Compare the Fiat X1/9 1.5 8V - [1982] vs Peugeot 504 1.8 8v - [1968]. 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 Fiat X1/9 1.5 8V or the Peugeot 504 1.8 8v. We'll leave it up to you to decide which is your favourite.