Compare the Mercedes GT R AMG Coupe 4.0 V8 Bi Turbo - [2018] vs Dodge Challenger SRT Hellcat 6.2 V8 - [2017]. 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 Mercedes GT R AMG Coupe 4.0 V8 Bi Turbo or the Dodge Challenger SRT Hellcat 6.2 V8. We'll leave it up to you to decide which is your favourite.