As we head into the potentially hot Malaysian Grand Prix this weekend, the big question is Red Bull’s approach to the issue of fuel flow and the sensor the FIA uses to measure the rate at which the cars use fuel. Having faced a disqualification for Daniel Ricciardo in Australia and an appeal not set until the Chinese Grand Prix, the team is forced to deal with a sensor they believe is unreliable. This notion of a drifting or unreliable sensor could mean the difference between winning and losing according to team boss Christian Horner.

“We have got to find a better way – especially when the margins are so fine and the knock-on in performance is so significant,” Horner told AUTOSPORT’s Mr. Noble..

“Depending on the calibration of your sensor, it will determine your competitiveness, which is completely wrong.

“Teams will end up buying hundreds of sensors, as some manufacturers already have, to try to pick the best.

“It ends up like the tricks in go-karting, where you go through carburettors to try to find the best ones. I don’t think that is an acceptable way of moving forward.”

Horner reckons the performance gain could be large and there must be a better way to read the fuel-flow rate in a sport such as Formula 1:

“F1 costs millions and millions of pounds. There needs to be a better form of measurement than what we currently have.”

“On an aircraft they have three sensors and they believe the mean between those sensors,” he said.

“If one shows a drift then the other two count. I think it is very immature technology in F1 and we are trying to rely on a sensor that has proved to be problematic.”

Horner says that this weekend’s race will be approached in conversation with the FIA in order to use a sensor that works and provides reliable data. Horner says that it is most likely not unique to Red Bull either and that other teams are experiencing the same issue.

What is most interesting is AUTOSPORT’s conversation with Horner about how they are approaching the appeal on April 14. According to the article, Red Bull does not view the technical directives from the FIA as holding any regulatory value. They cite the secret Mercedes test decision as proof:

“Technical directives are not of regulatory value.

“They are the opinion of the technical delegate – as was made clear in the Pirelli case [the Mercedes secret test], which clearly stated that opinions of Charlie are not regulatory.

“It [them being opinions] is even stated on the bottom of the directives now, that these do not have a regulatory value.

“Our position is as it was in the race: that we believe, and we believe we will be able to demonstrate in the court of appeal, that we fully complied with the technical regulations – 5.1.4 – to be explicitly clear.”

Arguing that the technical directives are simply opinion of the technical delegate will be a very interesting case and could prompt some serious changes in the way the FIA goes about regulating the sport including on-event stewarding and directives.

It’s difficult to know all of the details that transpired during the Australian Grand Prix and winter testing regarding the fuel flow sensor but it would be a bitter pill to swallow if your car was competitive or not competitive based on a drifting sensor. It would also be a bit of a slippery slope to suggest that FIA regulations do not include technical delegate opinion and therefore can be heeded or not depending on a team’s position. So what does Red Bull do until the appeal? Horner told AUTOSPORT:

“So when you are faced with that dilemma of having a sensor that you believe to be erroneous, and a fuel rail that you believe to be entirely reliable, and you are racing for position with an engine already down on power compared to your opponents, what do you do?

“Do you believe unreliable information being given?

“We are absolutely convinced that we abided completely by the technical regulations.”

What do you think? Are the technical directives simply opinion and not of regulatory value? Would you trust the fuel rail and ignore the sensor?

An F1 fan since 1972, NC has spent over 25 years in the technology industry focusing on technology integration, AV systems integration, digital media strategies, technology planning, consulting, speaking, presenting, sales, content strategy, marketing and brand building.
  • nofahz

    Horner’s caught cheating PR reminds me of the old adage: tragedy when it happens to me, comedy when it happens to you. But if Mercedes can get away with an illegal tire test I suppose any defense is tenable.

    • Schmorbraten

      +++ Off topic but important +++

      Come on guys, let’s get a round of donations going. I too am guilty of being too lazy until now to get round to donate something to F1B. We’re a growing community, server load increases, in other words the server load gets more expensive, and we all participate in a lot of great stuff that F1B offers here.

      S5, $50, whatever you’ve got, it’ll be better than nothing and it’ll easily add up to a lot altogether so this site can keep going and growing.

      If you’ve already got a Paypal account, it’s REALLY easy and it doesn’t even take a minute!

      • Thank you so much for your help, mate. The traffic has forced us onto a dedicated server and doubled our costs for the service. Over the next 24 to 48 hours the propagation should occur and help the load times plus new software that’s coming.

