An improved outlook for U.S. demand is boosting a WardsAuto forecast of 2013 North American light-vehicle production by more than a quarter-million units.

However, the gains resulting from the February revisions are not evenly distributed by manufacturer or segment.

Chrysler, General Motors, Honda, Nissan and Volkswagen are the major beneficiaries among manufacturers, and a good portion of the increase is coming in large pickups and cross/utility vehicles, although some car segments also show significant gains.

The hike in expected production of 255,000 units puts 2013 at 15.88 million LVs for the year, up 3.2% from 15.38 million in 2012.

Driving the higher production forecast is an increase in WardsAuto’s overall LV sales outlook, pushed up by some 300,000 units to 15.3 million, as well as some fine-tuning in demand at the vehicle-line level.

With this momentum expected to continue into 2014, WardsAuto also is increasing its LV production forecast for 2014, up 189,500 units to 16.51 million, 3.9% above 2013.

Among manufacturers, about 40% of the added volume in 2013 and 2014 occurs at Chrysler, mainly due to increases in Ram pickup production and midsize-car output at the auto maker’s Sterling Heights, MI, plant.

Nissan also accounts for a large share of the hike, mostly as a result of a significant upward revision for its new Tennessee-built Nissan Pathfinder large CUV, which replaced the previous-generation truck-based SUV at the end of last year.

Significant increases have been made in General Motors’ production ledger for 2013, due to higher-than-expected output of GMT900 pickups at Flint, MI, and Silao, Mexico. Despite recent high inventories and sluggish sales, production of Chevrolet Malibu sedans has been boosted slightly at the Hamtramck, MI, plant.

In addition to an increase in the demand outlook for large pickups, some of the added output at Flint is the result of a delay in the changeover to the redesigned versions of the Chevrolet Silverado and GMC Sierra. The production start for the new models there has been pushed back to January 2014 from September 2013.

Output of the re-engineered GMT900 pickups is slated to begin in May in Silao, and in July at the Ft. Wayne, IN, plant. As part of the changeover, the forecast calls for Silao to permanently cease production of the Cadillac EXT and Chevrolet Avalanche at the end of March.

Along with the pickups, redesigned versions of GM’s large SUVs built on the same fullsize-truck platform in Arlington, TX, start production next year with launches of the five vehicles built there spread throughout the first quarter.

Honda also accounts for some of the gains in the 2013 and 2014 forecasts, with increases made to the Honda Civic at Alliston No.2 in Ontario, Canada, and Greensburg, IN, and to the Accord in Marysville, OH.

Production of all large pickups has been increased about 81,000 units for 2013 and by 47,000 in 2014. In addition to Chrysler and GM models, output of Ford’s F-150 and SuperDuty pickups and the Toyota Tundra has been boosted slightly. Production of the Nissan Titan, scheduled for a redo next year, has been pared.

Output of large CUVs has been hiked by 64,000 units for 2013 and 53,000 in 2014, mostly due to the Pathfinder, but also from upticks by the Chevrolet Traverse and GMC Acadia, built on GM’s Lambda platform.

An increase of 47,000 units in production of Upper Small cars was due to higher output for the Civic, Nissan Sentra and Volkswagen Jetta.

Increases to the forecast for Chevrolet Impala, Malibu, Dodge Avenger and Accord builds in 2013 more than offset a cut to the Toyota Camry, for a net gain of 41,000 units to the Upper Middle car segment.

A redesigned Impala starts production in March at the Oshawa No.1 plant, in Ontario, and in April at the Hamtramck plant. The current-generation Impala remains in the mix at Oshawa No.2 until July 2014.

The reduction in the Camry is due to increases to its stable mate, the Lower Luxury Toyota Avalon, re-engineered late last year.