For the fourth year in a row, Hino Trucks USA’s engines took top honors in the J.D. Power and Associates’ 2011 U.S. Medium-Duty Truck Engine and Transmission Customer Satisfaction Study. The powerplants garnered 794 out of a possible 1,000 points based on responses from 1,037 primary maintainers of one-year-old conventional cab medium-duty trucks polled between June and August of this year.

Cummins Inc. snagged the number-two slot with 763 points, followed by Paccar with 747 points and Navistar with 742 points.

Brent Gruber, senior manager of the commercial vehicle practice at J.D. Power, said this study measured customer perceptions of 2010 model-year Class 5, 6 and 7 trucks equipped with both gasoline and diesel engines by looking at eight distinct factors: engine reliability/dependability; ease of access for service or maintenance; maintaining speed on grades; acceleration when fully loaded; control module (ECM); vibration at idle; engine warranty; and average fuel economy.

Gruber said the study discerned that medium-duty truck owners are most satisfied with engine reliability and dependability, compared with all other factors.

However, according to J.D. Power, while the incidence of engine-related problems for medium-duty trucks remains stable from 2010, averaging 39 problems per 100 (PP100) vehicles this year, there has been an overall increase in these problems over time. For example, during the past five years, the average number of problems with medium-duty truck engines has increased by 13 PP100 among trucks that have been in service for 13 to 18 months.

The study also found that competition is intensifying within the medium-duty truck industry, with the gap between the highest- and lowest-ranked brands narrowing to 53 points in 2011 from 96 points in 2010.

“With truck owners placing such importance on the quality and reliability of their engines, providing a nearly problem-free experience is a key differentiator between brands,” Gruber said, pointing out that the impact of the 2010 emission technology changes on medium-duty truck engine quality and customer satisfaction will be reflected in J.D. Power’s study next year.

He also noted that the impending emissions and fuel efficiency standards recently announced by the U.S. government will put additional pressure on engine manufacturers for the next several years.

“Whether manufacturers can reverse the steady increase in problem occurrence remains to be seen, particularly with the effects of the EPA’s 2010 mandates coming into play,” Gruber added. “Given the quality issues that arose from new emissions requirements in 2004 and 2007, the 2010 emissions standards will likely create another round of challenges for engine manufacturers [and those] that best handle the integration of these new standards will have a distinct competitive advantage.”