TORONTO, Ont. — Everyone at the Canadian Fleet Maintenance Seminars this morning was curious to hear first-hand reports on the performance of new 2007 engines.

Unfortunately, virtually nobody in attendance has yet purchased any of the new engines so there was very little information to share.

Performance of the new engines is the industrys best kept secret, according to Technology and Maintenance Council (TMC) co-chairman, Darry Stuart. However, TMC was able to pass on some early feedback from its US members.

To date, the biggest surprise is that diesel particulate filter (DPF) re-generations are occurring far more frequently than expected, said Rob Braswell, technical director of TMC.

Were seeing re-generations every 25,000 miles instead of 50,000 miles, Braswell said.

Other concerns have arisen about the intense heat created during re-generations as much as 1,200 C. The high re-gen temperatures have actually melted the cowlings off some auxiliary power units, Braswell said.
Beyond that, 2007 engines appear to be operating relatively problem-free, according to Stuart. He told maintenance managers not to fear the new technology and pointed out DPFs have been widely used in transit applications for years.

Fuel economy is pretty much the same, according to US fleets running 07 engines, Stuart said.

Steven de Sousa of Mack Trucks provided some Canadian perspective, saying the rollout of 07 engines was delayed by the unavailability of ultra low-sulfur diesel.

The fuel wasnt ready when it was supposed to be, he explained. However, now that the first 07 engines are on the road, de Sousa said its been smooth sailing. He said heat issues during re-generations can be addressed by purchasing a diverter, which mixes cool air with the exhaust, bringing down overall exhaust temperatures.

He added the re-generation frequency is duty cycle-driven and that Mack is experiencing no fuel consumption degradation compared to 02-06 models.

For a full report from CFMS, see the July issues of Truck News and Truck West.