Still think a 4-cylinder turbodiesel under 3-litre is not enought to get the job done? It's time to review some concepts...
Alongside its regular cash-transit vans built around medium-duty truck frames, Brazilian branch of the Brink's company also operates with some Argentinian-made Mercedes-Benz Sprinter vans, mostly due to their enhanced maneuverability in tight spaces, fuel savings, and to circumvent restrictions on the circulation of trucks in some areas. The only engines officially available for the Sprinter in Brazil since its introduction in '97 have been 4-cylinder turbodiesels, and this one specifically is fitted with a 2.1L OM611 rated at 127hp (129cv for those more used to the French unit, or 95kW) at 3800RPM and 300Nm. (220lb.ft.) at 1600-2400RPM backed by a 5-speed manual transmission. Apart from a handful "executive" passenger vans which featured a 5-speed automated-manual transmission, the Sprinter is only available in Brazil with manual transmissions.
Sure the weight added by the up-armoring decreases its payload in a significant matter, but it still does what it's expected to do.