WESTLAKE VILLAGE, Calif. – Overall quality of heavy-duty trucks has improved substantially compared with 2010 models, but whether these gains can be sustained in the face of greater production and new emissions regulations remains in question, according to the J.D. Power and Associates 2011 U.S. Heavy-Duty Truck Customer Satisfaction Study.

The study finds that quality of one-model-year-old Class 8 trucks has improved by 29 problems per 100 vehicles, PP100, in 2011, compared with 2010.

Among trucks in service between 13 and 18 months, problems have decreased by 23 percent during the past six years, declining to an average of 198 problems PP100 trucks in 2011from an average of 257 in 2006.

The trucking industry is experiencing a significant sales recovery. However, the higher demand presents some challenges for both manufacturers and suppliers in maintaining existing quality levels, particularly as the increased build rates are coinciding with the release of new 2010 EPA emission engines, said Brent Gruber, senior manager of the commercial vehicle practice at J.D. Power and Associates.

Historically, customer satisfaction with heavy-duty trucks has declined immediately following the introduction of engines that meet revised EPA regulations such as in 2010 and 2007.

"Engine reliability and dependability has the greatest impact on overall product satisfaction, so truck and engine manufacturers will need to pay particular attention to engine build quality as they increase truck build rates," said Gruber.

Meanwhile, the survey also measured the satisfaction of primary maintainers of one-model-year-old Class 8 heavy duty trucks in three product segments: pickup and delivery, vocational and over-the-road.

International ranks highest in heavy-duty truck customer satisfaction in the P&D segment, improving from second rank position in 2010. Kenworth follows in this category.

Kenworth ranks highest in Class 8 customer satisfaction with dealer service and performs particularly well in the service facility factor.

In the vocational, Peterbilt ranks highest and performs particularly well in the engine and cost of operation factors. International is second.

In each segment, satisfaction is determined by examining six key factors: engine; transmission; ride/handling/braking; cab/body; cost of operation; and warranty.