Mercedes Benz ranks highest among heavy-duty engine manufacturers in satisfying customers with vocational trucks,according to the J.D. Power and Associates 2008 Heavy-Duty Truck Engine and Transmission Study recently released.

Now in its 12th year, the study measures customer satisfaction with engines in two-year-old heavy-duty (Class 8) trucks by examining four engine factors. In order of importance, they are: engine quality (30%); engine performance (26%); engine cost of ownership (22%); and engine warranty (22%).

Mercedes Benz, which supplies engines for Daimler Trucks of North America, ranks highest in customer satisfaction among vocational trucks with heavy-duty engines, receiving an index score of 760 on a 1,000-point scale. The manufacturer performs particularly well in the performance, cost of ownership and warranty factors. Cummins (733) and Mack (727) engines, respectively, follow Mercedes Benz in the rankings.

The study finds that sales personnel for heavy-duty truck dealers need to have a better understanding of their customers' engine needs. Forty percent of heavy-duty truck owners either relied solely on the salesperson to choose their engine for them, or purchased their truck "as is" off of the lot.

The average overall satisfaction score is 712 points at two years of ownership when owners let the dealer choose their engine, or purchased their vehicle "as is," which is significantly lower than when owners choose their engines without the salesperson's help (745). 

Additionally, only 29 percent of owners who purchased their truck "as is" or relied on the dealer to choose their engine report they "definitely would" repurchase the same engine brand. Conversely, 45 percent of owners who were actively involved in the engine decision process say they would repurchase the same engine brand.

The study also finds that 43 percent of owners who report they "definitely/probably" will not repurchase the same engine also indicate that they will not repurchase the same truck brand.  

The 2008 Heavy-Duty Truck Engine/Transmission Study is based on the responses of 2,692 primary maintainers of two-year-old heavy-duty trucks (Class 8). The study was fielded February through May 2008.  The vocational segment includes trucks that are used in rugged job applications, such as dump trucks, concrete mixers, and garbage/refuse/recycling trucks.