Types of Truck Engines & Their Differencesby Richard Rowe
There are over a dozen different kinds of diesel engines used in over-the-road trucks today, and each has a following of its own. The engine type preferred by an individual driver has at least as much to do brand loyalty as performance, fuel economy, cost, maintenance or any other aspect of its design.
Detroit Series 60
Detroit Diesel was formed in 1937 by GM, so the company has plenty of experience in designing and building engines. The series 60 engine is an overhead camshaft Inline-6 engine, and is one of the most common on the road. The D60 is a fairly reliable engine known for its throttle response, clean emissions, flexible torque and high-RPM horsepower. Fuel economy is not the greatest on the road, but the engine's other virtues make it a popular choice for large fleets and owner-operators alike.
Few other manufacturers have the provenance of Caterpillar. CAT got its start late in the 19th century producing steam-powered tractors, and branched out from there to industrial applications like bulldozers and construction equipment. CAT's popular N-Series motors are expensive, heavy and lack the high-RPM power of some others, but carry on the company's industrial legacy by providing massive low-RPM torque and tank-like reliability. These engines are preferred for those driving in mountainous regions, where steep grades and heavy loads necessitate an engine with this kind of grunt. For heavy hauling in extreme conditions, many owners agree that there simply are no substitutes for a CAT.
If ever there were such a thing as a "corporate engine," then the Cummins is it. Cheap to buy and very long-lived when properly maintained, the Cummins offers good fuel economy at the expense of some power. It's not as though the Cummins lacks horsepower, but its inherent design means that high-horsepower levels only come by sacrificing some of its fuel economy. This makes the Cummins ideal for smaller companyies that can't afford more expensive new Detroit or CAT engines. Beware of buying used, though; the Cummins is strongly dependent on routine maintenance, so any cost benefits it may have will disappear soon after the warranty expires.
Among Volvo's subsidiaries are Mack, Renault and Nissan Diesel. The Volvo family of engines might best be thought of as the "anti-CAT," as they were originally developed for use in Europe, where speed is electronically limited to 56 mph. As such, the Volvo family of engines sacrifice all power and torque in the name of fuel economy. While emissions, reliability and fuel economy are excellent, this engine is best suited for light-duty applications (like buses and cargo trucks) in fairly flat areas where torque is not required.
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