Even with truck sales way down and fuel prices way up, General Motors will continue to invest in its heavy-duty pickups to keep up with changing federal regulations and competitors. Here are the first pictures of a 2010 GMC Sierra 2500 Duramax diesel test mule.
The current Sierra HD (and its twin, the Chevrolet Silverado HD) first went on sale about 18 months ago, but GM is giving the truck a mild facelift that hints at major revisions under the hood. The grille in these photos is temporary, cribbed from a current light-duty GMC Sierra 1500, but the revised front bumper is production intent. GM softened the huge metal flares at the corners of the 2009 Silverado/Sierra HD's bumper by topping off the uppermost portion with plastic from end to end for 2010.
Pay special attention to the inlet in the middle of the front bumper, which feeds air to the truck's transmission oil cooler. It's about one third larger than the current inlet, and it makes us wonder what changes GM plans for the Silverado/Sierra's Allison transmission.
The Allison gearbox is mated to the 6.6-liter Duramax diesel engine, which will be overhauled to meet tough new EPA rules for nitrogen oxide (NOx) emissions that go into effect on January 1, 2010. The bigger inlet could mean the next-gen Duramax will require extra air for a new exhaust gas recirculation (EGR) system, which reduces NOx, but GM has officially stated 2010 Duramax NOx emissions will be scrubbed using urea selective catalytic reduction. Using urea SCR should require a less complex EGR system.
Are GM and Allison planning to add extra gears to the current six-speed Silverado for improved fuel economy and towing efficiency? Could we see the Allison transmission get eight cogs, like some luxury cars have? Or could it possibly take the leap to 12, like some big rigs use? (Twelve gears isn't as hard as some might think: A gear splitter could be added between the back of the transmission and driveshaft or transfer case, depending on whether the truck was 2WD or 4WD. The bottom line, though, is that extra gears would likely require improved airflow to the transmission oil cooler, and thus a bigger inlet in the front bumper.) That's just speculation, of course.
Extra gears also could allow the Silverado/Sierra to one-up new heavy-duty pickups from Dodge and Ford, expected to arrive by 2010 and 2011, respectively. The 2011 Ford Super Duty will feature a new 6.7-liter Scorpion V-8 diesel engine and six-speed transmission.
Check out the 2008 November/December Issue to see the full photos!