1979: Production improvements

April 

The following enhancements were introduced to 1979 model year: Revised thicker quality carpet which included the carpet on the “kick” door trim boards, A revised steering wheel impact pad was introduced, Legislation regarding the introduction and use of seat belts meant there were many different specification set-ups depending on the receiving market, Electric aerial with stainless steel low profile mast mounted on the off-side rear wing – UK only, The centre console was finished in trim colour.

Dave Heinz and Dave Yarborough won The Cannonball Run, a road race across America Darien, Connecticut to LA. The Cannonball Run was a “race” that was less well publicised. The event commemorated the great American marathon driver, E.G “Cannonball” Baker whose set a transcontinental record in 1933 at an average speed of 60mph (97km/h) in a Graham Eight. Such races were almost certainly illegal then, but in the age of safety and emission laws, they were positively criminal. This did not deter 46 starters from leaving New York on the 1979 run, with 42 of them making it to Los Angeles. The winning car was an XJ-S whose drivers Dave Heinz and Dave Yarborough were lucky enough to dodge the police cars and completed the race in just 32 hours and 51 minutes which was an average of 87.25mph (140.4km/h).

December

At the end of 1978 for the 1979 model year, the decision was taken to delete the four-speed manual gearbox option. The last XJ-S model with manual transmission was dispatched during January 1979. Jaguar could no longer claim to making a car capable of reaching 150mph (241.4km/h) as the automatic transmission model could only reach 145mph. From launch to 1979 the company produced 352 XJ-S cars with the manual gearbox.

In December 1979, the new Lucas/Bosch P-digital electronic fuel injection system was introduced, which slightly improved fuel consumption and bhp. This was identified by a round single fuel rail.