow teams to circumvent it with oil burn. The oil burn limit should be tightened.

11
Anthony Offen-James

Surely burning 1.2 litres of oil per 100km makes these 2 stroke engines!

I grew up in the 80’s and rode loads of motorbikes that didn’t burn that much oil and they were 2 strokes

12

Hi James,

Just want to say massive thanks for this article.

Im a long time fan and avid reader however don’t often post. Its these sort of articles that are the real reason why I love your site and recommend to everyone who asks for a good go-to F1 site.

Epic article with an amazing insight delivered in a very understandable and though-provoking manner.

Keep ’em coming!

13

now that is the most intriguing post ive ever read… love it! ….. well done

14

I’m not too sure of the relevance of having a non-expert opinion at the start of the article and then having his comments systematically unpicked. Surely just getting an expert to do the article would have been a little less confusing, but a very interesting piece all the same.

15

James a fantastic article providing great insight into a clever play prevailing. Elsewhere you had mentioned that Ferrari are hard at work with Additive manufacturing -3d printing their engine parts which is expected to shave a lot of weight thereby giving additional power. What would that mean for Mercedes and F1 in general. Will other manufacturers follow suit or will it be banned like other innovations.

16

maybe this ‘damage cycle’ malarky will have to be dropped next year if the teams want to avoid penalties with only three power units.

17

I personally think cheaper doesn’t mean less engines. 3 engines for 21 races is going to be horrible to watch as I don’t think it can be done without massive penalties and even if it can it’s going to cost a lot.

18

Horrible to watch ? I would tend to agree ! In 2014, the cars had to slow down because of fuel consumption … In 2015 and 16, it was because of the tyres … This year, I suspect that the engines are so efficient that they canno’t withstand the full fuel flow for long …

So, 3 engines for 21 races ? Reliability will be the key. A solution could then be to reduced the allowable fuel flow.

… Unless you consider than the engine is part of the game and also, that overtaking difficulties are the real issue !

19

Great insight into the tech side.
However,the sooner these PU are replaced by something less complicated,expensive and manufacturers control the better.

20

Great article James, so in reality the Mercs are cheating legally? Now joined by Ferrari.

James, are these strategy modes the reason why HAM’s engine died at last years Malaysian GP, using strat mode 1 too often…explains a lot of their recent dominance and making the sport look bad from a spectators point of view.

21

It was probably because Hamilton’s engines were Frankenstein engines from Spa on.

22

Can we have some bhp figures.?

24

That’s 6 x 7? To know what the answer is first know the question.

The question is what is that oil Mercedes use to make them take engines early to get around the or go through 2017 rules. They can now use more than 0.9 until the end.

Why is 0.3L that important? We will find out next Sunday if it even is but they sure think so.

25

I am happy to see this issue addressed from an engineering point of view. There has been all sorts of urban legends circulating about this issue.

26

We wouldn’t be having this discussion if we still had V10s!

27

Knight, if they had thought of it in the V10 days, they would have done it.

28

I’d say that the oil burning issue is more due to fuel limitations rather than the type of engine …

29

Are f1 engine oils 99% similar to our oils like the fuel they use?

30

the fuel used in f1 cars is fairly similar to ordinary petrol, albeit with a far more tightly controlled mix. formula one fuel can only contain compounds that are found in commercial gasoline, in contrast to alcohol-based fuels used in american open-wheel racing.

http://www.lubricants.total.com/motorsports/formula1.html

31

In the US the fuel for all teams comes from the same manufacturer.

The oil is not that tightly controlled in F1 unless I read something wrong.

32

11% more power is in the realms of Fantasy, but even if it delivers a more realistic 2-3% increase that equates to 20-30bhp which is a massive edge in F1 terms!

33

Yeah I think 11% is theory that may have been close in 2014 but only 1% is huge. That’s almost half a lap in an entire race.

34

I have no problem with any team trying anything to gain performance, within, or on the edge of the rules. Every year we see new innovation and rule-bending; I find it fascinating and quite frankly, it is a big part of the attraction of Formula-1 for many of us. Imagine a grid of cloned cars with nothing different bar their paint schemes; quite dull I think.

35

That would be terrible… the only difference then, would be the drivers’ skill!
Seeing Ricciardo win every race while Lewis circulated at the back of the pack and Max and Kimi smacked into each other at every race, would soon get very boring. 🙂

36

Axel, do spec series always bring good racing? Not in my experience, you often get one team dominating as well, good idea in theory, but tends not to pan out in practice.

37

No but if he in fact really is that good I want to see it.

38

something missed out on though was the fuel and oil supplier ( lets for arguments sake say Petronas) having a oil with a quantity of its makeup totally useless as a lubricant but having no detrimental affect on its ability to lubricate moving parts but when mixed with a certain fuel blend having a catalytic effect on the burn in the combustion chamber, I would probably presume making the wave face of the combustion cycle more predictable allowing more boost or advance to be run on the engine,lets also not forget that with fuel flow restricted then its also a possibility that a little bit of oil blow by is measured in for crown temp control, as for managing the damage cycle it sounds pretty much what goes on on aircraft parts with HUMS systems ( health and usage management) in live time so the pit sees lifeing information about the engine and can then give advice to the driver on engine modes

39

Exactly! Fuel and oil from same supplier solves this especially for customer teams.

The politics of actually doing that I see being very hard. Maybe to define what can and and what cannot be in the oil and petrol and enforcing it with an MS GC machine might work. Even something like that me be a hard deal to strike.

40

ross brawn has an idea of the mercedes advantage. if it was illegal, he’d have been onto the stewards to stop them at once. it’s just all talk..

41

A great article, but very depressing…

Ross Brawn has a huge job on his hands.

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