Photos by Chris Doane Automotive
Our spies are everywhere, even places you wouldn't expect to find much information. In fact, during a recent catch of a fleet of various heavy-duty GM trucks being tested in Michigan (similar to those spied a few weeks ago, our shooter noted some multistate plating that could mean there are some additional powertrain alliances coming or more significant changes in store.
In the past, catching a camouflaged pickup truck with Indiana plates (usually a Ram HD) meant that Cummins was testing (its headquarters are in Columbus). What's unique in these photos is that the exhaust tips show two different types of tailpipe tips (see below). Yes, they both have the open venturi flange to help cool exiting exhaust temperatures, but the Michigan-plated truck is a little different.
The bottom Indiana-plated truck has the conventional-looking Duramax tailpipe, while the top one has a more custom-welded "straight-pipe" look and what looks like an added sensor on the rear differential drain plug, presumably for keeping track of oil temperature. We should also note that Allison Transmissions has a facility near Indianapolis and could be testing a stronger, heavier-duty transmission for the next-generation HD trucks that some are saying will be out in 2015.