The 1991 All Japan Sports Prototype Car Endurance Championship was the ninth season of the All Japan Sports Prototype Championship. The 1991 champion was the #23 Nissan Motorsports Nissan R91CP driven by Kazuyoshi Hoshino and Toshio Suzuki.
All races were held in Japan.
| Round | Race | Circuit | Date |
|---|---|---|---|
| 1 | All Japan Fuji 500 km | Fuji Speedway | 10 March |
| 2 | All Japan Fuji 1000 km | Fuji Speedway | 5 May |
| 3 | All Japan Fuji 500 Miles | Fuji Speedway | 21 July |
| 4 | International Suzuka 1000 km | Suzuka Circuit | 25 August |
| 5 | SUGO Inter 500 km | Sportsland SUGO | 16 September |
| 6 | Interchallenge Fuji 1000 km | Fuji Speedway | 6 October |
| 7 | SUGO Inter 500 Miles | Sportsland SUGO | 3 November |
Season results as follows: [1]
| Round | Circuit | Winning Team |
|---|---|---|
| Winning Drivers | ||
| 1 | Mt. Fuji | #23 Nissan Motorsports Nissan R91CP |
 Kazuyoshi Hoshino Toshio Suzuki | ||
| 2 | Mt. Fuji Report | #23 Nissan Motorsports Nissan R91CP |
| Kazuyoshi Hoshino Toshio Suzuki | ||
| 3 | Mt. Fuji | #36 Toyota Team TOM'S Toyota 91C-V |
| Hitoshi Ogawa Masanori Sekiya | ||
| 4 | Suzuka Circuit Report | #38 Toyota Team SARD Toyota 91C-V |
 Roland Ratzenberger  Pierre-Henri Raphanel Naoki Nagasaka | ||
| 5 | Sportsland SUGO Report | #37 Toyota Team TOM'S Toyota 91C-V |
 Geoff Lees  Eje Elgh | ||
| 6 | Mt. Fuji | #23 Nissan Motorsports Nissan R91CP |
| Kazuyoshi Hoshino Toshio Suzuki | ||
| 7 | Sportsland SUGO | #17 TWR Suntech Jaguar XJR-14 |
 David Brabham  Teo Fabi | ||
| Rank | Drivers | Number/Team | Points | Wins |
|---|---|---|---|---|
| 1 | Kazuyoshi Hoshino Toshio Suzuki | #23 Nissan Motorsports Nissan R91CP | 87 | 3 |
| 2 | Hitoshi Ogawa Masanori Sekiya | #36 Toyota Team TOM'S Toyota 91C-V | 85 | 1 |
| 3 | Geoff Lees | #37 Toyota Team TOM'S Toyota 91C-V | 54 | 1 |
| 4 |  Volker Weidler Akihiko Nakaya | #27 From A Racing Nissan R90CK | 52 | 0 |
| 5 |  George Fouche Steven Andskar | #100 Trust Racing Porsche 962C | 52 | 0 |
Sports car racing is a form of motorsport road racing which utilises sports cars that have two seats and enclosed wheels. They may be purpose-built prototypes or grand tourers based on road-going models. Broadly speaking, sports car racing is one of the main types of circuit auto racing, alongside open-wheel racing, touring car racing and stock car racing. Sports car races are often, though not always, endurance races that are run over particularly long distances or large amounts of time, resulting in a larger emphasis on the reliability and efficiency of the car and its drivers as opposed to outright car performance or driver skills. The FIA World Endurance Championship is an example of a sports car racing series.
Nissan Motorsports International, abbreviated as Nismo, is a division of Nissan Motorsports & Customizing focused in motorsport and performance-oriented car models for Nissan. Nismo was initially a company, Nissan Motorsports International Co., Ltd., formed in 1984 as a result of a merger of two motorsport departments, being the in-house tuning, motorsports and performance subsidiary of Nissan. It has competed in JSPC, JTCC, the 24 Hours of Le Mans and the 24 Hours of Daytona. They currently participate in Super GT, GT Racing and Formula E. Nismo ceased to be a company in April 2022 by being merged with sister Autech into a new Nissan subsidiary, Nissan Motorsport & Customizing.
A Le Mans Prototype (LMP) is the type of sports prototype race car previously and currently used in various races and championships, including the 24 Hours of Le Mans, FIA World Endurance Championship, IMSA SportsCar Championship, European Le Mans Series and Asian Le Mans Series. Le Mans Prototypes were created by the Automobile Club de l'Ouest (ACO). The technical requirements for an LMP include bodywork covering all mechanical elements of the car. Currently, there are three classes within Le Mans Prototypes, designated LMP1, LMP2, and LMP3.
Group C was a category of sports car racing introduced by the FIA in 1982 and continuing until 1993, with Group A for touring cars and Group B for GTs.
The World Sportscar Championship was the world series run for sports car racing by the FIA from 1953 to 1992.
The Toyota TS010 was a Group C racing car built by Toyota for the Sportscar World Championship, All Japan Sports Prototype Championship, and the 24 Hours of Le Mans.
