November was a strong truck sales month for Ford and Chrysler, with sales up 17.9 and 23 percent respectively for the F-Series and Ram. The Chevrolet Silverado and GMC Sierra were down 10.4 percent and 2.0 percent for the same period. The slow sales performance has swelled GM's truck inventory to 245,853 units, or a 139-day supply.

However, GM executives were quick to point out that rivals strong sales for the month were likely largely driven by generous incentive spending. The other factor in play is that the bulk of sales for Ford and Chrysler were on 2012 model trucks, whereas most of GM's sales were the 2013 models. GM introduced its 2013 models 45 days early, and deliberately ramped up production of 2013 models in anticipation of a planned temporary shutdown and retooling for the highly anticipated 2014 Chevrolet Silverado and GMC Sierra models.

By holding back on big incentive spending, GM's average transaction price on trucks rose more than $2700 over the same period last year.

Source: Automotive News