Apparently the Honda engine needs at least 5.29 liters of fuel in the collector in order to run without sputtering during idle.
Here's a good long commentary from Atlas before the decision was made:
"After the finish of the 1985 San Marino Grand Prix, the McLaren of race winner Alain Prost was found to be 2kgs underweight. The Frenchman was of course disqualified - it was black and white, even if the discrepancy was a result of a genuine mistake by his team.
Exactly 20 years on, Jenson Button's third placed BAR 007 was found to be almost 5.4kgs under the weight limit at the same event - a margin nearly three times the one that caught out Prost, and this in an era when the technical checks and weighing equipment are far more sophisticated. And yet on this occasion Button was not disqualified.
If many in the paddock found this strange, to say the least, the FIA itself was so flabbergasted by the decision made by the stewards on Sunday night at Imola that it has appealed against the judgement of the three wise men acting in its name. It's a move not totally without precedent in recent motor sport history, but a rare one all the same.
This is an unusual story, worthy of the secret agent who shares his name with the type number of the car. Many of the facts are yet to emerge, but having spoken to some well-informed people - although not from BAR, as no one is talking - Autosport-Atlas attempts to piece the basics together.
The Man with the Golden Endoscope
Things began to develop in the couple of hours after the end of the race. Post-race technical checks were a formality for most, and once the cars had been examined, they were pushed into the double garage that served as parc ferme. Normally, if there are no issues, the results are made official a little more than an hour after the race, at which point all the cars are then released back to the teams, and packed away in the transporters.
But last weekend there was a problem. Wandering past the FIA end of the pits, amid the usual noisy chaos that follows any race in Italy, one could sense that something wasn't quite right. At a time when usually everything was done and dusted, not only were most of the cars still parked forlornly in parc ferme, but one - Button's BAR 007 - was still in the FIA garage, sitting on the weighbridge. Officials surrounded it, while BAR race engineer Craig Wilson stood by its nose.
At times like this, information is thin on the ground. Nobody announces on the tannoy "there's a problem with car number three," and no paperwork is circulated. Things are done very discreetly until there is definite news. Only if you see it with your own eyes do you know that something is up.
Among those quick to spot that a drama was unfolding were Renault team manager Steve Nielsen and Williams's chief mechanic Carl Gaden, who stood on the pitlane side of the FIA garage and watched with some interest, ready to report back to their bosses on any developments. Although no information emerged, the fact that they could watch, albeit from a distance, gave the proceedings a degree of transparency.
When the car was pulled off the weighbridge and pushed back on, it was only too clear that this was a weight issue. And when FIA technical delegate Jo Bauer was seen with his arm inside the fuel tank, having a good feel around with his trusty endoscope, it was obvious that there was also a fuel element to the story.
With nothing coming out of the FIA, I decided to investigate. I bumped into Button himself down at Red Bull, where his pal David Coulthard was about to give him a tour of the new monstrous motorhome. "Is there a problem with the weight of your car?" I asked. He made it pretty clear that he thought there wasn't.
The best way to find out what's going on in situations like this, is to ask the other teams, and it was surprising how many important folk hadn't even realised that the BAR was still being checked. In fact, it was hard to miss from the paddock side, as the FIA garage door was open by a metre, and the 007's nose was clearly visible.
Later I came across Alex Wurz, celebrating his fourth place at Bernie Ecclestone's hospitality bus. "Don't celebrate yet," I said. "You might end up third..."
The Weight is Not Enough
There are in fact two minimum weight figures in Formula One's 2005 regulations. The first covers qualifying, when cars have to weigh more than 605kgs. They are measured at the end of each lap, with the driver on board.
Of course, under current regulations, the only figure that really matters is that measured after the first qualifying session, when you are not using race fuel. Obviously every team put the bare minimum into the car, and judge things finely so that after the out-lap, flying lap, and in-lap, they come in as close to 605kgs as they dare. That's why an engineer might tell a driver 'try to save fuel' on his in-lap on Saturday, even if it's not a question of saving it for the race.
On Sunday morning, the cars are again weighed with the driver. Of course, with race fuel now on board, there is no way anyone will be near the minimum limit. Nevertheless, those figures are crucial to the FIA because they are in effect the starting weights that have to be maintained for the start of the race.
The post-race check is different. For obvious reasons, there is no way to have the entire field queue up for weighing, so the drivers get out and are weighed on their own, before the cars are measured separately. The two figures are added together to produce a total.