        As a non-monetized site, the move to a dedicated server does make this a difficult monthly expense. Your help is truly appreciated and needed. We have tried to create a safe harbor for fans to come and have intelligent, fun and opinion-filled discussions and that is a testament to all of you who engage with decorum and civility. I think you have all built something very unique in the world of motor sport and I couldn’t be more honored to provide the infrastructure and site that you’ve chosen to break the mold of online trolls and flamers and have fun with the sport you love (regardless of engine sound). Thanks to all of you for making F1B what it is.

        • Rapierman

          I’ve made my contribution. It’s small, but it’ll have to do.

  • Ground Effects

    Perhaps this answers the question raised in the podcast as to why Red Bull was not black flagged during the race… the issue was instead taken to the stewards after the race. Hard to believe there has not been an independent test on a representative sample of these flow meters to determine their quality and perhaps Red Bull shows up to hearing with such a test on their fuel injectors to attempt to demonstrate that they did not flow more than 100Kg/hr or 100Kg for the race.

  • Bill

    The FIA was wrong to allow Mercedes test last year and Mercedes got away with murder.

    The penalty Mercedes got was a complete a total joke.

    But that does not mean that RedBull should be allowed to cheat and get away with it. Shame on the FIA for the Mercedes scandal but even bigger shame on the FIA if they allow RedBull to get away with this.

    RedBulls sensor was off but they were given an offset value that would account for the error and RedBull refused to even use the offset value. Instead they went their own direction and did what they wanted to do instead. They were warned multiple time by the FIA during practice and at lap 5 of the race, RedBull ignored the FIA and it was made clear to all the teams that this matter of the fuel flow sensors would be serious if a team choose to ignore the fuel flow.

    RedBull upon losing the appeal should receive a revised penalty that includes at least a one race ban.

    RedBull has gotten away with a lot of rules breaking like their flexing front wing that when in use clearly was not within the rules but they some how built it to pass the weight test. Just because it passed the weight test does not mean the wing was legal when there are video after video of the same wing that passes the weight test no flexing in violation of the rules.

    In my opinion the best thing that can happen to Formula One is for RedBull to take their ball and go home. They have a rich owner who out spends everyone else and now they have new regulations and all their money has been evened out by a single fuel flow sensor and they are upset. I guess I would be upset if I out spend all the other teams only to have a fuel flow sensor balance out the performance of the cars. These sensors are calibrated to a very small error and that little bit of error would be pretty much undetectable on the race track and RedBull knows it.

    • Tom

      Repeating this post doesn’t make it any more true. You do understand the key differences between the Red Bull and the Mercedes case? As in, that they’re the complete opposite?

      Mercedes asked the technical director BEFORE they agreed to a test that Pirelli needed and he said that it was ok as long as Pirelli conducted the test.
      Despite this, Mercedes was still given a punishment, so they didn’t get away with anything, let alone murder.

      Red Bull on the other hand was approached by the FIA and asked to change their fuel flow settings on Saturday. Yet they’ve chosen not to protest or to consult, but simply to silently ignore the order. They did so again and again until the race was over at which point Ricciardo was disqualified. Only then did they loudly start to protest, AFTER it was all said and done.

      Horner’s point regarding Mercedes is that despite the word of the technical director, they still got punished, so by the same token, he wants to go Unpunished.
      Only that I think this isn’t necessarily the same token at all. But the courts will sort it out, I’m sure.

  • wchrisg

    From what I understand please correct me:
    The teams don’t go to Gill and get a bucket of sensors they are given the sensor which they can swap for a new one and which the FIA gets tested Independently.
    The FIA specification makes the sensor error to benefit the team.
    The sensor is tested and calibrated by a third party, not Gill and not the FIA.
    The sensors are not immature they have been used by the ACO since 2011
    A Technical Directive is not opinion it’s an explanation of how the Technical regulation are being interpreted by the regulating authority is complying with the regulating authority specified in the regulations.
    All the others teams comply with the directive(s)
    Red Bull complies with other technical directives.

    • Tom

      That’s basically correct, only the teams do buy and own the Gill sensors. They do however have to send it to a third party for calibration.

      Apparently, Red Bull came to Australia with only four sensors, other teams had as much as 12. Still, I’m sure that Red Bull could have gotten another one, had they demanded one. They knew on Saturday all the facts. They knew which sensor they were supposed to run and how the FIA wanted their fuel flow to be adjusted and they knew that they were going to ignore it. Why not protest then? Why not argue their case with the FIA? Why not try to convince them BEFORE the race that their sensor is crap and that they should be allowed to use their backup system, alternatively, why not plea for a new sensor? If you wanted everybody to know that you run your car legally, that would have been the way to go.
      Knowing all this, yet keeping it to yourself until after the race doesn’t really help Red Bull make their case.

