Compare the Jaguar XJ 12 5.3 - [1972] vs Saab 900 2.0 Turbo 16v S - [1984]. Find out which car is the fastest, most powerful, lightest or has the biggest engine in our top trumps style comparison page. Find out which car has the highest top speed or is the fastest accelerating, is it the Jaguar XJ 12 5.3 or the Saab 900 2.0 Turbo 16v S. We'll leave it up to you to decide which is your favourite.