When I first heard about Navistar International’s HD2 program-the code name for the line introduced as the 9000i earlier this year-I had to wonder: when everyone else has a new-from-the-ground-up truck (look around, they all do), why would Navistar tinker with the old International aluminum cab?

That tinkering paid off in some compelling reasons to look long and hard at the Eagle 9900ix, the premium over-the-road truck in the 9000i line. I discovered as much at the Mid-America Trucking Show in Louisville, Ky., earlier this year when I took a brief, one-day run out of Louisville and across Indiana on I-64.

The 9900ix (the “i” stands for innovation, the “x” for extended hood) is Navistar’s first 130-inch BBC. The big hood requires some compromise standing way out in front and tall, especially when a five-inch-tall bug deflector accentuates the front edge. But the view through the one-piece glass is superb and visibility to the sides is excellent since the windshield pillars are set reasonably far back. Designers raked back the windshield at an almost industry-standard 22 degrees, rounding the glass at the A pillar to turn the air and keep it attached to the cab’s side surfaces as it moves down along the truck. A redesigned bulkhead and the dashboard adds a couple of inches in knee and belly room. And new styling on the hood includes a low waistline, adding enormously to visibility down and to the front and sides of the truck without compromising the width of the cab.

The overall feeling of spaciousness and the enhanced visibility is complemented by the swiveling seats, wide cab, and the high-rise ProSleeper. Most cabinets are molded, with overhead bins in the cab and modular lockers and shelves in the sleeper. Our test unit was equipped with an upper bunk, which has a very robust latch system, and there’s a new storage cabinet below the TV shelf with molded steps to help access the upper bunk.

Under that long hood, this truck’s Caterpillar 550 3406E easily cools behind the big, square-shouldered 1150 square-inch radiator. External air filters make for a clear bulkhead and there’s no engine intrusion at the back of the block. In fact, Navistar could easily eliminate the small doghouse intrusion into the cab: the engine stands completely clear of the firewall.

Heading onto the I-264 southern loop around Louisville, I noticed the good turning radius despite the 9900ix’s wheelbase and long hood. Part of the credit comes from last year’s update to the front of the frame, when the front crossmember was redesigned with a revised spring and bumper mounting. And there was a revised drag link and pitman arm, allowing a 40-degree wheel cut, despite the 30-inch axle forward position.

The general comfort areas of ride and noise seemed well-contained. The longer wheelbase of this unit-260 inches compared to the 244-inch 9900 tested a year ago-didn’t add any frame bounce to the ride, and steering and handling appeared not to offer any surprises. Since this was an abbreviated drive in a prototype 9900ix, we didn’t put the sound level meter on the unit. Many things often change between prototypes and early production, including fits and finishes.

I might have expected a quieter environment, though, if only because International cabs now have extensive insulation in the door. This has been added to improve performance of the heating/ac, blocking off a heat path through the door skins that is very familiar to most truckers. That, and the major revision to the heater/ac-which still mounts under the passenger seat-bode well for excellent climate control in the worst conditions. Navistar says the new trucks offer best-in-their class heating and temperature pull-down when heating or cooling a truck that’s been sitting idle. Oh, there’s another thing about that long nose. The proportions of the hood, cab, and the additional chrome around the grille and headlights all work well together. The Eagle 9900ix is one very good-looking truck.

ROAD NOTES: 9900ix

o The 9900ix’s interior measures up well. Some examples: width (window to window): 89 inches; height (floor to ceiling): 75 inches; width between seats (armrests down): 18 inches; driver seat to firewall: 20 to 28 inches, accounting for seat travel; driver footwell width: 24 inches; maximum sleeper ceiling height: 102 inches; sleeper depth: 69 inches; sleeper width: 94 inches; driver’s view to the road: 26 feet, 9 inches.

o Since this was a prototype and the ride was brief (88 miles), I didn’t track fuel mileage. However, Navistar says the new Internationals are between 2% and 5% better aerodynamically than the trucks they replace. This has to add up to fuel savings over the long haul ranging from 1% to 3%-not a huge gain, but a step in the right direction. And with the ’99 engines maintaining fuel economy despite more stringent emissions settings, there are fuel gains to be had there.