Jenson Button's lost podium: the BAR fuel tank and weight scandal of 2005
Jenson Button stood on the podium at Imola in April 2005, his first of the season. Within two weeks the result was gone and his team was banned from two races, all because of how much the car weighed once the fuel was drained.
The weight rule
Formula 1 has a minimum weight for the car with the driver, and in 2005 it was 600 kg. Cars are weighed after the race with the fuel drained. Fuel is heavy at the start and light at the end, so a team that can hide extra weight in the car early, and shed it late, runs lighter when it matters. That is the loophole the FIA believed BAR-Honda used.
What happened at Imola
Button finished third at the San Marino Grand Prix, with team-mate Takuma Sato fifth. After the race the FIA took Button's car away and checked its weight. According to the race report, it came in 4.99 kg under the minimum once drained. Other accounts quote slightly different amounts, which is common when reports depend on what each side said at the time.
The stewards accepted BAR's explanation. The team said the car had a secondary compartment, a collector tank, which the fuel system needed because it ran a high-pressure pump, and which always held some fuel. The FIA was not satisfied and appealed its own stewards' decision.
The hidden compartment
The FIA's case, as reported by CAR Magazine, was that this extra tank held about 13.5 litres and that, once the fuel in it burned off, the car was around 0.4 seconds a lap quicker. Race director Charlie Whiting was reported to have grown suspicious because both Hondas ran fast laps and stayed out longer than rivals. Another report says about 15 litres remained in the tank after the car was supposedly empty.
BAR's boss Nick Fry denied the team ran underweight. He said the collector had been inspected by the FIA before and that the car was never light at any point in the race. Technical director Geoff Willis told the hearing the compartment had to hold at least six litres at all times.
The verdict
The FIA International Court of Appeal heard the case in Paris on 4 May and ruled the next day. It found that BAR's fuel system effectively used fuel as ballast, which the rules do not permit. It cited "highly regrettable negligence" and a lack of transparency, but did not impose the full exclusion from the championship that the FIA had asked for, according to Crash.net.
- Both BAR cars were disqualified from San Marino and the points removed.
- BAR was banned from the next two races, Spain and Monaco, even though the team had already travelled to Barcelona.
- A six-month suspended sentence covered the remainder of the season.
- Alexander Wurz was promoted to third place at Imola.
Sato's car was not found to be underweight, but the team was punished as one entry. That is why his fifth place went too.
What is still unclear
Accounts differ on how far under the limit the car was, on the exact tank volume and on whether the minimum was quoted as 600 or 605 kg. We have used the figures that appear most often and say where sources disagree. What is not in dispute is the outcome: the result was removed, and BAR missed two races in a season in which it had only just started to look competitive.
Sources
- Wikipedia: 2005 San Marino Grand Prix
- Crash.net: Two-race ban for BAR
- CAR Magazine: Stakes upped in BAR fuel tank furore
- Tampa Bay Times archive: BAR-Honda gets 2-race ban
- Grumpy Kerb: BAR's special fuel tank compartment
Figures vary between sources. We have flagged where they disagree. Spotted an error? Tell us.
Frequently asked questions
What did BAR do wrong at the 2005 San Marino Grand Prix?
After the race Jenson Button's car was drained and weighed, and it came in about 5 kg under the 600 kg minimum. The FIA said a hidden compartment let the team carry fuel as ballast that could be used late in the race. BAR said it was a collector tank that always had to hold some fuel.
How much fuel was in the hidden tank?
Accounts differ: 13.5 litres in one report, and about 15 litres left in the tank according to the FIA. The tank's contents are central to why the car weighed more in the race than on the scales.
What was the penalty?
The FIA International Court of Appeal disqualified both BAR cars from San Marino, stripped the points, and banned the team from the Spanish and Monaco Grands Prix. A six-month suspended sentence covered the rest of 2005. The court cited highly regrettable negligence.
Did Takuma Sato's car break the rules too?
Sato's car was not found to be underweight, but the team was punished as a whole, so Sato's result was removed along with Button's.