| 1998 · 1998 24 Hours of Le Mans | DNF | 35 | LM-GT1 | AMG Mercedes | Bernd Schneider · Mark WEBBER · Klaus LudwigBernd Schneider Mark Webber Klaus Ludwig | Mercedes-Benz CLK GTR | Mercedes-Benz M119 E 60 6.0L V8 | 19 | Wikipedia contributors · CC BY-SA 4.0 |
| 1988 · 1988 24 Hours of Le Mans | 2 | 17 | Gr.C1 | Porsche AG | Derek Bell · Hans-Joachim Stuck · Klaus LudwigDerek Bell Hans-Joachim Stuck Klaus Ludwig | Porsche 962 C | Porsche 935/82 3.0L F6 twin turbo | 394 | Wikipedia contributors · CC BY-SA 4.0 |
| 1988 · 800 km Jerez | 3 | 7 | C1 | Joest Racing | Bob Wollek · Klaus Ludwig | Porsche 962C | — | 188 | WSPR historical record |
| 1988 · Fuji 1000 Kilometres, Fuji Speedway | 2 | 17 | 2. C1 | Omron Porsche AG | Klaus Ludwig · Price Cobb | Porsche 962C | — | 223 | WSPR historical record |
| 1988 · 360 km Jarama | retired | 7 | C1 | Joest Racing | Klaus Ludwig · Bob Wollek | Porsche 962C | — | 62 | WSPR historical record |
| 1988 · 1000 km Monza | 5 | 7 | 5. C1 | Joest Racing | Klaus Ludwig · Bob Wollek | Porsche 962C | — | 164 | WSPR historical record |
| 1988 · 1000 km Brands Hatch | 2 | 7 | 2. C1 | Joest Racing | Klaus Ludwig · Bob Wollek | Porsche 962C | — | 239 | WSPR historical record |
| 1987 · 1000 km Monza | 4 | 8 | 4. C1 | Joest Racing | "John Winter" · Stanley Dickens · Klaus Ludwig | Porsche 962C | — | 167 | WSPR historical record |
| 1987 · 1000 km Monza | retired | 7 | C1 | Joest Racing | Piercarlo Ghinzani · Klaus Ludwig | Porsche 962C | — | 88 | WSPR historical record |
| 1987 · 200 Meilen von Nürnberg - Int. ADAC-Norisring-Trophäe | disqualified | 9 | | Joest Racing | Frank Jelinski · Klaus Ludwig · DNS - Sarel van der Merwe / | Porsche 962C | — | 153 | WSPR historical record |
| 1987 · 200 Meilen von Nürnberg - Int. ADAC-Norisring-Trophäe | retired | 7 | | Joest Racing | Bob Wollek · Klaus Ludwig | Porsche 962C | — | 76 | WSPR historical record |
| 1987 · Int. ADAC-1000-km-Rennen, Nürburgring | retired | 9 | C1 | Joest Racing | Klaus Ludwig · Bob Wollek | Porsche 962C | — | 116 | WSPR historical record |
| 1986 · 1986 24 Hours of Le Mans | DNF | 7 | Gr.C1 | Joest Racing | Klaus Ludwig · Paolo Barilla · Louis KragesKlaus Ludwig Paolo Barilla "John Winter" ( Louis Krages ) | Porsche 956B | Porsche 935/79 2.6L F6 twin turbo | 196 | Wikipedia contributors · CC BY-SA 4.0 |
| 1986 · Coppa Kouros, Monza | retired | 7 | C1 | Joest Racing | Klaus Ludwig · Paolo Barilla | Porsche 956 | — | 50 | WSPR historical record |
| 1986 · 100 Meilen von Nürnberg, Norisring | 1 | 7 | 1. C1 | Joest Racing | Klaus Ludwig | Porsche 956 | — | 79 | WSPR historical record |
| 1986 · Shell Gemini 1000 km Brands Hatch | 2 | 7 | 2. C1 | Joest Racing | Hans-Joachim Stuck · Derek Bell · Klaus Ludwig | Porsche 956B | — | 232 | WSPR historical record |
| 1986 · Shell Gemini 1000 km Brands Hatch | 5 | 8 | 5. C1 | Joest Racing | Paolo Barilla · "John Winter" · Klaus Ludwig | Porsche 956 | — | 230 | WSPR historical record |
| 1986 · Kouros 1000 Kilometres Spa | 4 | 7 | 4. C1 | Blaupunkt Joest Racing | Paolo Barilla · Klaus Ludwig · DNS - "John Winter" | Porsche 956B | — | 144 | WSPR historical record |
| 1985 · 1985 24 Hours of Le Mans | 1 | 7 | Gr.C1 | Newman Joest Racing | Klaus Ludwig · Paolo Barilla · Louis KragesKlaus Ludwig Paolo Barilla "John Winter" ( Louis Krages ) | Porsche 956 B | Porsche 935/79 2.6L F6 twin turbo | 374 | Wikipedia contributors · CC BY-SA 4.0 |
