It was designed by Ross Brawn and John Piper, and was built and run by Tom Walkinshaw Racing (TWR), on behalf of Jaguar Cars.

The 1991 season marked the introduction of the FIA’s new, and controversial, 3.5 Litre Formula which replaced the highly successful Group C category that had been used in the World Sports Car Championship since 1982.

The new design targeted a lower kerb weight of 1,650 lb (748 kg) and higher downforce levels meant that the XJR-14 was a lot faster in corners compared to the previous Group C front runners.

In the early part of the 1991 World Sportscar Championship season the XJR-14 was in a league of its own, totally outclassing its rivals and in particular the Peugeot 905 and Mercedes-Benz C291.

The fact that Jaguar already had a race proven engine certainly helped the team’s cause, but the rest of the car was far superior to its rivals.

This meant a hard fight with the new and quickly improving Peugeot squad for the rest of the season, but Jaguar was able to hold on and secure the manufacturers title with 3 victories.

Although the XJR-12s did not manage to win, Jaguar's decision not to run the untested XJR-14 was vindicated by the fact that Peugeot's 905 failed to finish the race.

Meanwhile, TWR had reached an agreement to supply more XJR-14 chassis to Mazda, minus the Cosworth V8s but installed with Mazda-badged Judd V10s for the World Sportscar Championship.

Its most significant feature was that it had the roof removed, turning it into an open cockpit prototype to run under the then-new LMP regulations.

691/192 - 1991: Suzuka (DNF), Monza (2nd), Silverstone (1st), Nurburgring (2nd), Magny Cours (3rd), Mexico (did not race), Autopolis (3rd), Sugo (1st).

1992 (chassis number changed to 192): Mid-Ohio (1st), New Orleans (4th), Watkins Glen (3rd), Laguna Seca (3rd), Portland (DNF), Phoenix (2nd), Del Mar (3rd-DNF).