Fleet Reviews Mixed in ’07 Engine Tests
This story appears in the Feb. 22 print edition of Transport Topics. Click here to subscribe today.
TAMPA, Fla. — Some of America’s largest fleets reported general acceptance of the 2007 generation of diesel engines, although some said they had difficulties and higher expenses with them, in assessments offered during the annual meeting of the Technology & Maintenance Council here recently.
The engine report card discussion included remarks from refrigerated carrier TransAm Trucking Inc., whose representative said it had purchased nearly 1,000 trucks with Caterpillar C15s and after racking up 120.4 million miles, labeled them “unacceptable.”
TMC, a division of American Trucking Associations, surveyed 120 of its fleet members and said that, on average, the responses divided evenly between those saying the pre-2007 engines were better and those saying the newer power plants were either as good or better than the earlier models.
The three largest fleets to present results were YRC Worldwide Inc. and FedEx Freight, North America’s two largest less-than-truckload carriers, and Schneider National Inc., the largest truckload carrier.
The changes in emissions standards set by the U.S. Environmental Protection Agency from January 2007 through the end of last year resulted in the introduction of diesel particulate filters, ultra-low-sulfur-diesel fuel, and a new, low-ash engine oil known as CJ-4.
Of the four presenting companies, FedEx Freight bought the most vehicles, acquiring 2,369 tractors with Cummins ISX engines, said company project manager Curtis Cummings. After they accumulated 378 million miles, he reported improved miles per gallon, lower costs per mile and no change in preventive maintenance intervals, compared with pre-2007 models.
However, he also said the carrier had to clean more than 100 DPFs because of aftertreatment injector plugging, and he said exhaust gas recirculation valves remained a concern.
“Our overall experience with EPA 2007, compared with pre-2007, has been good,” Cummings concluded.
Schneider National Vice President Steve Duley, who oversees purchasing for the company, bought 1,876 trucks with 2007-vintage engines, most of them made by Detroit Diesel Corp. or its sister company, Mercedes-Benz.
Duley said drivers liked the trucks — and he gave his suppliers credit for offering solid support — but they also found a number of nagging, costly concerns. The new models generated 3% more work orders, there were defects with the DPF sensors and each DPF regeneration, occurring every 400 to 425 miles, burned about 0.9 gallon of fuel.
A related concern was a 5% loss in miles per gallon versus pre-2007 engines, Duley said.
Net maintenance costs at Schneider were higher than with pre-EGR models made before October 2002 but less than with the first EGR engines of 2003-06.
YRC bought almost 1,300 Volvo engines and about 400 Detroit Diesels, and the company found it lost some fuel economy and had to invest in more training for technicians, said Dan Miller, procurement manager.
TransAm’s Frank Nicholson, the new chairman of TMC’s engine study group, who had bought 971 Caterpillar engines, said his parts costs increased by 37% in-house and 130% on the road, and his labor costs increased by 50% in-house and 100% on the road.
Downtime increased by 125%, Nicholson said, and there have been difficulties in obtaining parts.
Caterpillar Inc. declined to comment for this story.
Nicholson also reported “condemning limits for wear metals” in the engine oil, specifically aluminum, iron and chromium, and said that Caterpillar has not been able to figure out the cause.
He said he could complain easily for another 15 minutes, but instead he offered a summary assessment of the Caterpillar engines: “Drivability has been acceptable, when you can drive it. An overall score card for our experience with the EPA 2007 engine iron is ‘Unacceptable.’ ”
