You can't help but notice the positive vibe coming out of Melrose, Ill. about the MaxxForce 15 engine.
The buzz was very much in evidence in Tooele, Utah, earlier this summer, where Navistar had invited more than 1,000 of its dealers and customers to see the new 15-liter up close and in operation for the first time.

Even with all the nay-saying going on in the battle between the competing technologies used to meet EPA 2010 emissions regulations, worried faces were visibly absent among the dealer folk assembled there for the Heavy Duty Boot Camp event. Dealers have a huge stake in this saga. If the engine doesn't work, they have no trucks to sell. There have been problems with Navistar's 13-liter engine, but there have been problems with competitive engines that use the selective catalytic reduction strategy Navistar eschews.

I got a chance to drive an MaxxForce 15 at the Tooele event, and even took one on a longer test drive around Salt Lake City, which appears in the August issue of Heavy Duty Trucking. I also got to spend a little time with Titus Iwaszkeiwicz, Navistar's manager of powertrain product development. He's had a big hand in the development of the 15-liter engine. So I asked him to show me around the engine and point out a few of its unique features and advanced technology.

The video below is a tour on the air management system, from intake to EGR cooler. The most notable change from the MaxxForce 13 is the large EGR mixing valve.

This piece of equipment is unique to Navistar, but its roots go back to Holley carburetors -- the same carburetors that have powered stock cars, street racers and just about every Spring Cup team and NHRA Pro-Stock champion for decades. The Navistar EGR valve was birthed as a high-precision throttle valve for a Holley carburetor.

"We had originally sourced Holley as the supplier of these valves -- though we were not using it quite in its intended application -- and at the time Holley was considering phasing out production of the technology," Iwaszkeiwicz says.

So, like Victor Kiam used to say about Remington razors, "I liked it so much I bought the company."

"Navistar purchased the design and the technology from Holley, and now manufactures the EGR valves internally," Iwaszkeiwicz added.

In the video below, Iwaszkeiwicz explains how the valve works and why he thinks it's the design going forward for EGR valves.

I'm not an engineer, and the few hours I spend behind the wheel of a MaxxForce 15-equipped ProStar + in Salt Lake City that day hardly qualify me to pronounce the technology a success, but it seems to work.

In four hours of driving, the active regen light never came on, save for a few moments after pulling out of the Boot Camp site, where the truck had ambled 50 or 100 times around a 2.5 mile course at 30 mph -- prime territory for setting up a regen event.

You can read more about my test drive of the MaxxForce 15 here. In the meantime, here's what's new from Navistar on the EGR front.