      • UAN

        Tom, I really appreciate your contributions on this issues, you’ve been a big assist in unravelling the technical issues involved.

        I would disagree with your assessment though on how to effectively address/argue their case with the FIA. The first race is the ideal time to do this, especially after their less than stellar pre-season testing.

        As in many things (outside of F1), for an issue to get a full hearing and be fully resolved takes a test case. Trying to convince the FIA before the race was pointless per the TD issued. The FIA was under no pressure to legitimately look at the issue.

        In terms of “keeping it to yourself”, well that’s not really correct. It was clear to the FIA by lap 5 that Red Bull chose to go with their readings over the Gill sensors. The FIA was fully aware of what was going on, and that’s all that’s important. It’s not for RBR to let the media, fans or their competitors know their strategic decisions. And it may be that they also weighed the decision based on how the opening part of the race panned out. If RIC qualified lower, or the other Merc powered cars blew past him early on, they probably would have chosen to just use the readings of the sensor.

        Whether you agree with it or not, RBR does have a strong case per the Technical Regulations. It may be a loop hole, but, well, loop holes have been exploited for years by many teams in F1. I’d say not exploiting a loop hole at this level would be negligence.

        Regardless of the outcome of the appeal, and all semantics aside, it is more than likely RBR was within the 100kg/hr regulations (or they wouldn’t bother to appeal). And the decision RBR made to challenge the TD is fully with the process and procedures of how F1 works. It sucks from a fans perspective, but then so do double points and DRS.

        But it’s better to do it at the first race when they had little to lose, with no real expectations of points to begin with, to challenge this. And one of the reasons RBR are the 4x defending WCC is that they push everything to the absolutely limit. That’s what F1 is about. There’s no shame on their part that it’s not acceptable to them that they can’t run at 100kg/hr and are taking steps to change that status quo. In fact, it’s good they are tackling this early on. There have been instances where teams sit on breaches of regulations that they know of with their competitor (for instance the wheel incident in 1976 involving James Hunt).

        • Tom

          First of all, I doubt that Red Bull’s objective is to fight the fight against vague rules or any such thing. This is F1 and these people necessarily have to be cynical or they wouldn’t be there, let alone successful.

          So this is only about Red Bull. And in that case, I still don’t see why they kept silent until the race. You say it’s unlikely that anything would have been different, but I don’t think so. At the very least they could have used a different fuel sensor. They must have had at least one spare sensor that so far wasn’t used that weekend. The only reason not to do that is when you know that you probably won’t be able to run the car legally using any fuel sensor. It would appear as if Red Bull willingly used that particular fuel sensor, since it did apparently provide odd readings during FP1, so they could make a better argument AFTER the race for why not to trust it. Had they used a new sensor, they couldn’t have used that excuse.

          But even if the FIA wouldn’t have given in at all, Red Bull still could have done the same thing and refused to listen to them, just the way they did, only then would they have a better case come the lawsuit.

          And there we come to the core of the problem. For some reason, Red Bull seems to struggle with the data from the fuel sensor when others don’t. That doesn’t make a convincing case at all.

          As for Technical Directives/Technical Regulations, even if it’s true that Technical Directives have no authoritative power, then they still must have an informed legal argument on which it is grounded, otherwise they’d be pointless. And even ignoring the Technical Directives, the only method of measuring fuel flow that is sanctioned by the Technical Regulations is via the homologated fuel flow sensor.

          Not to mention that it should be rather difficult to prove their point when the only independent sensor is the Gill sensor they don’t want to use. Everything else is simply way too easy to manipulate, which is exactly why the fuel flow meter was introduced.

          After pondering about all of this for a bit, I figured that Red Bull might possibly be after another loophole, only they don’t openly argue that way yet. And that is that there isn’t any defined time frame in the regulations during which the fuel flow must not exceed 100kg/h. I guess that was done in order to give the FIA a little learning space until they settle with a suitable timeframe…and as we know, they didn’t hit it immediately, first they went with 0.1s, then they settled for 0.2s.
          But, Red Bull might argue that nowhere in the rules there is a time frame given other than an hour in the limit oh 100kg/h itself. If that’s what their real objective was and they would be successful, this would effectively kill the 100kg/h limit on fuel flow.

