"After a year of working with the new emission engines, progressive fleets are proving the engines and they're satisfied they'll do the job for them," said Christensen. "We're confident in both EGR and ACERT technology and we've been working with the engine companies and have the right cooling and installation packages in our trucks."

While new engines have been the top story for the past year, it hasn't been the only story, according to Christensen. He said the recent downturn in the trucking industry has re-focused fleets and owner operators on curbing operating expenses and wisely choosing their power units.

Christensen added that life cycle costs have come to the forefront for most truck operators.

"Many were rudely awakened during the used truck crisis a few short years ago," he said. "Many were upside down in the value of their trucks and therefore had to keep an aging fleet. Those who took resale value into the buying criteria faired well."