What made BMW strong in the last part of the 1983 season was not only their slik pitstop actions, but what was in the fuel tanks. They had a clear horsepower advantage in the last 6 races. That jump did not come from an engine update but from the fuel that was pumped in it. The engine only needed a bigger turbocharger to exploit the advantages of the fuel-mix.
BMW Motorsport had reached the limit of what could be extracted from this engine. It was almost the same engine they started the F1 project with at the end of the late 1970’s. Attempts to put more than 650 bhp through the engine led to detonation and failures.
BMW boss Paul Roche looked for a solution. He’d heard that Ferrari, which was considered to have the strongest engine on the grid, was experimenting with water-injection as a solution to the same problem. So, BMW also started with that. But nothing changed. Then they started with fuel experiments. Roche found out that there was unleaded aviation fuel developed in Germany during WWII by a group of companies, supervised by BASF.
In BASF subsidiary Wintershall, they found an expert. He came up with the idea of a synthesised designer fuel that decreased the percentage of easily-ignited hydrocarbon compounds and increase the amount of slower-burning compounds. Remember that fuel regulations in those days were only a few lines in the F1 regulation rule book. Rumours say that the BMW fuel was high on toluene.
At Hockenheim race came the first test. The benefit was not felt immediately, but two weeks later the bigger turbo arrived. And Piquet was on pole!
Alain Prost still now is convinced that this fuel changed the dynamics of the 1983 season and that it was the reason he lost the championship to Piquet. And he still believes it was illegal fuel. But Renault’s supplier, Elf, saw no reason to protest. That was all about commercial agreements.
But protest from Renault could have brought dividends. Samples of the BMW fuel were taken at Hockenheim and Monza and tested at the Institut Francais du Petrole by the FISA. The results showed a high octane rating, just over the maximum. As this was within the tolerance limit, the fuel was considered legal.
But, the results of these test were leaked to Elf and more, sources within the Institut were claiming that the fuel was in no way legal. That leak came around the eve of the prize-gala event after the season in December. Technical man at that time, Gabriele Cadringher, suggested that it was all a huge misunderstanding between BASF, FISA and the Institute de Petrol. There was never to be an intention to cheat. And more, every time there were multiple samples taken at the tests. And it should have been normal to test the second sample in a second laboratory.
It is all academic because all teams got to work to develop their own exotic fuels for 1984.
Publication: 02/10/2025Back to overview
