Compare the Iso Grifo GL 300 5.4L V8 - [1965] vs BMW 5 Series M5 E28 - [1985]. 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 Iso Grifo GL 300 5.4L V8 or the BMW 5 Series M5 E28. We'll leave it up to you to decide which is your favourite.