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To complicate matters further, 2002 was when Knight switched from the N14 to the ISX engine platform. Unfortunately for both companies, the 2002 testing uncovered problems that continued to be issues after the engines had gone into production. "After '02, we did see our share of little glitches that occurred," Williams says. "A lot of them were electrical; a lot were EGR valves that we had issues with."

PERFORMANCE & RELIABILITY

For the 2007 engine test, there was no retrofitting involved. "This truck was engineered with the engine, instead of having a retrofit situation where you had to weld a bunch of parts together," Williams says. "So, we've got a current chassis, we've got a current cooling package, we've got the aftertreatment and the engine all combined in a package that should be the same as the package that comes out in 2007.

"There are two things in particular that Volvo has done to their chassis," he continues. "Number one is they've opened up the airflow. In other words, they've widened the opening where airflow comes in. It's a slightly larger front grille; you'd never even notice the difference. And number two, they've got a wider radiator. My understanding is that that's going to be a common solution among the OEMs."

Since June, 2005, that truck has been making a regular run between Phoenix and Long Beach, CA, filling up with ULSD at a British Petroleum facility in Long Beach. The ISX 400ST 1450/1650 engine, mated to an Eaton 10-speed transmission, has a somewhat higher rating than Knight's current trucks. The new CJ-4 engine oil is being supplied by Cummins.

According to Williams, Knight has been concentrating on questions of performance and reliability with the new engine, and, after over a year, the test results for both are almost consistently positive.

"We've gotten very actively involved in understanding what it is, and what it isn't," Williams says of the test. "We've tried it, we've tested it, and at this point we're not afraid of it."

The '07 engine is essentially a "refined" 2002 ISX, Williams explains. "They've moved the EGR valve to the cool side of the engine, which, they're anticipating, should virtually eliminate failures. Other than that, you've got a few little things here and there, but essentially you're talking about aftertreatment. And with the aftertreatment, there's not a whole lot of moving parts, so we didn't anticipate a lot of problems."