          • jeff

            Although the Gil sensor is the sole homologated device (TD 5.10.3), there’s no regulation excluding alternate measurement means, and no verbiage linking the fuel flow limit regulation with the homologated sensor in the Reg’s. That’s where FIA screwed up; it’s a logically-inferred conclusion that 5.10.3 be the device used for enforcing 5.1.4, but not an explicit one.

            Interesting theory re; another possible RBR argument. There’s no regulation corresponding to either the meter’s sample rate, nor any other time rate-based measurement lingo other than the 100kg/hr, so if RBR hasn’t thought of that argument, you’ve just given them fodder :D

          • UAN

            “Red Bull seems to struggle with the data from the fuel sensor when others don’t.”

            That’s not quite accurate. Mercedes had issues and on 3/21 on Sky’s F1 Mid Week Show, Graeme Lowdon basically said they had the same issue.

            We don’t know what issues other teams are having. We only know that RB is the only team making it an issue. In fact, they may actually have less of a problem than other teams. And if RB or Ferrari or McLaren catch up quickly to Mercedes (look at FP2 in Malaysia), Merc may find the option of turning down their fuel flow is more problematic than in AUS.

            I’m reminded a bit of the engine mapping and off throttle blown exhaust (hot, iirc) issue back in 2011. I remember many teams thinking that was what was giving RBR it’s advantage over the field. In Valencia, the engine maps were changed for Silverstone. RBR wasn’t happy and I remember Whitmarsh looking smug about the change. Then in Silverstone, turns out McLaren suffered the most of the top teams, with RB only suffering a bit.

            Teams do what teams do in their own best interest or when it’s perceived to be not in the interest of a rival. Fair play to all.

            Re getting a new sensor. Don’t know how easy that would have been – my understanding is RB had 4 and it’s not like they could just pop over to Ferrari next door in the pit to borrow one. And then what are they going to do, just slot it in during FP3 and see how it goes and hope it works? Really?

          • UAN

            As a follow up to the fuel flow sensor and RB being the only team to struggle with it, I was just listening to the beginning of FP2 on Sky, and Martin Brundle said he was told there was at least one car in AUS that had no sensor at all because it was faulty. Wow. Where’s the transparency from the FIA on that?

            So no sensor for one car and at least 3 other cars we know of showing a difference between their fuel rails and the sensors? Yup. Pinnacle of motorsports and darn RB for saying that’s not acceptable to them.

          • UAN

            One final bit of info – the sensors apparently cost $16k each (not sure if that’s euros or USD) and RBR have 4 in Malaysia – it appears Mercedes bought a whole bunch. After FP1, Brundle said Horner told them that 2 of the 4 may have problems.

            It’s not as straight forward as it seems.

  • Hear we go again…
    Someone give RB a pacifier, there is allot of difference between…
    Flow not to exceed 100kg/h & not to use more than 100kg/h even RB should understand that

  • phonebem

    I’ve been following this for the past (nearly) two weeks and decided to finally take a look at some empirical data for the sensors in question. Having a 16-year aerospace equipment calibration background, the argument over the adequacy of the flow meter in question really piqued my interest; the following is what I’ve been able to determine… (warning this is going to be pretty math-intensive)

    First according to the published specifications for the Gill sensors in question ( the worst-case accuracy of the sensors, to be considered functional, is ±0.25% of indicated flow rate, it must be noted that this is a rather tight tolerance for a flow meter that wouldn’t be considered a calibration standard who’s size and associated accessories would preclude its use in this application. This equates to an acceptable error of ±0.25 kg/h @ 100 kg/h (unless otherwise stated all calculations will be stated @100kg/h), this equates to ±1.66kg/minute or ±0.0277 kg/second this equates to an uncertainty of 27.77 grams of fuel per second passing through the flow meter to the engine.

    To put the ±27.77g/s into perspective, given the allowable fuel density of between 720 and 755 kg/m­­³ @ 15°C ( we can calculate the maximum allowable uncertainty of the fuel volume to be between 36.78ml/s and 38.57 ml/s depending on the specific gravity of the fuel the team is using. Keep in mind this error in fuel amount is spread over 6 cylinders each with approximately 83 ignitions/s (@15,000 rpm). This leads to an error per cylinder of between 0.44 and 0.47ml or about 335mg of fuel per ignition.

