When they introduced it in the mid-70s, the XJS was a big step for the company. Under the long hood, there was the famous 3.6-liter six-cylinder or a 5.3-liter V12 engine, which was a better choice if you wanted the full GT experience. The XJS was an extremely popular choice, especially in America where Jaguar sold the majority of the 115,000 cars they made.
Due to its elegance, power and speed, the XJS remained in production for an incredible 21 years. In fact, it is still a respectable car in every way. However, the V12 was somewhat unreliable, while the straight-six was underpowered. So, what to do? Just install a thumping big V8 to enjoy this elegant Brit with a U.S. accent.