WESTLAKE VILLAGE, CA – As manufacturers of heavy-duty truck engines strive to meet government-regulated emission standards by implementing new emission technologies, customers are increasingly experiencing problems with their engines, according to the J.D. Power and Associates 2006 Heavy-Duty Truck Engine/Transmission Study.

The study, now in its 10th year, measures customer satisfaction with the engines in two-year-old heavy-duty trucks (Class 8) by examining four vital engine factors. They are (in order of importance): engine quality (30%); engine performance (26%); engine cost of ownership (22%); and engine warranty (22%). The study examines engines supplied in 2004-model-year trucks, the second model year impacted by the Consent Decree that raised diesel engine emission standards.

To meet emission regulations, manufacturers are continuously redesigning engines and employing new technologies, such as redirecting exhaust gas back into the engine to burn off more pollutants. Consequently, the average number of reported engine problems has increased to 74 PP100 (engine problems per 100 vehicles), up from 46 PP100 in 2005, according to the J.D. Power and Associates study.

For the sixth year, a Caterpillar engine ranks highest in the vocational segment. The Caterpillar C-12 ranks highest among vocational heavy-duty truck engine models, performing particularly well in three of the four factors that determine overall satisfaction: engine quality, performance, and cost of ownership. The Caterpillar C-15 follows the C-12 in the rankings.

The study also finds that among the four drivers of engine satisfaction, customers are least satisfied with the cost of ownership, particularly in the areas of routine engine maintenance costs and fuel efficiency. Reported fuel consumption for heavy-duty engines has declined to 5.72 mpg in 2006-down from 5.91 mpg in 2005 and 6.04 mpg in 2004.

The 2006 Heavy-Duty Truck Engine/Transmission Study is based on the responses of 2,529 primary maintainers of two-year-old heavy-duty trucks (Class 8).