SLKFORTWO
Active Member
Haven't driven the 5 litre engine but in the R171 SLK the 350 is very quick, free-reving and remarkably frugal engine. EG Last night (following AC/DC concert), NEC to home in Bristol 1hr 15mins, 29.8 mpg. Going to the show and taking about 20 mins or so longer 33.5 mpg. Cant see a V8 getting near those sort of consumption figures. However the only way to be sure which one is right for you is to drive both. Good luck!