Star Power

Jack Roberts | February 01, 2012

Test Drives

2012 International ProStar+ with MaxxForce 15-liter shines during editor’s test

The light and space of the Texas prairie around Dallas can zap a trucker’s brain — especially on a crisp fall morning at the end of a months-long drought. The landscape is a dull, bleached-out tan every way you look.

If I throw a glance over to my right-hand rear-view mirror, I can see the Dallas skyline hovering in the distance behind me. I’m heading south now, on Interstate 45, straight into the famous Texas hill country to put my new rig through its paces and find out if the Big Bore 15-liter pounding away in front of me will deliver the goods. So far, this new MaxxForce 15 diesel is performing as advertised as it powers my 77,000-pound gross with relative ease.


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4. Thread the horn wire through the VIP 39’s center and then slip the wheel onto the splined shaft, making sure the steering wheel spokes are level. Reattach the locking nut and tighten until snug.


Truckers News Executive Editor Jack Roberts puts the ProStar+ and 15-liter MaxxForce engine through their paces.


A lot of people in those cars are checking out my tractor when they roll past. It is one sharp-looking truck with a gleaming orange-and-charcoal paint scheme.

To most of the four-wheelers, the ProStar+ is simply what passes for a conventional style tractor these days. Truckers with a more practiced eye will note immediately that this is an extremely “slippery” design. True, it pays definite homage to the great International conventionals from years gone by. But the sharp edges and flat surfaces that defined many of those older designs have been replaced by smooth, curved fenders, grille and hood. In fact, all the edges across the front and sides of the tractor have been aerodynamically optimized, giving the ProStar+ a distinct aerodynamic boost.

Aaron Tennant is president and CEO of Tennant Truck Lines out of Orion, Ill. His company runs ProStar+ tractors as their standard spec vehicle and he says his drivers’ experiences closely mirror my own impressions. “Our drivers like the ride and how quiet the truck is. They also give it very high marks for the interior styling, comfort and room,” he says. “It’s a very quiet truck. And as the company owner, I like them for their fuel economy. We’ve tested them against other trucks and found that the ProStar+ delivers about three-tenths of a mile per gallon better fuel economy than other models.”



The Prostar + boasts plenty of storage space both in the front of the cab (shown here) and the sleeper compartment.



During the pretrip, a quick unfastening of the fender latches and a gentle tug on the handgrip integrated into the top of the chrome grille is all that is needed to open the hood and check out the 15-liter MaxxForce. This is the engine naysayers said International couldn’t pull off: a 15-liter beast forged in the company’s Huntsville, Ala., engine plant, combining the lower components, such as the block and camshaft, from Caterpillar’s C-Series family of diesel engines with International’s high-pressure fuel injection system and sophisticated electronic engine control systems. This is an exhaust gas recirculation-only engine — meaning there is no diesel exhaust fluid tank or exhaust aftertreatment system. International uses “heavy EGR” to burn off NOx particulate matter during the combustion process by recirculating exhaust gases back into the combustion chamber. Access to all the major engine systems — antifreeze, power steering fluid, engine oil and so on — is a snap.

At a glance, there’s not much going on visually to tell you there’s a MaxxForce 15 under the hood of this ProStar+. True, there’s a chrome badge on both sides of the engine cowl, but it’s understated. But if you look right in front of the A Pillar, you’ll see a 3-inch-long body insert with a faux air vent inserted between the engine compartment and cab. This filler is necessary because the 15 is 3 inches longer than the MaxxForce 13 engine: This is your strongest visual clue that the ProStar+ passing you on the left has a big bore engine under its hood.

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