DaimlerChrysler’s Chrysler Group made the biggest gain in North American manufacturing efficiency last year, passing Ford for the first time in a closely watched study of automotive productivity.

The Associated Press (AP) said Chrysler, the smallest of Detroit’s ‘Big Three’ carmakers, improved overall productivity by 7.8% from 2002 to 2003, the second consecutive year it made the biggest jump in the report released on Thursday by Harbour Consulting – last year, Chrysler posted an 8.3% improvement.

The Harbour Report, published since 1989, tracks how many hours it takes to build a new car or truck – company by company, plant by plant, the report noted.

In overall productivity, which includes assembly, stamping and powertrain operations in North America, General Motors was on top at 35.20 hours per vehicle, followed by Chrysler at 37.42 and Ford at 38.60 – Honda, Nissan and Toyota submitted limited reports and were not included in the overall rankings, AP said.

According to the news agency, GM improved its overall ranking 5.2% last year, contributing to a 25% improvement in the past six years, while Ford’s overall gain was 3.4% in 2003.

“Manufacturers that are using disciplined, common processes to drive consistent, sustainable improvement are seeing the most progress in the report’s measures,” Ron Harbour, president of Troy-based Harbour Consulting, told the Associated Press.

New United Motoring Manufacturing, the joint venture between GM and Toyota in Fremont, California, led the overall assembly rankings at 21.92 hours per vehicle, next was GM’s lone operations at 23.61 hours per vehicle, Mitsubishi at 25.43, Ford at 25.44 and Chrysler at 26.01, the report said.

Among individual plants, Nissan’s Smyrna, Tennessee, factory that produces the Altima ranked at the top of the list at 15.33 hours per vehicle, establishing a new industry standard – Smyrna broke its own mark of 15.74 set last year, according to AP.

The report said that GM’s two plants in Oshawa, Ontario, finished second and third at 16.40 and 17.03 hours per vehicle, and its two plants in Lansing were fourth and fifth, while Ford’s Chicago plant was sixth and its Atlanta plant was seventh – no Chrysler plants finished in the top 10.

“We’re very pleased with the consistent progress we continue to see in our manufacturing productivity,” Guy Briggs, GM’s group vice president for manufacturing and labour relations, told the Associated Press, adding: “However, significant cost issues like out of control health care expenses will not allow us to rest on these accomplishments.”