More truck drivers are complaining about engine problems and there is a decrease in overall satisfaction with powertrain, according to a recently released report from J.D. Power and Associates.

The 2012 U.S. Heavy-Duty Truck Engine and Transmission Study is in its 16th year and studies the level of satisfaction that truck drivers have with their engines and transmissions that are at least one model-year old.

Drivers' satisfaction is measured by eight key factors, which include engine reliability and dependability, engine warranty and acceleration when fully loaded.

"At the industry level, the new, more complex engines designed to meet EPA regulations are resulting in additional problems and downtime, which also has a financial impact on owners because they're not making money when their truck is down for service," said Brent Gruber, director of the commercial vehicle practice at J.D. Power and Associates.

Trucks were fitted with technology that was designed to reduce emissions and make them compliant with the 2010 EPA regulations, but now the technology is causing problems in the engines of the trucks.

"The new engines are proving to be more fuel efficient and allowing greater up-time between service, so despite initial quality issues, the new technology may offer a greater return on investment in the long run," Gruber said.

According to the study, 46 percent of owners of heavy duty trucks that are one model-year old reported they had some type of engine-related problem, which is a 4 percent increase from the 42 percent who reported problems in 2011. Out of the problems that were reported, 23 percent reported an issue with the electronic control module calibration, 20 percent had a problem with the exhaust gas recirculation valve and 16 percent reported issues with the electronic engine sensors.

Gruber said that once manufactures fix quality issues that are related to the new technology that has been installed in heavy duty trucks, customers expect to see some added benefits with the new engines, such as an increase in the average reported engine service interval, which increased from 20,303 miles in 2011 to 22,703 miles in 2012.

Detroit ranked best
Detroit ranks the highest in customer satisfaction, reporting a score of 753, which is a 20-point improvement from 2011. Cummins ranks second at 729 and Caterpillar ranks third at 721.

Overall satisfaction with the transmission in heavy duty trucks averaged 812, which was down eight points from 2011. The decrease in satisfaction is thought to be a result of a lower amount of reliable and dependable transmissions and drivetrains.

While heavy duty trucks have had problems reported with their engine and transmissions, the number of new car sales is continuing to show positive signs. According to Kelley Blue Book, August new car sales will improve on its performance last year by 18.7 percent.

"Although economic jitters remain top-of-mind for many, those consumers seeking replacement vehicles continue to opt for new cars with used-car values remaining high," said Alec Gutierrez, senior market analyst of automotive insights, Kelley Blue Book.  "In fact, a recent survey of KBB.com shoppers conducted by Kelley Blue Book Market Intelligence found that 53 percent of respondents indicated they were considering a new vehicle rather than used due to elevated used-car values.  Savvy consumers are likely opting to pay an extra $20 or $30 per month to buy or lease a new car than settle for a used vehicle with 20,000 miles or more."