Quality and reliability are the most important aspect of overall customer satisfaction, and Hino and Cummins scored first and second, respectively, in J.D. Power and Associates' 2011 U.S. Medium-Duty Truck Engine and Transmission Customer Satisfaction Study released this week.

Hino Trucks' engines rank highest in customer satisfaction for a fourth consecutive year with a score of 794 on a 1,000-point scale, and perform particularly well in engine reliability and dependability and accessibility to components for service/maintenance, the survey found. Cummins' score was 763.

The 2011 U.S. Medium-Duty Truck Engine and Transmission Customer Satisfaction Study is based on responses from 1,037 primary maintainers of one-year-old conventional cab medium-duty trucks. The study was fielded between June and August 2011.

Now in its fourth year, the study captures customer perceptions of 2010 model-year Class 5, 6 and 7 gasoline and diesel engines, and with related dealer service. Engine reliability and dependability bring the most customer satisfaction, and comprise one of eight categories measured.

Others measured are 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.

The incidence of engine-related problems for medium-duty trucks remains stable from 2010, averaging 39 problems per 100 vehicles (PP100) in 2011, J.D. Power said. However, these problems increased in number over time. During the past five years, the average number of problems with medium-duty truck engines has increased by 13 PP100[1] 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," said Brent Gruber, senior manager of the commercial vehicle practice at J.D. Power and Associates.

"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," he said.

The most recent emissions standards limits went into effect in January 2010. The impact of these changes on medium-duty truck engine quality and customer satisfaction will be reflected in the 2012 study.

"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," said Gruber. "The manufacturers that best handle the integration of these new standards will have a distinct competitive advantage."