LOUISVILLE, Ky. — Paccar announced at the Mid-America Trucking Show that it has deployed more than 20,000 trucks with its own MX engines, with a current backlog of another 6,000 units in the pipeline.

“And we expect that number to continue to expand in 2012,” said Gary Moore, Kenworth general manager and Paccar vice-president. “It’s steadily becoming a greater portion of Kenworth’s build.”

Paccar also announced its Kenworth and Peterbilt trucks are coming off record years and looking to build on their growth.

Moore said Kenworth achieved a record 14.1% Class 8 market share in 2011 and had reached 15.8% so far in 2012. The new T680 rounds out Kenworth’s highway truck lineup, with a cab width that compliments the narrower T660 and ultra-wide T700.

Bill Kozek, general manager of Peterbilt Motors, said Peterbilt enjoyed one of the best years in its 73-year history in 2011. It, too, reached a new record for Class 8 market share, ramped up capacity to unprecedented build rates at its Denton, Texas plant and hired more than 1,000 people. It also added 11 dealers to its network.

Kozek predicted a 20% increasein Class 8 truck demand in the North American market this year, reaching between 215,000 and 240,000 units, possibly making 2012 the fourth best year in North American Class 8 market history. He also noted the medium-duty Classes 6-7 markets are poised to grow in demand by 20-40% this year.

Like many OEMs, Peterbilt has identified natural gas as a potential growth market. Robert Woodall, director of sales and marketing, said Peterbilt intends to sell more than 2,000 natural gas-powered trucks in 2012 and currently offers seven different configurations with more to come.