Owners Less Satisfied with Heavy-Truck Engines

The technology required to meet U.S. diesel emission standards is causing more engine problems and less owner satisfaction among Class 8 truck owners, according to J.D. Power and Associates.

Power's Heavy-Duty Truck Engine and Transmission Study says 47% of heavy-truck owners report engine problems with their year-old vehicles compared with 42% in last year's survey. One in four with engine problems blames electronic control module calibration; one in five cites the exhaust gas recirculation valve.

Power says the average number of engine- and fuel-related problems per 100 vehicles rose to 81 this year from 71 in 2011. Overall engine satisfaction slipped to 719 from 739 out of a possible 1,000 points.

Owners are less satisfied with their trucks' transmissions too. The average rating dropped eight points to 812 this year, although transmission quality improved to seven problems per 100 units from 10 problems in 2011.

Among the six diesel engine brands, Detroit (formerly Detroit Diesel) ranked best, followed by Caterpillar, Volvo, PACCAR, Mack and Navistar.

The 16-year-old Power survey determines satisfaction in eight areas: electronic control modules, access to service and maintenance components, vibration at idle, fuel economy, ability to maintain speed on grades and engine reliability/dependability, warranty and acceleration under full load.