    I’m betting this uncertainty, albeit a worst case scenario, would be more than enough to have a drastic effect on the tuning of an engine. Bear in mind however the sensors would be verified and most likely “cherry picked” to ensure they would be the ±0.1% ones and an offset would be provided to the teams to account for the expected error of the sensors.

    This is about as far as I can go without knowing the specific boost levels, fuel pressures, and fuel mapping the teams use; not to mention this is where I run-out of experience and knowledge. Perhaps somebody with more specific knowledge of engine tuning could run the numbers on how this would change A/F ratios based on expected intake air densities and engine tuning principals and give us some expected HP variances based on my figures…

    • Tom

      I don’t know what you’ve done there, but I cannot see where you’re numbers come from…let me try and then maybe you can tell me where we parted ways:

      So the sensors are accurate to the degree of 0.25%

      0.25% of 100kg is as you rightly point out 0.25kg, which is the same as 250g. Now, one hour has 3600 seconds, so the allowed variation per second would be:

      These 69.4mg are a far cry off of your 27.7g.

      From there, obviously all your other numbers are bound to be wrong.

      But even using your numbers, there are more errors to come.
      At 15000 rpm you have 250 rotations per second. In a four stroke engine, it takes two rotations for every cylinder to fire once. So we have 125 double rotations which we then have to divide by 6 which is 20.83 or roughly 21 ignitions per cylinder per second. You seem to have doubled the 250 rps instead of halved them.

      So when we divide the 69.4mg by the 20.83 ignitions, we arrive at 3.33mg/ignition which is two orders of magnitude from your 335mg.

      BTW, you’d get a worst case scenario at 10500 rpm, not 15000 rpm, because there we have the same limit on fuel flow, albeit less rotations and therefore less ignitions, so the amount of fuel per ignition is higher. If you do the math you get to 4.75mg instead of 3.33mg.

      • Tom

        LOL, there I go trying to correct people and then I go and embarrass myself. Luckily, I found my error right after posting my comment…too bad I can’t edit it, so it’ll remain there for everyone to see ;)

        In fact, the error of the sensor is even MUCH smaller than I calculated, as I mixed up my operators. I guess I could tell you that this was due to me trying to reconstruct Phonebem’s numbers, but that would at best be half the truth…no, I mixed it up myself.

        Once you get to the 125 double rotations, I divided by 6 when I should have MULTIPLIED by 6, as all 6 cylinders fire during each double rotation.

        There are 125 ignitions per cylinder per second and therefore a total of 750 ignitions per second. So we have to divide the 69.4mg by 750 ignitions instead of 20.83 which gives us 0.0925mg, or 92.5µg. So the difference to the 335mg in the original post has now grown to (considerably) more than three orders of magnitude.

      • Phonebem

        Yeah, well that’s embarrassing, I REALLY screwed those up…(possibly so much I broke the site, hence the maintenance…) I really don’t know how I failed to notice that… Maybe I should have just done it all on paper instead of trying to type it…
        At any rate, you followed theath I was intending to lead people down which was to try to illustrate how small the allowable variance is. Based on your (corrected) error calculation of 92.5ug I’m betting any tolerance in the temperature measurement (+/- 0.5 C would be tight) would likely account for a greater error in the fuel mapping than that of that of the flow meter…

        Another thing to consider, according to the spec sheet the maximum operating temperature of these sensors is supposed to be 85C/185F. It is well known that RBR may have heat issues. This could be a factor depending on where they’ve chosen to mount the flow meter. This is just speculation since it’s nearly impossible for us to know what potential heat sources may be co-located with the sensor. It would however potentially explain why only RBR are having this problem.

        • I think you’re right that if the fuel meter performs according to its spec sheet, it should be very accurate, probably more so than anything the team does.

          If the team runs it outside of its specified operational window, i.e. too hot, that alone should be grounds for disqualification IMHO, as it could influence the readings both ways and it could start a sport of trying to get the sensor to perform favorably for the team.

          Lastly, it has been leaked that three teams altered the sensor due to packaging issues. I wouldn’t be surprised if Red Bull was among them…

          PS: Sorry for the late reply, but I had issues after the site was moved

  • jeff

    Were several posts and more resultant responses dropped off the site in an update? I recall some “Vettel says sh*t” post at the top, and many interesting discussions that are no are gone.