Post-race, the required limit drops to 600kgs. This is a by-product of the race fuel/parc ferme rules. With the agreement of the teams, this 5kgs margin was introduced to allow for loss of weight due to consumption of oil, brakes, and other materials. Also factored in is loss of weight by the driver (although some of what he sweats off might be absorbed by his overalls, and is therefore still in the equation).
In theory, because of parc ferme, apart from the losses outlined, there is no other reason to account for a difference in weight from the end of first qualifying to the end of the race - apart, of course, from fuel.
At Imola, the BAR weighed 606.1kgs with its fuel on board, well above the limit and in fact a little higher than cars normally are at the finish. Teams would normally expect to be down around the 603kgs mark, allowing for the aforementioned loss of materials and finishing with the bare minimum of fuel on board. In fact, you have to have at least a litre in the car so that samples can be taken and tested by the FIA, or you could face disqualification.
This is where it gets interesting. Since refuelling was introduced in 1994, the FIA has reserved the right to do a more detailed weight check, involving draining the car of its fuel to determine its dry weight.
The logic is simple: if the fuel is pumped out and the car weighs less than 600kgs with no fuel on board, then the clear implication is that at various points during the race - i.e. immediately before its pitstops - the car could have been running at less than 600kgs. It has always been understood that weighing the car without fuel is the only way to demonstrate that a car was legal throughout the race. The subject has been discussed many times in meetings of the FIA Technical Working Group and of team principals. As long ago as 1994, the FIA clarified that this was the case in response to questions from teams.
One senior technical guy explained it thus this week: "There was a communication stating that the FIA would drain the car of all fuel, and the car had to comply to the weight limit in that condition. That was the only condition in which they could be sure that a team was legal during the race. And that's always been clearly understood. That's always been one of the key principles, and it's been mentioned many times. It's not strictly in the regulations, but it does say that the car must be legal at all times, and it also says that the FIA technical delegate must be satisfied that the car complies with the regulations."
But is a clarification issued several years ago still valid today? "I don't see why not, but BAR may claim they weren't in F1 then..."
Like random drug tests, fuel drain checks can happen without warning. At Imola, the top three cars were all drained, and all three were found still to be above the limit. Normally, that should have been the end of it. However, Jo Bauer was still interested in the BAR. He asked the team's representative if there was any more fuel in the car. He, apparently, said no.
It was a classic 'Colombo Question' - that last, subtle enquiry that leads to the unmasking of the villain.
It was then that Bauer began to take a close look at the inside of the 007 fuel tank. He found an extra compartment with fuel still in it. The compartment itself was not illegal - F1 tanks are not gaping caverns, they all have complex innards, and, it seems, what BAR had was acceptable in technical terms.
But what mattered here was that the fuel inside it had not come out with the initial draining, and when asked, the team's representative had denied that there was any more on board. When this 'hidden' fuel was drained, the car tipped the scales at 594.6kgs. On the face of it, bearing in mind that dry weight has always been the only benchmark of whether a car could be running underweight, Bauer could come to no other conclusion - BAR literally had the capacity to cheat.
On Max Mosley's Secret Service
Bauer's pursuit of the truth was no accident. Over the off-season a story had done the rounds that BAR might have been doing something 'unusual' during last season. It seems that the tale emerged after a mechanic left and joined a rival (British) team. A leading technical person at that team shared this information with his opposite number at a rival outfit when they bumped into each other at a test (he may well have confided in others), and the matter was also discussed with the FIA.
Nothing could be done during the winter, so it was just a case of waiting for the season to start. In Australia, the BARs pulled out on the last lap to gain new engines for the second race, but they were still classified and thus eligible for scrutineering. But as the performance was so bad, they were not really of interest. Two double retirements followed in Malaysia and Bahrain. Then Button finished third in Imola, just 10 seconds behind the winner. It seemed like a pretty good time to do a check.
The FIA does not act on pitlane gossip alone, and disgruntled ex-employees are not always arbiters of truth. But the governing body also keeps a very close eye on what teams are doing with fuel, and runs software that makes use of two key pieces of information: the pre-race weights, which indicate how much fuel is in the cars for the start, and fully accurate fuel rig readings. The FIA delegates do not rely on the stop timings shown on TV, as observers like you and I have to. Their detailed data can be analysed, and any strange patterns are flagged.
