General Motors Company (GM 4.76%) released redesigned versions of its popular Chevy Silverado and GMC Sierra trucks in 2013. The new full-size truck models had an immediate impact on GM's profitability, as the new trucks have commanded higher average transaction prices than the previous generation.

GM has achieved high average transaction prices with its new pickup trucks. Source: General Motors Company.

However, from a market-share perspective, GM struggled following the launch of its new trucks. As GM worked to raise transaction prices, cost-conscious truck buyers looked elsewhere. However, GM's growth in the full-size truck market has accelerated in recent months. It appears to be seizing the opportunity created by Ford's (F 0.31%) F-150 model changeover.

General Motors gives up some market share
In 2013, Chevy Silverado sales rose 14.8% and GMC Sierra sales rose 17.3%. It was a tale of two halves, though. In the first six months of 2013, combined Silverado and Sierra sales rose 23.5%. By contrast, in the second half of the year, combined Silverado and Sierra sales rose by only 8.6%.

GM's slow growth in the full-size truck segment continued into 2014. Through July 2014, combined sales of the Chevy Silverado and GMC Sierra rose less than 1% year over year. Ford F-150 sales were also around the flat line through July (up 0.3%), but Fiat Chrysler was the big market share winner. Ram pickup sales rose 19% year over year for the first seven months of 2014.

Truck sales are bouncing back
Since July, GM's pickups have made a strong comeback. In the August-November period, combined Silverado and Sierra sales have risen 24% year over year. November was a particularly strong month for GM in the full-size truck market, as combined Silverado and Sierra sales soared 34%. (Admittedly, November 2013 was a weak sales month.)

Chevy Silverado sales have surged in the last few months. Source: General Motors Company.

GM is finally taking advantage of the dislocation at top rival Ford, which just began mass production of the redesigned 2015 Ford F-150. Earlier this year, Ford estimated it would lose about 90,000 units of F-150 production in 2014 because of shutdowns needed for retooling its truck plants.

A good deal of this shutdown time occurred this fall, and it showed in Ford's November truck sales numbers. Ford's F-Series truck sales had been down just 0.5% year over year through the first 10 months of 2014, but U.S. F-Series sales dropped 9.9%, to 59,049, last month.

A window of opportunity remains
General Motors still has a meaningful window of opportunity to gain share in the full-size truck segment before it faces the full competitive impact of the new F-150. Thus far, Ford has only completed the production changeover at one of its two truck plants. The other changeover will occur in Q1 2015.

Ford's changeover to production of the new F-150 is limiting its truck sales. Source: Ford Motor Company.

This means Ford could have as much as nine weeks of F-Series plant downtime next quarter. This would knock out tens of thousands of units of production yet again. As a result, Ford is likely to be supply constrained for F-Series trucks well into 2015, giving GM a chance to gain more market share while protecting its high average transaction prices.

The General is poised for profit growth
GM's rebounding fortunes in the full-size truck market -- along with other positive drivers -- have already begun to boost its profitability. Last quarter, GM's adjusted pre-tax income in North America rose 12% year over year to $2.45 billion, despite $100 million of incremental recall expense.

General Motors will face easy comparisons and lower competition from Ford in the full-size truck market through the first half of 2015. That should allow GM to continue growing sales without offering big discounts in what is already a high-margin segment. This could be a significant windfall for GM in 2015, helping the company post strong earnings growth.