Issue link: http://read.dmtmag.com/i/655335
12 l FIRST CLASSCLASS never going to happen," says Vander Pol. "We'd been running other brands for a long time. But the smaller block of the MX-11 and what it could do was interesting to us. When they offered a demo, we decided to give it a try." In the early parts of the 18-month- long trial, the MX-11-powered Model 579s were not assigned a full workload, and Vander Pol wasn't sure that would ever happen. "We just didn't know how reliable they were going to be," he says. PACCAR engine officials wanted to experiment with different software con- figurations and repeatable workloads to get the data feedback they needed to receive. But it didn't take long for the MX-11s to prove their merit and earn an increased workload. "We didn't expect to put them into full-time usage so quickly, but now we really rely on them to do their jobs," he says. "And we had actually planned on keeping them only on Portland runs, where they wouldn't go into the moun- tains. But now we've got two of them going over Snoquomie Pass every night. That's a pretty good haul." Even on "a pretty good haul," the MX-11s paired with a Model 579 are topping the fleet in fuel economy, aver- aging 6.5 mpg while the rest of the fleet gets about 6.2. "That's pretty huge," says Vander Pol. "That's a credit to that engine." FC Significant weight savings Weight savings of about 400 lbs. vs. a comparable 13-liter engine is also a bonus, even if it doesn't necessarily translate to added payload in an LTL application. "Four hundred pounds is significant, even if we don't typically gross out," Vander Pol says. "That helps with fuel economy and tire wear, with 400 lbs. less weight on the steer tires. And it sure helps not to have that extra weight when going up a hill." Drivers also weighed in on the new engine, which was set to the upper lev- els of its horsepower and torque ranges up to 430 hp and 1,550 ft.-lbs. for the trial. "I spoke to every driver who's driv- en it and they all told me it pulls just fine," Vander Pol says. "To be honest, I was quite surprised that we'd get that response, given the smaller block. But the drivers love them." One driver's response was particu- larly telling. "We have a driver who's been with us 30 years," Vander Pol says. "He's our most consistently performing driv- er. We had him in one of these trucks, going through the mountains, and he came back and said, 'This works great.' "That's all we needed to know." Each of the trucks has tallied more than 150,000 miles. According to Vander Pol, the performance of the Model 579s and MX-11s did lead to one breakthrough for the company. Peterbilts finally made their debut in the city-truck side of the fleet last spring when Oak Harbor purchased four Model 337s powered by PACCAR PX-7 Engines. "After seeing this new engine per- form, the door is definitely open for more Peterbilt trucks and PACCAR engines to work their way into our fleet," says Vander Pol. Director of Maintenance Dan Vander Pol (left) says the MX-11 Engine paired with a Peterbilt Model 579 has made a significant impression in trial performances at Oak Harbor Freight Lines.