The All Japan Sports Prototype Championship (全日本スポーツプロトタイプ選手権), abbreviated as JSPC, formed by the Japan Automobile Federation, was a domestic championship which took place in Japan for Group C and IMSA GTP prototype cars and also featured cars that were eligible for touring car racing in its earlier years. Class A and Class B for production cars which were defined by the FIA and the lead category, Class C would be for cars that are similar to IMSA's Camel Lights and the WEC's C2, whereas Class D was for C1/GTP cars.
Ray Mallock Ltd., also known as RML Group, is a motorsports and high performance engineering company, based in Wellingborough, Northamptonshire, United Kingdom.
The Nissan R90C was a platform used for Group C racing cars built in 1990 by Nissan Motors for competition in World Sportscar Championship (WSC) based in Europe and the All Japan Sports Prototype Championship (JSPC). The cars based on the basic R90C platform would compete until 1993 before Nissan chose to withdraw from sports car racing, not returning until 1997. It won three JSPC championships and several significant endurance races during its career.
The Nissan P35 was a planned Group C car built by Nissan Motors for competition in the World Sportscar Championship. Developed by Nissan Performance Technology Inc. (NPTI), which had formerly raced under the name Electramotive in the United States, the cars were intended to be completed by the middle of 1992, with competition starting in 1993. However economic troubles for Nissan led to the cancellation of the project soon after testing of the first cars had begun, meaning that the P35s never raced.
The Nissan GTP ZX-Turbo was a series of racing cars developed for Nissan Motors by Electramotive Engineering to compete in the IMSA GT Championship. Running from 1985 to 1990, they were known for being the first car to defeat the Porsche 962 which had dominated IMSA's premiere GTP category. This led to Nissan winning the constructor's championship and 12 Hours of Sebring in 1989 and 1990. During 1990, the GTP ZX-Turbo was replaced by the newer NPT-90.
The Nissan NPT-90 was a racing car developed in 1990 for Nissan Motors by Nissan Performance Technology Incorporated (NPTI), formerly known as Electramotive Engineering. It was a replacement for the highly successful GTP ZX-Turbo that had won the IMSA GT Championship in 1989. The NPT-90 would go on to win the championship in 1990 and 1991 before being retired by Nissan at the end of the 1992 season.
Richard Lloyd Racing (RLR), originally named GTi Engineering, was a British auto racing team created in 1977 by driver Richard Lloyd. Originally named for the Volkswagen Golf GTIs that Lloyd raced in the British Saloon Car Championship (BSCC), they went on to become a successful Porsche privateer in the World Sportscar Championship (WSC). Richard Lloyd Racing eventually folded at the end of the 1990 season due to the increased cost of the World Championship.
OAK Racing is an endurance racing team specialising in sports prototypes based in Le Mans, France. In 2013 it won the 24 Hours of Le Mans in LMP2 class and the 2013 FIA WEC World Champion drivers and teams on LMP2 class.
The 1993 All Japan Grand Touring Car Championship was the inaugural season of the Japan Automobile Federation All-Japan Grand Touring Car Championship and the successor series to the All Japan Sports Prototype Championship as international prototypes were in a state of flux in the early 1990s, and sportscar racing globally had switched from prototypes to grand tourers. It was marked as well as the eleventh season of a JAF-sanctioned sports car racing championship dating back to the All Japan Sports Prototype Championship.
Extreme Speed Motorsports was an American auto racing team based out of Riviera Beach, Florida. Founded by Scott Sharp and Patrón CEO Ed Brown, the team competed in the FIA World Endurance Championship, Tudor United SportsCar Championship, and American Le Mans Series since 2010 until 2018 when the team sold its equipment and race cars and shut down following an exhaustive sponsor search after the withdrawal of Patrón.
The 1992 All Japan Sports Prototype Car Endurance Championship was the tenth and final season of the All Japan Sports Prototype Championship, which would be replaced by the All Japan Grand Touring Car Championship, as sportscar racing in the early 1990s changed drastically with the decline of prototypes. The C1 class champion was the #1 Nissan Motorsports Nissan R92CP driven by Kazuyoshi Hoshino and the C class champion was the #7 and #36 TOM'S Toyota TS010 driven by Geoff Lees.
The 1990 All Japan Sports Prototype Car Endurance Championship was the eighth season of the All Japan Sports Prototype Championship. The 1990 champion was the #24 Nissan Motorsports Nissan R91CP driven by Masahiro Hasemi and Anders Olofsson.
The 1991 Fuji 1000 km was the second round of the 1991 All Japan Sports Prototype Car Endurance Championship season. It took place at Fuji Speedway, Japan on May 5, 1991.
The Ligier JS P217 is a Le Mans Prototype built by Onroak Automotive and named in a partnership with French racing driver Guy Ligier. The Ligier JS P217 was built to meet the 2017 FIA and ACO regulations for 2017 for the LMP2 category in the FIA World Endurance Championship. The car also meets the regulations for the International Motor Sports Association’s (IMSA) WeatherTech SportsCar Championship for the Prototype class. It was active in both of these championship series as well as the European Le Mans Series and Asian Le Mans Series. The prototype made its racing debut at the 2017 24 Hours of Daytona and its FIA World Endurance Championship debut at the 2017 6 Hours of Spa-Francorchamps.
