Compare the Ford Sierra RS 500 - [1987] vs Mercedes E Class 500 W124 - [1990]. 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 Ford Sierra RS 500 or the Mercedes E Class 500 W124. We'll leave it up to you to decide which is your favourite.