| 1985 · 1000 km Mugello | 5 | 11 | 5. C1 | Porsche Kremer Racing | Klaus Ludwig · George Fouché · Gianni Mussato | Porsche 956 | — | 184 | WSPR historical record |
| 1985 · Trofeo Filippo Caracciolo, Monza | 9 | 7 | 8. C1 | Joest Racing | Paolo Barilla · Hans Heyer · Klaus Ludwig | Porsche 956 | — | 125 | WSPR historical record |
| 1985 · Silverstone 1000 Kilometres | 6 | 7 | 6. C1 | Joest Racing | Klaus Ludwig · Paolo Barilla · Paul Belmondo | Porsche 956 | — | 206 | WSPR historical record |
| 1985 · Duschfrish ADAC 1000 Kilometres, Hockenheim | 3 | 7 | C1 | Joest Racing | Klaus Ludwig · Paolo Barilla | Porsche 956 | — | 145 | WSPR historical record |
| 1985 · 1000 km Spa | 3 | 7 | 3. C1 | Joest Racing | Klaus Ludwig · Paolo Barilla | Porsche 956 | — | 121 | WSPR historical record |
| 1984 · 1984 24 Hours of Le Mans | 1 | 7 | Gr.C1 | Newman Joest Racing | Henri Pescarolo · Klaus LudwigHenri Pescarolo Klaus Ludwig | Porsche 956 B | Porsche 935/79 2.6L F6 twin turbo | 360 | Wikipedia contributors · CC BY-SA 4.0 |
| 1984 · Trofeo Filippo Caracciolo, Monza | retired | 7 | C1 | Joest Racing | Klaus Ludwig · Stefan Johansson · Henri Pescarolo | Porsche 956 | — | 17 | WSPR historical record |
| 1984 · Sandown Park 1000 Kilometres | 7 | 7 | C1 | Joest Racing | Klaus Ludwig · Henri Pescarolo | Porsche 956 | — | 197 | WSPR historical record |
| 1984 · Grand Prix International 1000 Kilometres, Silverstone | 2 | 7 | 2. C1 | Joest Racing | Klaus Ludwig · Henri Pescarolo | Porsche 956 | — | 210 | WSPR historical record |
| 1984 · ADAC 1000 Kilometres, Nürburgring | retired | 48 | C1 | GWB Ford Zakspeed Team | Klaus Niedzwiedz · Klaus Ludwig | Ford Zakspeed C1/8 | — | 2 | WSPR historical record |
| 1983 · 1983 24 Hours of Le Mans | 6 | 8 | Gr.C | Sorga Joest Racing | Klaus Ludwig · Stefan Johansson · Bob WollekKlaus Ludwig Stefan Johansson Bob Wollek | Porsche 956 | Porsche 935/79 2.6L F6 twin turbo | 355 | Wikipedia contributors · CC BY-SA 4.0 |
| 1983 · Trophee Diners Club 1000 Kilometres, Spa-Francorchamps | retired | 43 | C | Zakspeed Racing | Klaus Ludwig · Klaus Niedzwiedz | Ford Zakspeed C1/4 | — | 30 | WSPR historical record |
| 1982 · 1982 24 Hours of Le Mans | DNF | 6 | Gr.C | Ford-Werke AG Zakspeed | Klaus Ludwig · Marc SurerKlaus Ludwig Marc Surer | Ford C100 | Cosworth DFL 4.0L V8 | 67 | Wikipedia contributors · CC BY-SA 4.0 |
| 1982 · Trofeo Filippo Caracciolo, Monza | retired | 1 | C | Ford Werke AG | Klaus Ludwig · Manfred Winkelhock · Marc Surer | Ford C100 | — | 18 | WSPR historical record |
| 1982 · The Pace Petroleum 6 Hours, Silverstone | 8 | 7 | 5. C | Ford Werke AG | Manfred Winkelhock · Klaus Ludwig | Ford C100 | — | 223 | WSPR historical record |
| 1982 · Rudolf Caracciola Wanderpreis 1000 Kilometres, Nürburgring | 20 | 7 | C | Ford Werke AG | Klaus Ludwig · Manfred Winkelhock | Ford C100 | — | 32 | WSPR historical record |
| 1982 · Trophee Diners Club 1000 kilometres, Spa-Francorchamps | retired | 6 | C | Ford Werke AG | Marc Surer · Klaus Ludwig | Ford C100 | — | 124 | WSPR historical record |
| 1982 · Shell Oils 1000 Kilometres, Brands Hatch | 5 | 1 | 3. C | Ford Werke AG | Marc Surer · Klaus Ludwig · Manfred Winkelhock | Ford C100 | — | 200 | WSPR historical record |
| 1981 · Flying Tigers 1000, Brands Hatch | retired | 1 | S+2.0 | Ford | Manfred Winkelhock · Klaus Ludwig | Ford C100 | — | 40 | WSPR historical record |
| 1980 · Nürburgring 1000 Kilometres | retired | 1 | Gr.5 | Zakspeed Racing | Klaus Ludwig · Jochen Mass | Ford Capri Turbo | — | 16 | WSPR historical record |
