Paccar unveils new MX engine

MOUNT VERNON, Wash. — Kenworth and Peterbilt customers now have a new, high-tech engine choice in parent company Paccar’s MX diesel.

Paccar took the wraps off the North American-spec’ MX at its Mount Vernon, Washington Technical Centre on Feb. 4, inviting media in from all over North America for the occasion. The introduction came after a successful 80 million kilometre test program in which the company says the MX performed up to expectations for power, efficiency and cleanliness.

Paccar says the MX offers best-in-class performance, economy and, according to chairman and CEO Mark Pigott, is one more step forward in the company’s plan to offer its own complete powertrain solution.

Pigott says that, while the launch of any new product is a momentous occasion, “This introduction is even more so because it’s occurring as our industry continues to confront the worst recession in decades.”

He points to the realities of aging fleets that will need to be replaced and low dealer inventories of new and used trucks as positive signs for the industry.

“The good news,” Pigott says, “is that Paccar is in an excellent position to grow when the economy improves.”

The Paccar boss says the company invested a billion dollars into its engine program over the past decade and has delivered an entire family of engines, two new engine factories, expanded engine test facilities and “the best engine development team in the business.”

A clean sheet design, the MX is a 12.9-litre, inline six-cylinder turbo diesel with four valves per cylinder and an in-block cam design that not only allows it to be mounted lower, reducing vibration characteristics, but which also reduces its complexity thanks to fewer moving parts.

“Our goal,” says Paccar president Jim Cardillo, “was to offer the lowest cost of ownership for Kenworth and Peterbilt customers and we think we’ve achieved that.”

He cites what he says is the MX’s best-in-class fuel economy and drivability, torque-to-weight ratio and easy access for maintenance.

The MX engine can be configured to put out from 380 to 485 horsepower and up to 1,750 lb.-ft. of torque, which the company says puts it at the upper end of the power/torque range for Class 8 applications. Part of its efficiency, Cardillo says, comes from the use of CGI (compacted graphic iron), which he says is 75% stronger and stiffer pound-for-pound than gray cast iron. Paccar, Cardillo says, was first to use CGI for the cylinder head and is the only manufacturer to use it for both the engine block and the head.

Using CGI shaves about 150 lbs from the weight, according to Craig Brewster, Paccar assistant vice-president, while a crankshaft design that eliminates counterweights saves about 25 more pounds. The result is an engine that tips the scales at about 325 lbs less than the Cummins ISX.

The design and construction of the block and rear gear train also contributes to significantly lower in-cab noise levels, Brewster says, “resulting in a more comfortable driver environment.”

Paccar claims a noise level for the MX that’s three times more quiet at idle and about 1.5 times quieter at 88 and 113 km/h (55 and 70 mph).

That quiet performance was noticeable during a test drive session the company offered journalists, who were invited to take a couple of laps around the Technical Center’s 1.5-mile high-speed oval and 1.5-mile durability track. The MX engine-equipped trucks were indeed quiet, making conversation easy at speeds up to about 105 km/h.

“You can lower the radio volume by half,” Brewster says, noting that “when we heard that from our test drivers, we knew we were on the right track.

The MX engine also uses fractured cap technology for the main crankshaft bearing, which Cardillo says results in increased strength and contributes to longer power and torque curves across a wide range of RPMs.

Brewster says the flat torque curve gives the MX a more responsive feel and excellent drivability while helping reduce downshifting under load. He also says its integral engine brake (rated at an industry-leading 460 hp at 2,200 RPM) provides powerful performance across a broad range of engine RPMs.

The extensive testing of the MX engine for the North American market included some 300,000 hours of extreme lab testing at Paccar’s Mount Vernon Technical Center, where they can simulate a variety of driving and environmental conditions. The MX also underwent winter testing near Yellowknife, extreme heat tests in Death Valley, California and the Arizona desert and high altitude tests above 3,000 metres in the Rocky Mountains of Colorado.

This real world testing was helped by Paccar customers who drove the MX in their day-to-day operations, with data-linked trucks sending information to the Paccar Technical Center for analysis. The engines were also run at the Technical Center using data gleaned from the real world trials.

The commitment to design and manufacturing excellence should contribute to a long-lived engine:  Paccar claims a B10 engine life for the MX, which means 90% of the engines will reach a million miles of service as compared, they say, with their competition’s 50% rate.

Though new to North America, the MX has been powering Paccar’s DAF trucks for about four years. And of course it’s only the latest in a series of engines the company has cranked out over the past 50 years. “We’ve delivered more than 900,000 engines to date,” says Cardillo, “and have 125,000 MX engines in service (outside North America) already. It’s reliable, quiet, and fuel-efficient.”

It also appears to be building a reputation.  Paccar says, for example, that the MX was named “Best Engine of the Year” three years running at the Bus World Asia Exhibition in China.

The MX meets EPA2010 diesel engine emissions rules using Selective Catalytic Reduction (SCR) in combination with exhaust gas recirculation (EGR). Diesel Exhaust Fluid (DEF) tanks can be ordered in sizes from six to 30 gallons and mounted on either side of the truck.

According to Alan Treasure, Paccar’s director of marketing, each MX-equipped vehicle will have a DEF gauge on the dash to provide easy-to-see-and-understand indication of the DEF level. 

“In the event the DEF fluid levels drops below 10% fill level,” Treasure says, “there will be a series of progressive indicators to alert the driver of the condition, from a warning light on the DEF gauge to an illuminated check engine light, and to an illuminated stop engine lamp.”

Treasure says the warnings are designed to alert the driver of the DEF level and provide sufficient time to take action.

The engine will be produced in North America at a brand new, $400-million plant near Columbus, Mississippi. Ground was broken for the plant in 2007, with construction finished last year. Engines are expected to begin flowing from the facility this summer, initially via reconfigured European-built engines, with US domestic production to follow.

Paccar is already taking orders for the MX through its Kenworth and Peterbilt dealer network. It comes with a two-year, 250,000-mile standard warranty, with extended service plans available.

So far as pricing is concerned, Paccar will only say that it will be competitive, slightly less than a 15-litre but offering all the same features.

Paccar is confident its commitment to engine production and faith in the future will help the MX earn its place in the transportation industry.

“Not many people have built factories in North America in the last 18 to 24 months, but we did,” says Cardillo. “We’re in the engine business in North America, and we’re proud to be here.”

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