For fans of big, extremely capable trucks, the Unimog is the ultimate forbidden fruit. Look at it -- the truck is massive and designed for hard work and unstoppable off-roading. And at Auto Shanghai 2013, Mercedes-Benz announced that the company has made the trucks Euro VI-compliant. This introduction followed the introductions of Euro VI-compliant Actros, Antos, Arocs, and Atego trucks, which use the same engines.
Mercedes-Benz introduced a 10-model Unimog line -- plus two- and three-axle versions of the low-entry Econic truck -- all with engines that adhere to Euro VI emissions standards, which will go into effect starting January 1, 2014. The Unimogs are available in a range from the U 216 to the U 5024, and the use of the new engines means that not only are the engines cleaner, but they are more powerful and more efficient as well.
The new Unimog model range has changed. The compact entry-level (for this size category, anyway) that was once named U 20 is now called the U 216 and U 218. Next in the line are models with more powerful engines, now known as the U 318, U 423, U 430, U 527, and U 530. With the new names, the first number refers to the vehicle's size (if the number starts with 4, that refers to the current U 400), and the next two numbers stand for the first two numbers of the amount of horsepower the engine puts out. So the U 423 puts out 230 horsepower.
Along with the name changes, the Unimog receives new features like a redesigned panoramic cab, new power hydraulics and work systems, and synergetic traction drive. This last feature allowed a changeover from a manual transmission to a hydrostatic unit, making the Unimog more efficient. The off-road-biased Unimog U 4000 und U 5000 designs were also updated, and are now known as U 4023 and U 5023.
The Econic trucks offer two- and three-axle chassis versions, and are available with 4x2, 6x4, 6x2, and 6x4 drive options. The trucks also have electronically steered forward and trailing axles. Mercedes improved ergonomics in the cab, and also reduced fuel, repair, and maintenance costs, making it more cost effective. And, even with the Euro VI compliance, the truck's payload remains the same.
To make the Unimog Euro VI-compliant, the trucks use two series of BlueEfficiency Power engines, with radically new designs. These engines are also more efficient when using work implements, because greater output is now available. The Econic also uses two engines from these series: engine types OM 934 and OM 936. There are three four-cylinder and two six-cylinder versions and, as is often the case with heavy-duty trucks, size ranges from 5.1 to 7.7 liters, with 156 hp to 354 hp, and up to 479 lb-ft of torque in the entry-level Unimog U 216. The 7.7-liter inline-six OM 936, used in the U 427, U 430, U 527, and U 530, puts out 272-299 hp. Top torque is 885 lb-ft. The fuel-efficient engines provide extremely clean exhaust gas and reduced consumption in the Unimog, and in the Econic, fuel consumption is down four percent. Plus, torque and acceleration have been improved.
The engines use solenoid injectors with 10-hole jets, and are long-stroke engines with cooled EGR. There's also a new system that includes an oxidation catalytic converter, a closed particulate matter filter, the use of AdBlue injection, and an SCR catalytic converter. The result is that the new engines have up to 90 percent fewer exhaust gas and particulates than the previous engines. As of now, Mercedes-Benz Trucks and Special Trucks are the only manufacturers in Europe to offer Euro VI-compliant light, medium, and heavy-duty trucks, as well as special-purpose vehicles. Production of the new vehicles will begin at the plant in Woerth, in September.