| 1979 · 1979 24 Hours of Le Mans | 1 | 41 | Gr.5 SP | Porsche Kremer Racing | Klaus Ludwig · Don Whittington · Bill WhittingtonKlaus Ludwig Don Whittington Bill Whittington | Porsche 935 -K3 | Porsche 930/79 3.0L F6 twin-turbo | 306 | Wikipedia contributors · CC BY-SA 4.0 |
| 1979 · Rivet Supply 6 Hours, Silverstone | entry_only | 5 | Gr.5 | Kremer Racing | Klaus Ludwig · Toine Hezemans · Axel Plankenhorn | Porsche 935 K3 | — | | WSPR historical record |
| 1979 · 25th 1000 km Nürburgring | entry_only | 102 | S+2.0 | Porsche Kremer Racing | Klaus Ludwig | Porsche 908/3 | — | | WSPR historical record |
| 1979 · 25th 1000 km Nürburgring | 2 | 2 | 2. Gr.5 | Porsche Kremer Racing | Klaus Ludwig · Axel Plankenhorn | Porsche 935/77A | — | 44 | WSPR historical record |
| 1979 · Watkins Glen 6 Hours Trans-Am and World Championship of Makes, Watkin s Glen Grand Prix Circuit | 1 | 94 | 1. Gr.5 | Whittington Brothers | Don Whittington · Klaus Ludwig · Bill Whittington | Porsche 935 K3 Tur | — | 175 | WSPR historical record |
| 1979 · Rivet Suply 6 hours, Brands Hatch | 2 | 27 | 1. Gr.5 | Porsche Kremer Racing | Klaus Ludwig · Axel Plankenhorn | Porsche 935 K3 | — | 229 | WSPR historical record |
| 1978 · 6 h Mugello | 9 | 11 | 9. Gr.5 | Gelo Racing Team | John Fitzpatrick · Klaus Ludwig · Toine Hezemans | Porsche 935/77 | — | 157 | WSPR historical record |
| 1978 · 6 h Dijon | retired | 6 | Gr.5 | Gelo Racing Team | Toine Hezemans · Klaus Ludwig | Porsche 935/77 | — | 101 | WSPR historical record |
| 1978 · 6 h Silverstone | retired | 6 | Gr.5 | Gelo Racing Team | Klaus Ludwig · Derek Bell · Hans Heyer | Porsche 935/77A | — | 111 | WSPR historical record |
| 1978 · 1000 km Nürburgring | retired | 1 | Gr.5 | Gelo Racing Team | Toine Hezemans · Klaus Ludwig · John Fitzpatrick | Porsche 935/77 | — | 22 | WSPR historical record |
| 1978 · 1000 km Nürburgring | 1 | 3 | 1. Gr.5 | Gelo Racing Team | Klaus Ludwig · Hans Heyer · Toine Hezemans · DNS - Derek Bell | Porsche 935/77 | — | 44 | WSPR historical record |
| 1978 · Misano 6 Hours | retired | 6 | Gr.5 | Gelo Racing Team | Toine Hezemans · Klaus Ludwig · John Fitzpatrick | Porsche 935/77A | — | 137 | WSPR historical record |
| 1978 · 6 h Vallelunga | 3 | 9 | 3. Gr.5 | Gelo Racing Team | Klaus Ludwig · John Fitzpatrick · Toine Hezemans · DNS - Hans Heyer | Porsche 935/77 | — | 266 | WSPR historical record |
| 1977 · 1977 24 Hours of Le Mans | DNF | 38 | Gr.5 SP | Gelo Racing Team | Klaus Ludwig · Toine Hezemans · Hans HeyerKlaus Ludwig Toine Hezemans Hans Heyer | Porsche 935 | Porsche Type-935 2.9L F6 turbo | 15 | Wikipedia contributors · CC BY-SA 4.0 |
| 1977 · 1977 24 Hours of Le Mans | DNF | 39 | Gr.5 SP | Gelo Racing Team | Klaus Ludwig · Tim Schenken · Hans Heyer · Toine HezemansKlaus Ludwig Tim Schenken Hans Heyer Toine Hezemans | Porsche 935 | Porsche 2.9L F6 turbo | 269 | Wikipedia contributors · CC BY-SA 4.0 |
| 1976 · ADAC 1000 Kilometres, Nürburgring | retired | 51 | Gr.5 | Zakspeed | Klaus Ludwig · Peter Hennige | Ford Escort RS 2000 BDG | — | 3 | WSPR historical record |
| 1975 · 1000 km Nürburgring | retired | 53 | GT+1.6 | Gelo Racing Team | Manfred Schurti · Klaus Ludwig · DNS - Claude Ballot-Léna | Porsche Carrera RSR | — | 27 | WSPR historical record |
| 1973 · ADAC 1000 Kilometres, Nürburgring | 21 | 78 | 2. T3.0 | Anzeiger | Klaus Ludwig · Lothar Pinske | Ford Capri RS | — | 32 | WSPR historical record |