Jaguar Xj6 made its first entrance in the market in September 1968 as a sedan make. Several changes were undergone by the vehicle in the next years to cope with the shifts in demands of the times which paved way to the generation of three Jaguar Xj6 series. The first series sold like hot pancakes in the market which resulted to problem in demands. Teo engines are available, the 4,235cc DOHC I-6 with a capacity of 173bhp @ 4,750rpm and 227lb/ft @ 3,000rpm and the 2,792cc DOHC I-6 rated at 140bhp @ 5,150rpm and 150lb/ft @ 4,250rpm. Optional four speed manual with overdrive can be paired with any of the engines together with a Borg Warner three speed automatic.

The second generation was marketed in the year 1973. Although little changes were done, buyers and enthusiasts still flood along to get their hands on the car's steering wheel. Most changes were focused on the exteriors to meet the strict regulations of the US government. The bumpers were raised together with few technical enhancements of the front area of the car which is an advantage since a more muscular look was achieved. The 2,792cc DOHC I-6 was replaced with the 3,442cc DOHC I-6 engine now rated at 160bhp @ 5,000rpm and 189lb/ft @ 3,500rpm.

Major enhancements were inculcated by the third generation of jaguar XJ6 through the aid of the great Italian stylist Pininfarina. New style is evident although some features have subtle effects which can also be known once the car's power is turned on. The new models are equipped with standard fuel injection system and other advance mechanisms. Other traditional features were retained including the classic fold-down burl walnut picnic tables. The dimension of the four door makes was then 3.2 inches shorter, 9.3 inches wider, and 1.5 inches taller. Each year production for the third series also faced several changes.