All 2006 Chassis Sprinters (and earlier) which are generally 2007 and earlier coaches, are the T1N chassis, which is a 2.7L 5 cyl diesel. You can spot these by the air louver on the hood, a single wide black louver. All in North America will be either Dodge or Freightliner Grill and markings. (A number of owners of these NAFTA version Sprinters have changed the grill and badging to Mercedes, but none were marketed this way new in North America.)
Beginning with 2007 chassis (known as NCV3) a 3.0L v6 Diesel is used and is identified by the two separate air inlets on the hood. A few 2008 Winnebagos were put on 3.5L v6 gasoline engine Sprinter chassis, and more recently a few were built on a 2.0L 4 cyl diesel chassis.
All will have the same basic 5 spd automatic transmission except the 4 cyl model, which has a 7 speed transmission.
About 2012 chassis model, Mercedes took the line away from Dodge as they sold Chrysler off to a group of investors, after this changeover the chassis is badged either Mercedes or Freightliner (which is a Mercedes subsidiary).
Maintenance on this chassis is somewhat quirky and owners need to be careful to use fluids and lubricants approved by Mercedes Benz for the particular application. V6 in particular are demanding, using only certain oils, of which there are only a few in the US meeting the spec, this is to avoid damage to the diesel exhaust filter system.
Also, join the Sprinter Forum to learn about the models of Sprinter you are looking at. There are different forums for the NCV3 and the T1N and also sub forums for the motorhomes, and write up forums with stuff on oil changes, trans fluid changes, etc.
http://sprinter-source.com/forum/index.php
Charles
'03 Ram 2500 CTD, 5.9HO six speed, PacBrake Exh Brake, std cab, long bed, Leer top and 2008 Bigfoot 25B21RB.. previously (both gone) 2008 Thor/Dutchman Freedom Spirit 180 & 2007 Winnebago View 23H Motorhome.