Compare the Bentley Mulsanne Speed 6.8 V8 Turbo - [2014] vs Renault Megane RS 1.8 Turbo 300 Trophy - [2018]. 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 Bentley Mulsanne Speed 6.8 V8 Turbo or the Renault Megane RS 1.8 Turbo 300 Trophy. We'll leave it up to you to decide which is your favourite.