    Phonebem, my lost post questioned how you got that 1.66kg/min figure, but as Tom’s already mentioned it, may I ask you (and Tom) how individual injector flow is relevant if solving for power advantage/disadvantage from the fuel sensors’ rate variations? Isn’t total fuel flow all that matters since we’re looking for total power potential within that +/- .25% deviation? Shouldn’t one be looking at the almost +/-65.5 mg/sec, if that’s the rate one’s interested in?

    If i’m misunderstanding, apologies. If not, perhaps you can further assist; a week ago I tried solving for potential hp gains/losses due to meter- variation in a post and gave up; too many unknown variables and my shoddy math skills/conversion errors mucking up figures. :)

    As you’ve mentioned, converting the fuel into approximate hp is extremely difficult w/o fuel content (using oxygenates?), ambient air density/temp, and thermal/combustion efficiency ie; compression, how far from stoichiometric ideals the teams are running (I’d bet pretty rich), how they’re playing w/ valve overlap, turbo/intercooler adiabatic efficiency and so on. Simply put, air and fuel quality and A/F ratio figures are king, and we know none of them.

    With your post, my curiosity’s piqued again and had hoped with a few base assumptions I could find some number to satisy it:

    -The teams’ fuels are similar to road gas. Energy Density therefore ≈ 46 MJ/kg
    -Engine manufacturers met their 40% thermal efficiency ICE goals
    -The fuel sensors are working within their tolerance window.

    Using the above only, I got a 17 hp swing either way with the meters’ .25% variance at 100kg/hr. Something’s off here involving rate, but I can’t figure it out; any pointers would be appreciated. I’m getting figures that mesh w/ theoretical ideals (1700 horsepower potential/680hp at 40% TE ignoring aforementioned VE tables and pumping losses) but I’m missing how to implement the time-based variables.

    As far as tuning, it’s A/F ratio manipulation via fuel flow, not air ingestion. They aim for max volume, w/ sufficient velocity for the given rpm, and introduce fuel appropriate for that figure and charge temperature. From your last paragraph I think you were assuming the opposite (although w/ the big compressor and nifty artificial E-turbine, these F1 engineers likely have more influence over air intake than most).

  • jeff

    “almost 69.5mg/sec” not 65.5 in the 2nd paragraph

  • Phonebem

    I guess the point I was trying (and failing) to make was how small an error the flow meter allowed based on the potential uncertainty in energy delivery to the engine. Also there was so much rampant speculation over the “accuracy of the sensors” that I wanted to use published data to (fail to) illustrate that. I’m betting that any tolerance in the temperature measurement of the intake air charge would account for as much potential power loss as the tolerance of the fuel sensor. I’m speculating here, but it sounds like you would be much better qualified to determine that.

  • Phonebem

    Jeff and Tom,
    I wanted to thank both of you for not being too harsh in pointing-out my ridiculous errors. I appreciate that you looked at what the point I was trying to make instead of just ridiculing my simple oversights.
    Thank you both.

    • Very late response to this, sorry, but thought it deserved mention. I now post @ F1B because of the community. The Tom’s of this site (and Peterriva’s/UAN’s/Rapiermans/etc…), and of course NC and his site contributors seem to encourage healthy debate, info-sharing, correction and questioning. I know for myself, many here have corrected my shoddy math/methodology, clarified inquiries, and argued their own cases to my points, all with humility and respect. I hope my response to you was in the same mould as those individuals that’ve made this site great.

  • Wow Guys – I take a much more simplistic approach,in this case right now RB can’t compete within the rules so they are bending them, (They need the extra flow to compete down the straights)
    I do have a question though, why would they not limit flow with a fixed size orifice? It seems dumb to restrict flow but allow teams to exceed the set amount?

    • A fixed diameter fuel route neglects the rate portion of flow rate. One needs consider the velocity/pressure of the fuel as well as the volume, the friction of the lines and also varying fuel densities (whose densities individually change depending on temp), then have a fixed-length as well as fixed diameter tube to have it work.

      Even then, there’d be no actual measuring of flow, just a physical limitation I believe the teams could overcome through reservoir and on-demand burst flow at the rails, etc.

      It’s a technical problem not easily-explained (or understood by me), but basically the teams’ cars aren’t the same, and they’d need to be for homologated fuel system lengths/diameters/functionality. The fuel composition would need to be the same AND be climate-controlled, and so on. Finally, FIA would still need some form of sensor to monitor the teams’ usages, or suffer the consequences of trusting them.

      That’s only the surface of the self-imposed difficulties FIA face; tough situation for all involved.