A completely new body was designed in-house by Jowett's chief bodywork designer Reg Korner, to be made by Jowett themselves. Called the Jupiter, it was an open roadster which seated three abreast, thanks to the steering column gearchange. This and the opulent curves of the body were aimed at the American market. The Jupiter was raced with some success, winning its class at Le Mans in 1950, 1951 and 1952, finishing 1st and 2nd in the 1951 Tourist Trophy and winning outright the 1951 Bremgarten Sports Car Race in Switzerland. A private Jupiter won the 1951 Lisbon International Rally outright, and Jupiters finished 1st and 2nd in class in the 1951 Monte Carlo International Rally. There were a number of wins in national rallies in the UK, France and, for example, the Lake Tahoe Rally in California in August 1952 which was an outright win by Hunter Hackney. There was a class 1-2 in the International RAC-TT of 1951 for the Jupiter, a gruelling 4-hour country-lane race.
However only 900 (including about 75 with bodywork by outside coachbuilders) were sold in four years, compared with around 23,000 Javelins.
SQM = 20.7
MPG = 26
Engine Pwr = 62.5