The 14th annual U.S. Heavy-Duty Truck Engine and Transmission Study from J.D. Power and Associates indicated that engine and transmission satisfaction among “primary maintainers” is up from the 2010 study.
According to J.D. Power, 42% of owners of heavy-duty truck engines report experiencing an engine-related problem. That figure is down from 46% in the 2010 study.
EPA 2010 engines will be reviewed in the 2012 survey, the organization said.
The annual study, which was conducted between February and May of this year, measures Class 8 engine and transmission satisfaction on one model-year old models. Satisfaction is measured based on eight factors: engine reliability and dependability; engine warranty; acceleration when fully loaded; electronic control module; accessibility to components for service or maintenance; vibration at idle; maintaining speeds on grades; and average fuel economy.
This year’s study, which surveyed 1,651 primary maintainers, found 66 problems per 100 vehicles (PP100), down from 72 PP100 in 2010. As a result, engine satisfaction increased 22 points to an average of 739 on a 1,000-point scale.
“It’s encouraging to see that the number and frequency of problems is improving,” said Brent Gruber, senior manager of the commercial vehicle practice at J.D. Power and Associates. “With the new technology required to meet emissions standards, today’s engines simply are more problematic than the previous generation. So, while it’s possible that manufacturers can continue to improve the quality of the engines, it’s unlikely that they’ll quickly get back to the pre-2004 levels.”
The study revealed that users of Navistar’s International MaxxForce engines were the most satisfied, recording an average of 760, performing well in engine reliability and dependability, engine warranty, vibration at idle, and average fuel economy.
Cummins (736), Detroit Diesel (733) and Mack (733) rounded out the top four spots. J.D. Power said the sample sizes on Caterpillar, Mercedes-Benz, Paccar, and Volvo engines were too small to be included in the study.
The most-commonly reported engine problems are issues with the exhaust gas recirculation (EGR) valves (cited by 23% of owners) and electronic control module calibrations (21%).
“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.”
The study also indicated that as average mpg improves, so did satisfaction. Of owners who reported an average fuel consumption of 5.0 to 5.9 mpg, engine satisfaction averaged 5.9 on a 10-point scale with 58% of those owners indicating they “definitely will” or “probably will” spec the same engine in their next truck purchase.
But, those averages increase to 7.1% and 66% engine loyalty for those who average 6 mpg or more, J.D. Power said.
Transmission satisfaction also increased, averaging 820, up two points from 2010’s survey. Owners who experienced at least one transmission-related problem had a satisfaction level of 706 versus 829 for those without a problem.
Owners of fully automatic transmissions had an average satisfaction of 824 vs. 819 for those with manual models.