You Only Refuel Twice
So what are BAR accused of doing, and what benefits might have accrued? First of all, consider that a lap of Imola requires around 3.0kgs of fuel - a number verified by more than one top team. We know that at the end of the race some 11.5kgs were pumped put of BAR - in other words, enough to run very nearly four laps. According to information from other teams, F1 cars rarely finish with more than a lap's worth of fuel in the tank. Yes, there has to be some left for the FIA to check, but saving fuel to pass a weight check is not an issue as there is that 5kgs built-in margin to play with.
Since the BAR weighed 606.1kgs at the end, we have concrete proof that the car could not have run below the limit for the last stint of the race. What the FIA is looking at, however, is the couple of laps prior to each of the team's two stops.
Jenson Button stopped at the end of lap 24 and lap 48 of the San Marino Grand Prix. However, the first tank also included the lap to the grid, and the formation lap. As the drivers are in fuel saving mode, those add up to exactly one racing lap. So his stop schedule, including the slowing down lap, was roughly as follows:
25 laps - 24 laps - 14.5 laps
Or in fuel terms:
75kgs - 72kgs - 55kgs (43.5 'used', plus 11.5 pumped out)
The only times the car could have possibly run under 600kgs are laps 23-24, and 47-48. Did the team dip into that 6kgs 'reserve' or not? Did it genuinely pit with the cars at 600kgs rather than, say, 596kgs? The only proof that can answer that is the data provided by the team, and of course the fuel consumption figures are absolutely paramount. That is the heart of the argument.
If you think a couple of laps marginally under 600kgs are not worth worrying about, think again. In such a case, there are benefits to be gained for the whole of the first two stints, i.e. 48 laps.
The following figures need not apply in this case, but they explain why the FIA would take the matter very seriously. Let's assume the car was run down to 596kgs, leaving just enough to get it back to the pits safely. If we assume that everyone else has a dry weight of at least 605kgs, the qualifying minimum, then a car using this technique will in effect weigh 9kgs less than another car running to an identical pitstop strategy for the whole of those 48 laps. At Imola, 3kgs - or a lap of fuel - is worth exactly one tenth of a second. So the car concerned would gain 0.3 a lap for 48 laps - or a total of 14.4 seconds. That is a huge amount.
Another way to look at this is that for a given genuine starting weight, this car could run three laps longer to the first stop than a car of identical weight. At a time when even one lap means the difference between winning and losing, that's pretty handy.
In addition, in second qualifying the car would be carrying 9kgs less than any other car that plans to pit on the same lap, which equates to three tenths of a second benefit in the battle for grid position. Worth having, of course.
Even if the fuel is run down only to a legal 600kgs - something no other team would have the capability to do - there are similar, albeit smaller, benefits.
There is one other interesting aspect to qualifying. In effect, to meet the 605kgs limit the car would have to carry at least 11kgs of 'spare' fuel in that first session. There are restrictions as to where you can locate traditional ballast, but could this lump of fuel, located handily in the middle of the car, influence the handling balance over the one flying lap? Having weight further back in the car could be of specific help to a Michelin user.
Having said that, fuel is not very efficient as ballast. Says our technical source: "It's high volume and it moves around, and it's going to be high in the car. It wouldn't be our first choice."
And there's yet another possible benefit. Did the team need to keep 6kgs (or more) of fuel permanently in the car to help the fuel system operate effectively, in terms of pressure and pick-up and so on?
That is not an uncommon problem, and indeed it happened to at least one leading team in the searing heat of Bahrain. They had no choice but to keep a certain minimum amount of fuel in the tank all the way to finish so that it didn't splutter to a halt before its pitstops or the chequered flag. Frustrating, but part of the game, and everyone accepts that. It could just be that BAR built in the 6kgs margin so that this fuel could be carried with no penalty in time and weight.
"How often have you heard a team say 'we're a bit heavy because we've got a fuel pick-up problem'?" says our technical guy. 'And they don't say 'we've got a permanent offset of 6-7kgs or whatever because we need that amount in reserve for the fuel system'..."
For Your Tank Size Only
Back to Sunday night. With the checking complete, the car was left alone on the weighbridge. The action now moved upstairs, to Charlie Whiting's office and that of the stewards, just along the corridor. Meanwhile, back in the engineering offices in the BAR transporter, technical director Geoff Willis was putting his evidence together. He emerged carrying some files and headed off to see the FIA, accompanied by Craig Wilson and team manager Ron Meadows. Jo Bauer presented his findings to the three race stewards, who consulted with Whiting and made a judgement after reviewing evidence from Willis.
