PORTUGUESE GRAND PRIX - PRACTICE 1
22 Sep 1991
Autódromo do Estoril, Portugal
| Pos. | No. | Driver | Team | Time / Gap | 
|---|---|---|---|---|
| 1 | 6 | Riccardo PatresePAT | Williams Renault | 1:14.158 | 
| 2 | 2 | Gerhard BergerBER | McLaren Honda | +0.613s | 
| 3 | 1 | Ayrton SennaSEN | McLaren Honda | +0.687s | 
| 4 | 33 | Andrea de CesarisDEC | Jordan Ford | +1.174s | 
| 5 | 5 | Nigel MansellMAN | Williams Renault | +1.797s | 
| 6 | 32 | Roberto MorenoMOR | Jordan Ford | +1.973s | 
| 7 | 20 | Nelson PiquetPIQ | Benetton Ford | +2.121s | 
| 8 | 27 | Alain ProstPRO | Ferrari | +2.140s | 
| 9 | 16 | Ivan CapelliCAP | Leyton House Ilmor | +2.365s | 
| 10 | 23 | Pierluigi MartiniMAR | Minardi Ferrari | +2.536s | 
| 11 | 22 | Jyrki JarvilehtoJAR | Dallara Judd | +2.573s | 
| 12 | 24 | Gianni MorbidelliMOR | Minardi Ferrari | +2.595s | 
| 13 | 28 | Jean AlesiALE | Ferrari | +2.643s | 
| 14 | 15 | Mauricio GugelminGUG | Leyton House Ilmor | +2.850s | 
| 15 | 21 | Emanuele PirroPIR | Dallara Judd | +2.872s | 
| 16 | 4 | Stefano ModenaMOD | Tyrrell Honda | +2.971s | 
| 17 | 25 | Thierry BoutsenBOU | Ligier Lamborghini | +3.646s | 
| 18 | 3 | Satoru NakajimaNAK | Tyrrell Honda | +3.712s | 
| 19 | 29 | Eric BernardBER | Lola Ford | +4.212s | 
| 20 | 7 | Martin BrundleBRU | Brabham Yamaha | +4.311s | 
| 21 | 9 | Michele AlboretoALB | Footwork Porsche | +4.341s | 
| 22 | 26 | Erik ComasCOM | Ligier Lamborghini | +4.491s | 
| 23 | 30 | Aguri SuzukiSUZ | Lola Ford | +4.689s | 
| 24 | 12 | Johnny HerbertHER | Lotus Judd | +4.739s | 
| 25 | 19 | Michael SchumacherMSC | Benetton Ford | +4.785s | 
| 26 | 17 | Gabriele TarquiniTAR | AGS Ford | +5.156s | 
| 27 | 11 | Mika HakkinenHAK | Lotus Judd | +5.569s | 
| 28 | 8 | Mark BlundellBLU | Brabham Yamaha | +5.662s | 
| 29 | 35 | Eric van de PoeleVAN | Lambo Lamborghini | +5.885s | 
| 30 | 34 | Nicola LariniLAR | Lambo Lamborghini | +8.157s |