Roberto Guerrero CART/Champ Car results at Portland
| Year | Race # | Start | Finish | Car # | Sponsor | Chassis | Engine | Tire | Owner | Qualifying Speed | Laps | X Led | Laps Led | Status | Points |
| 1984 | 5 | 3 | 19 | 9 | Master Mechanic | March | Cosworth | Goodyear | Bignotti | 114.825 | 37 | 0 | 0 | gearbox | 0 |
| 1985 | 4 | 7 | 15 | 9 | True Value | March | Cosworth | Goodyear | Bignotti | 113.890 | 68 | 0 | 0 | accident | 0 |
| 1986 | 5 | 3 | 13 | 2 | True Value-Emerson | March | Cosworth | Goodyear | Cotter | 93.773 | 65 | 1 | 2 | accident | 0 |
| 1987 | 5 | 1 | 19 | 4 | True Value/STP | March | Cosworth | Goodyear | Vince Granatelli | 116.439 | 10 | 0 | 0 | engine | 1 |
| 1988 | 5 | 23 | 14 | 2 | STP/Dianetics | March | Cosworth | Goodyear | Vince Granatelli | 110.613 | 99 | 0 | 0 | flagged | 0 |
| 1989 | 6 | 23 | 23 | 21 | Alfa Romeo | March | Alfa Romeo | Goodyear | Morales | 112.489 | 26 | 0 | 0 | fuel injection | 0 |
| 1990 | 6 | 16 | 8 | 20 | Miller Genuine Draft | March | Alfa Romeo | Goodyear | Patrick | 116.459 | 100 | 0 | 0 | flagged | 5 |
| 1993 | 7 | 17 | 24 | 40 | Budweiser King | Lola | Chevrolet | Goodyear | Bernstein | 111.359 | 47 | 0 | 0 | contact | 0 |