For several hours, no information was released from the top floor. Darkness came and it began to rain, while up and down the paddock frustrated mechanics kicked their heels. If there is a problem with one car, then all cars have to stay in parc ferme. You don't just get a car back after the race and stick it in the truck - there's a list of jobs to run through, which often involves firing up the engine. They just had to wait.
Williams were in particular trouble, as BMW wanted its V10s out of the chassis for examination in Munich. Alas, everyone had to wait until the BAR business was sorted out. Team members booked on Sunday night flights realised that they had no chance of catching them, and there was much frantic rebooking for Monday. Legal or not, BAR wasn't about to win a popularity contest in the paddock...
Finally, some hard news emerged. The official results, unchanged, were declared and signed off at 10.10pm, and a document issued by the stewards was timed at 9.30pm, and counter signed by BAR's Ron Meadows at 9.42pm. It appeared to be very carefully worded, and created more questions than it answered.
It stated that in Jo Bauer's opinion "Jenson Button is able to run below the minimum weight limit" - as clear an accusation of cheating you are going to get, although the use of "able" was intriguing. But it went on to say that the stewards had decided that the matter "requires no further action."
Usually the stewards pretty much rubber stamp whatever they've been told, and their main job is to decide what the penalty should be. But on this occasion, the three - local Giuseppe Muscioni, Swiss Paul Gutjahr, and Japanese Katsutoshi Tamura - chose to side with the team, effectively ignoring the recommendations suggested by Bauer.
Not surprisingly, the decision caused some disappointment among those in the FIA whose job it is to seek out rule infractions. Even on Sunday night there were suggestions that the matter would go further, which could only mean an appeal by the FIA against the stewards' decision.
Nevertheless, it was surprising that as early as Monday morning the FIA announced that it was going to do exactly that, giving itself and BAR some nine days to put their respective cases together before meeting in Paris on Wednesday May 4. Quite simply, Whiting and Bauer had informed FIA president Max Mosley that they did not share the stewards' interpretation of the evidence, and that this was too important an issue to let go.
Disputes Are Forever
There are two related but distinctly different issues here, and BAR had to convince the stewards on both matters.
In effect, BAR's case was that A) The 'dry' weight is irrelevant as the rules are written; and B) the car never ran below 600kgs during the course of the event.
In case A, the team's behaviour seems to be based on a bit of lateral thinking by Willis, one of the smartest men you'll meet in an F1 paddock - in fact he had a hand in writing the rules that govern the design of America's Cup yachts.
He's clearly taken the view that, as written, the rules do not expressly say the car has to weigh 600kgs when drained of fuel, only that it has to be above 600kgs during the event. However, the FIA's position is a simple one: the only way to police this issue is to drain the car, and that's the way it has always been.
BAR may well be right to claim that nowhere in the 2005 rules does it explicitly say the car must weigh 600kgs without fuel. They may argue that just because it's always been understood that this is the method of checking, doesn't mean that it is sacrosanct.
But one could equally argue that there is nothing that specifies exactly how the FIA determines whether a car has a maximum of 10 cylinders, or indeed four wheels. The legal battle over such niceties promises to be an interesting one.
No one can possibly dispute that, as the Sunday night statement said, "Jenson Button is able to run below the minimum weight limit." But whether he did or not is another matter. Is being able to cheat illegal in itself? That's going to involve some serious debate over semantics, and views will undoubtedly be divided.
In case B, the team used their data to convince the stewards that at no time did the car fall below a weight of 600kgs. That in effect meant demonstrating that at each of the pit stops, there were at least 6kgs - or two laps - of fuel still in the car.
Of course, the FIA already knew how much went into the car at each stop, and how much was drained out at the end. But it did not have a precise figure for how much fuel was in the car at the start - only a guestimate based on starting weight and the drained weight that could not accurately allow for any loss of materials, as discussed earlier.
Crucially, BAR were also able to present fuel consumption figures. It was this information, provided by the team and not verified as such by the FIA, which convinced the stewards that the car never dipped below 600kgs.
So the bottom line is that the stewards must have agreed with BAR's unique interpretation of the rules, and believed that the car did at no point run below 600kgs. These are the two matters on which Whiting and Bauer did not share the opinion of the stewards, and caused them in effect to take the matter to Max Mosley. The same two points are what will be debated in the appeal on May 4.
