Despite the benefits there are issues with I6 too and the most pronounced amongst these is packaging. An I6 engine will always be longer than an equivalent capacity V6 and for those brands offering front-wheel drive luxury cars, that makes them nearly impossible to fit transversely and accommodate a gearbox. Mercedes is in the fortunate position of primarily producing rear-wheel drive configuration vehicles, but although this solves the issue of engine/gearbox packaging with a longitudinal layout, it creates a crash safety problem all of its own. Ensuring frontal impact pedestrian safety compliance requires a larger margin between the longitudinal in-line engine’s forward mounting points and the grille/bonnet energy deformation zone, enforcing a longer bonnet structure. Preventing the longitudinally mounted engine from puncturing the cabin during a severe impact is a secondary crash safety challenge with any I6, but Mercedes assures us that engineering solutions have been secured for all these issues.