Paccar says its new heavy-duty MX diesel will be the standard engine in most Kenworth and Peterbilt Class 8 models as 2010 unfolds, and that it will be federally certified without use of emissions credits.
Initial MXs will come from Paccar's DAF subsidiary in The Netherlands, while a new plant at Columbus, Miss., will equip the engines for North American service and then begin building them this summer.

Executives said the MX, whose 2010 availability they announced in late January, will be the class leader in durability and longevity, and will be fuel efficient, lightweight and easy to service. The engine will have a B10 life of 1 million miles, meaning 90 percent of MXs should still be running after covering a million miles in over-the-road service -- about twice as far as most competitors' 13-liter-class diesels, Paccar managers claimed.

The MX is new to North America, but its development began in 2000 and DAF has built more than 125,000 for use in Europe and other markets, said Paccar's chairman and CEO, Mark Pigott. Service and parts support are already planned. More than 1,000 dealer technicians have been factory trained and certified to work on the MX, and more are being educated. Specialists in Paccar's headquarters Call Center are also trained in it.


Pigott told a group of trucking editors gathered Feb. 4 at the Paccar Technical Center at Mount Vernon, Wash., that the company invested $400 million in the new engine plant in Mississippi - "quite a commitment, since we're in the worst recession since World War II," Pigott said. It contributed $2 million to a community college to train assembly line workers, and many have gone to Holland and built engines in the DAF plant with coaching from workers there, said Lex Lemmers, former plant manager at Eindhoven who's now in charge of the Columbus factory.

The 12.9-liter (788-cubic-inch), 6-cylinder MX will be available in five ratings, from 380 horsepower and 1,450 pounds-feet to 485 horsepower and 1,650 pounds-feet. One is a muli-torque version that makes 430 horsepower and 1,550 to 1,750 pounds-feet. It has an integrated compression brake that develops as much as 460 retarding horsepower. Paccar-branded electrical accessories were designed and tested to ensure balanced performance with each other; alternator, starter and batteries are made for this engine by Denso, Mitsubishi and East Penn, respectively.

EPA 2010

To meet the federal EPA's 2010 exhaust-emissions limits and California's Clean Idle standards, the MX uses exhaust-gas recirculation, a diesel particulate filter and selective catalytic reduction, along with advanced electronic controls, high-pressure fuel injection and precision air-handling. The MX meets the federal limit of 0.2 gram per horsepower-hour of NOx without EPA-granted credits, Pigott said.

The MX's 24 exhaust and intake valves are operated by pushrods driven by a single low-mounted camshaft instead of a heavier, bulkier overhead cam, Lemmers said. In a heavy diesel, an in-block cam makes for a lower stance that's important for installation in its European cab-over-engine trucks, and contributes to clean installation under the hoods of its North American conventional-cab models.

The engine also features a single variable-nozzle turbocharger, rear-mounted timing gears, and crankshaft with no counterweights. Cylinder heads and blocks are cast of compacted graphite iron that is stronger and stiffer yet lighter in weight than common grey iron; CGI alone saves about 150 pounds over grey iron, said Jim Cardillo, Paccar's president. Stated dry weight of an MX is 2,640 pounds, 325 pounds less than the 15-liter Cummins ISX, which continues as an option in Class 8 Kenworths and Peterbilts.


The new engine widens Paccar's range of proprietary engines, joining the Cummins-built Paccar PX-6 and PX-8 midrange models for North American trucks and its own 4.5- and 9.2-liter diesels for DAF trucks in Europe. Pigott strongly hinted that DAF-made axles and gearboxes might appear later in KWs and Petes. DAF has built 125,000 MXs for Europe and other overseas markets; customers include a bus builder in China, where the MX was named Bus Engine of the Year three times.

Quietness and fast throttle response are among designed-in attributes that test drivers comment on, executives said. The MX's North American version has accumulated 50 million miles of on-road testing in Paccar and customer trucks, the latter in real-life service over the past three years. Lab and track testing has consumed some 150 million hours. Paccar invested $100 million in the latest test equipment here and at DAF's tech center in Eindhoven, Holland. Engineers in the U.S. and Europe share research and test data, and collaborate in meeting ever-stricter American and European exhaust-emissions limits.

Basic warranty is 2 years/250,000 miles, with extended warranties available. The engine comes standard with full-flow and bypass filters that allow an oil-change interval of 40,000 miles in over-the-road operations. The engine is designed for highway and vocational service.

The MX is the latest example of "quality, technology and innovation" in components, vehicles and operations that benefit its customers and shareholders, Pigott said. He noted that Kenworth and Peterbilt have been known for many years as premium trucks, that the company emphasizes sales, service and support through its independent dealers, and that Paccar has been consistently profitable, paying dividends to its stockholders for 71 consecutive years.