Extreme Truck Sports Diesel Power

International Harvester built the Scout sport utility vehicle from 1961 until October 1980, when it became victim of the near financial collapse of IH. Now, after a lengthy hiatus and a few corporate makeovers, International Truck and Engine Corporation is back in the SUT market with one serious brute called the 7300 CXT (Commercial Extreme Truck), said to be the largest pickup in the world.

CXT is designed for those who work and play big.

One popular design theme found in pickups and SUVs in recent years is to give them styling cues from the big rig trucks. International goes just a step farther, why not simply give the consumer the big rig itself recast as a pickup? And that’s essentially what they’ve done. At 258 inches in overall length, the CXT is 31 in. longer than the Ford Excursion, some 50 in. longer than Hummer 2.

In fact, with a GVWR of 25,999 lb. the CXT just remains in the Class 6 truck category. That means it is not necessary to secure a commercial driver’s license to operate one. Class 7 includes trucks with a GVWR over 26,000 lb., and those do require the pro license.

International’s primary target for the CXT is commercial business operators from lawn care to masons to carpenters and every trade in between. It is claimed to be the world’s largest production pickup and it does have a 12,000 lb. payload, three times that of a normal pickup. It has optional dumping and tilt bed capability so it is a serious commercial-grade truck.

But International fully expects to find interest from the consumer market as well. It may only amount to dozens or hundreds of customers per year, but for people who like to make a statement with their wheels, here’s one that quite simply can’t be ignored.

The interior is functional, yet surprisingly stylish for a larger-than-life SUV.

It has first-rate appointments and all the amenities consumers have come to expect from drop-down DVD to XM satellite radio and lots of custom options. The 4-door crew cab version has plenty of room for six adults. It sits up high providing a commanding view of the road. Air conditioning is standard. Base price is $93,000. If that or filling up a 70 gallon fuel tank at today’s prices don’t slow you down, think about what you get.

Standard power for the CXT is International’s ever-evolving DT466 mid-range diesel, which delivers 220 hp and 540 lb.ft. of torque in this application. Higher horsepower engines are also available. The DT 466 itself has ratings as high as 300 hp and 860 lb.ft. of torque.

This year, International redesigned its I-6 family of inline 6-cylinder engines, consisting of the 466, the 530 and the 570 (designations indicate the displacement in cubic inches). These are all four-cycle diesels. The 466 has a bore and stroke of 5.49 in. by 4.86 in. and a compression ratio of 16.1:1.

The new design went into production in February of this year. It is a very robust design. Features retained from the previous design include replaceable induction hardened wet cylinder sleeves, valve seat inserts and valve guides, positive valve rotators and roller cam followers. Engine life to first overhaul is 500,000 miles. The new design employs an innovative air management system incorporating an Electronic Variable-Response Turbocharger (EVRT) and cooled Exhaust Gas Recirculation (EGR).

Produced for the 466 by Borg Warner, the turbo has adjustable vanes to optimize boost over the entire engine operating range. Its variable vanes pivot and effectively change the geometry of the turbo, adjusting to instantaneous engine speed and load and thus minimizing “turbo lag.”

EVRT allows the engine to hold peak torque significantly longer than the previous design and that means left shifting for the transmission. It is electronically integrated with the engine and fuel system for high performance and efficiency.

Cooled EGR is new to the 466 and it reduces NOx emissions and provides for more efficient combustion. A portion of the exhaust gas is diverted through a gas-to-coolant heat exchanger then remixed with air entering the engine for combustion. This reduces peak cylinder pressure temperatures in the cylinder where oxides of nitrogen are produced.

DT466 diesel engine makes 220 hp and 540 lb.ft. of stump-pulling torque.

The DT 466 also employs International’s G2 (Generation 2) electro-hydraulic common rail fuel system. This latest fuel system has a new digital spool valve for very precise fuel metering that is smaller, lighter and more responsive to driver input than the earlier design.

This is a unique common rail system as it utilizes engine lube oil as a pumping medium for a dedicated hydraulic pump. This pump, produced by Bosch Rexroth, maintains 3,000 psi oil pressure in a common rail. Then the G2 injectors, produced by Siemens VDO, intensify that pressure by a ratio of 7:1 and inject the fuel into the combustion chambers at 21,000 psi.

So this approach does away with external high pressure lines yet still delivers the very high injection pressures required by today’s cleaner burning, more efficient diesels.

G2 injectors have dual timing control with a sensor looking at crankshaft position and a confirming sensor for the camshaft position. And these injectors are much smaller than the previous ones. They need to be to accommodate the new four-valve design of the engine.
 
The four-valve design yields a more complete mix of air and fuel and provides the engine capability to run with higher power, more complete combustion, and lower emissions. This design has now been adapted to all International I-6 diesels.

The new injectors can handle fuel with up to 20 percent bio-diesel and also low-lubricity jet fuel (Jet A and JP 8).

The 466 delivers power to the CXT via an Allision 2500 5-speed automatic transmission. Standard drive is referred to as 4X4 On- Command All-Wheel Drive. The truck has a 2- speed Hi-Lo transfer case.

The Siemens VDO G2 injectors can handle fuel with up to 20 percent bio-diesel and also low-lubricity jet fuel (Jet A and JP 8).

The front driving axle is rated at 10,000 lb. and the rear driving axle is rated at 17,000. The CXT is equipped with air suspension, air ride seats and 4-channel ABS air brakes.

The truck is being produced at International’s manufacturing plant in Garland, Texas. Even for that state, this is one big pickup and it’s diesel power all the way.