The diesel engine option is now available for purchase with the 2014 Ram ProMaster full-size van in addition to the standard V-6 gasoline power plant.

The ProMaster arrives with a standard 3.6L DOHC V-6. A 3.0L inline-four EcoDiesel engine is available as an optional engine. Ram pairs both engines with a six-speed automatic transmission.

Ram offered the gasoline engine at launch when it began selling the van at the end of 2013; the diesel engine became available at the end of June. The diesel engine is available with the ProMaster 1500, 2500, and 3500 with cargo and passenger models. The EcoDiesel is also available with the chassis cab and cutaway.

The EcoDiesel available with the ProMaster is different than the 3.0L V-6 EcoDiesel offered with the Ram 1500 EcoDiesel pickup truck, said Mark Mallie, Ram's head of chassis cab/commercial product planning.

The 2014 Ram ProMaster 2500 with the EcoDiesel, 136-inch wheelbase, and high roof starts at $31,520.