But there is another issue. In effect, BAR are openly admitting that they were using fuel as ballast. Once again, they are pursuing a unique interpretation of the rules, which state that any ballast has to be fixed and require tools to remove it. If you pump fuel out, are you using tools?
Fry Another Day
In his press statement following the FIA's appeal, BAR-Honda CEO Nick Fry said that two blue chip companies like Honda and BAT would not expose themselves to something so potentially damaging as breaking the Formula One regulations. Such an argument is unlikely to stand up in court - it's a bit like OJ Simpson claiming he's a sporting legend so therefore he's obviously innocent - but nevertheless, Fry has a good point.
BAR have plenty of good, solid people - including Fry himself, technical director Geoff Willis, team manager Ron Meadows, chief mechanic Alistair Gibson, and the hard working guys on the race crew. But clearly something strange is going on.
What might have happened is that Willis has targeted what he sees as a loophole - i.e. that the car does not have to be 600kgs without fuel. It could well be that the car never dipped below 600kgs, either at Imola or prior to any of last year's many pitstops, and thus there has been no actual flouting of the minimum weight requirement.
But it's a dangerous game to rely on your own interpretation of a situation like that, without first checking with the FIA, and specifically Charlie Whiting. As our technical guy says: "If they had a special requirement, why didn't they spell it all out to the FIA before they started to use it, and get the whole thing cleared?"
BAR were reprimanded by the FIA last year for running a previously outlawed electronics system during Friday practice for the German Grand Prix, something which lead Ferrari's technical director Ross Brawn to state back then: "I guess Geoff [Willis] was not around in those days and he came up with a system that clearly contravened the clarifications that the FIA had given the teams a few years ago. We were a little bit shocked about it." Sounds familiar?
Two questions remain. Was the 6kgs in fact movable ballast and therefore illegal full stop? And most importantly, what was the story with the fuel that was in the now infamous 'secret compartment'? Why did the team's man on the spot claim there was no more fuel to be found?
One possible explanation is that, for whatever reason, the team hedged their bets. They came up with an interesting and quite possibly valid interpretation of the weight regulations, and they genuinely never ran less than 600kgs. But just to make sure that they would never have to face a tricky legal challenge, they ensured that the fuel used as ballast was not easily found in a spot check. If that is the case, being economical with the truth could prove to be a major error.
"It doesn't make any sense," says our technical guy. "If they had any grounds to do what they did, why did they deny that they had it? It has serious implications, really. It's not very often that blatant cheating is found in F1. Some issues are contentious because they're down to interpretation, and I guess that's what they're going to try and argue.
"But if I had a bottle of nitrous oxide on the car and told the FIA I never gave the instructions to put that into the engine, and I can prove it, it wouldn't be looked on very favourably! My guess at the moment is that they are trying to be smart on something or other that we don't understand, and it's going to have more serious implications for them than they probably thought about."
One strange thing is that the legality of Takuma Sato's car, which finished the San Marino Grand Prix in fifth place, was not questioned in that same post-race scrutineering. It would be stranger still if it turned out not to be built to the same spec as its sister car, of course.
So what are the possible penalties should BAR be found guilty to any degree? Comparisons with the Toyota disqualification from the 1996 season of WRC have been made, and indeed Max Mosley made it clear earlier this year that he will take a tough stance on any blatant F1 misdemeanours. It could get messy.
Those who confuse the focus by Bauer and Whiting on the BAR at Imola with the political atmosphere in the F1 paddock these days - with the FIA, FOM and Ferrari in one side, against the GPWC and their allied teams in the other - are misguided. Bauer and Whiting were doing their job. It would be just as silly to suggest that the Japanese steward, a man inevitably with some connections to Honda-owned Suzuka, would in any way be compromised. Having said all that, BAR and Honda do seem to have given Messrs Mosley and Ecclestone a ball that they can take up and run with, and they rarely waste such opportunities...
At the very least, we can expect the hearing in Paris next week to end with a clarification de facto of the 600kgs rule. Whatever else happens on May 4, the FIA is between a rock and a hard place. If the stewards are overruled, then their authority and that of the whole system is weakened. If the FIA loses, then the standing of Charlie Whiting and Jo Bauer will suffer - not to mention that of Mosley, who has backed their hunch."