1985 San Marino Grand Prix

Limited fuel allowances played a big part in the race, as a succession of drivers ran out of fuel in the last few laps. Prost took the chequered flag before stopping on the slowing-down lap and hitching a ride with Patrick Tambay on the side pod to return to the pits. Later, Prost's car was found to be 2 kg (4.4 lb) below the minimum permitted weight in post-race scrutineering, resulting in his disqualification. Summing up the general feeling that FISA's fuel limit rules had seen Formula One races reduced to mere economy runs, Williams driver Nigel Mansell noted that "it wasn't really racing".

Following this, until the end of the turbo era at the end of 1988, McLaren drivers would routinely pull up just beyond the finish line after a race so as to leave as much fuel in the tank as possible and avoid being underweight. It would actually become a common sight during this time to see all finishing cars pulling up just beyond the line in order to beat the weight limit.

Stefan Johansson ran a good race in his second drive for Ferrari. After starting 15th he steadily made his way through the field and by late in the race had moved to second (benefiting from others running out of fuel) and was poised to benefit from Senna also running dry 3 laps from home. Johansson took the lead from the Lotus to a thunderous applause from the Tifosi, only to run out of fuel himself half a lap later coming out of the Acque Minerali chicane. A post race examination of his car revealed the Ferrari had an electrical malfunction and a tiny, barely visible crack in the turbo pipe that caused the engine to use more fuel than the readout was telling the team or Johansson. The Ferrari's readout had told Johansson that he still had enough fuel to finish the race.

Prost's disqualification promoted de Angelis to the win, his second and last in F1, even though at no point did he ever actually lead the race. Second place was thus awarded to Boutsen — who ran out of fuel as he reached the start-finish straight on his final lap and pushed his Arrows-BMW across the finish line to secure his finishing position (unlike Prost's McLaren, the Arrows was still over the weight limit), with third going to Frenchman Patrick Tambay who had won the race for Ferrari in 1983, his 2nd of two F1GP race wins. This would turn out to be the last podium finish for both Tambay and the original factory Renault team.

Mauro Baldi and Spirit Racing entered their last Grand Prix: the small British team were having financial troubles and the Toleman team, via their new major sponsor, Italian fashion house Benetton, offered to buy the Spirit team. The offer was accepted and the Benetton Group immediately transferred Spirit's existing Pirelli tyre contract to Toleman, allowing them to race from the next round in Monaco.

Pos	No	Driver	Constructor	Laps	Time/Retired	Grid	Points
1	11	Elio de Angelis	Lotus-Renault	60	1:34:35.955	3	9
2	18	Thierry Boutsen	Arrows-BMW	59	Out of fuel	5	6
3	15	Patrick Tambay	Renault	59	+ 1 Lap	11	4
4	1	Niki Lauda	McLaren-TAG	59	+ 1 Lap	8	3
5	5	Nigel Mansell	Williams-Honda	58	Out of fuel	7	2
6	28	Stefan Johansson	Ferrari	57	Out of fuel	15	1
7	12	Ayrton Senna	Lotus-Renault	57	Out of fuel	1
8	7	Nelson Piquet	Brabham-BMW	57	Out of fuel	9
9	3	Martin Brundle	Tyrrell-Ford	56	Out of fuel	25
10	16	Derek Warwick	Renault	56	+ 4 Laps	14
DSQ	2	Alain Prost	McLaren-TAG	60	(1:33:57.118) Underweight	6
Ret	23	Eddie Cheever	Alfa Romeo	50	Engine	12
NC	24	Piercarlo Ghinzani	Osella-Alfa Romeo	46	+ 14 Laps	22
Ret	27	Michele Alboreto	Ferrari	29	Electrical	4
Ret	9	Manfred Winkelhock	RAM-Hart	27	Engine	23
Ret	10	Philippe Alliot	RAM-Hart	24	Engine	21
Ret	6	Keke Rosberg	Williams-Honda	23	Brakes	2
Ret	26	Jacques Laffite	Ligier-Renault	22	Turbo	16
Ret	29	Pierluigi Martini	Minardi-Motori Moderni	14	Turbo	19
Ret	25	Andrea de Cesaris	Ligier-Renault	11	Spun off	13
Ret	21	Mauro Baldi	Spirit-Hart	9	Electrical	26
Ret	8	François Hesnault	Brabham-BMW	5	Engine	20
Ret	4	Stefan Bellof	Tyrrell-Ford	5	Engine	24
Ret	17	Gerhard Berger	Arrows-BMW	4	Engine	10
Ret	22	Riccardo Patrese	Alfa Romeo	4	Engine	18
DNS	30	Jonathan Palmer	Zakspeed	0	Engine	17
Source:[1][2]

• Boutsen, Mansell, Johannsson, Senna, Piquet and Brundle were classified as they had completed more than 90% of the race distance.
• Alain Prost finished first, but was disqualified as his car was found to be underweight.

• Note: Only the top five positions are included for both sets of standings.

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