The e400mmc is a 6.7 litre Cummins unit
The StreetDecker is a 5.1 litre Merc/Daimler unit
Therefore the streetdecker has to be pushed much harder than the E400 therefore the engine would wear out much faster.
Would flogging a small engine be more economical than cruising with a big engine, I doubt it. And in the long term the e400mmc would surely more financially viable
RE: Go North East: Latest News & Discussion - July 2015