I recently had the opportunity to farm test a Ford F-250 4 x 4 Super Duty truck. It was quite an experience. Ford Literally pulled out all the stops when it designed its new scorpion diesel motor and computer-controlled transmission. The new motor was the most expensive engine-building project that Ford has ever undertaken. It has no parts commonality with the Navistar engine it replaces and is loaded with unconventional thinking and design.

Engine

The 6.7-liter engine is rated at 400 hp at 2,800 rpm with a whopping 800 ft.-lbs. of torque at 1,600 rpm. The motor maintains virtually the same amount of torque up to 2,600 rpm before it begins to drop off, making it an incredible pulling powerhouse. The truck I drove was equipped with 20-in. tires and a 3.55 axle ratio. At 60 mph the truck was running at 1,400 rpm and at 70 mph it was running at 1,600 rpm. These low rpm help the truck achieve surprising fuel economy.

The V-8 block is made of compacted graphite iron for strength and weight savings. The intake manifold is below the valve head, and the exhaust manifold is above the valve head. Exhaust gases are directed to the front of the motor where they are blown into the shroud of the turbocharger that sits directly on top of the engine. The arrangement dramatically reduces the distance between the exhaust and the turbo, thus reducing turbo lag. The Honeywell-designed turbo has twin compressors, making it act like a twin turbo setup. The Bosch common rail fuel system operates up to 30,000 psi to send fuel to the engine’s eight Piezo injectors. Each injector has eight holes and can deliver up to five injections per combustion cycle. When the truck is cruising, only three or four injections are used. High-speed glow plugs provide instant starting in below-zero temperatures.

For extra emissions control, the engine uses exhaust gas recirculation, a catalytic converter, a selective catalytic reduction system — where a mist of urea fluid is constantly injected into the exhaust system to break down pollutants — and a soot-collecting chamber. Warnings in the owner’s manual advise that tampering with the exhaust system may adversely affect the warranty.

The computer-controlled, six-speed automatic transmission is all new this year and is Ford built. First gear has a very low ratio for starting heavy loads. When the transmission selector is put in tow position, it automatically puts the truck in engine-braking mode. Electronic sensors in the computerized transmission put it in the right gear for the best performance and efficiency.

Electronic controls

The truck is loaded with electronic controls. If the temperature is below -15°F and the engine block heater is not used, the engine will not accelerate for 30 sec., allowing the oil to circulate thoroughly to prevent engine damage.

A 4.2-in. information screen gives a myriad of readings, including when the soot chamber is regenerating, fuel economy records, and the angle of the slope you are on, both vertically and horizontally.

Several features are especially helpful when towing loads. You have the ability to program specific wagon or trailer numbers and the computer will remember the type of hitch, the diameter of the hitch ball, etc.

Likes and dislikes

This nearly 8,000-lb. truck had plenty of heft to pull two hopper wagons full of corn to market (640 bu.). The engine was so quiet that the people at the elevator didn’t believe it was a diesel. The King Ranch option includes captain’s chairs and Chapparal leather — sweet!

The rapid acceleration of this truck would be a handy feature for those who farm along busy highways. It moves out more like a 3,000-lb. Corvette than a hulking truck.

The engine burns clean. There is never any smoke or diesel smell. Nor is there any of the vibration usually associated with the diesel engine.

The engine compartment is completely full and, because of the complexity of the engine and its electronics, the owner will almost certainly be limited to factory-trained technicians when repairs become necessary.
Prices are $36,830 for the base 4 x 2 regular cab Super Duty with the diesel engine and $39,805 for the base 4 x 4. For more information, visit www.mediaFord.com.