Mercedes-Benz presented its new Atego in spring. But its predecessor is no slouch, either. The editors from lastauto omnibus compared the hybrid drive to an automatic transmission with start-stop automatic and to a manual transmission. Which Mercedes Atego is most advantageous for distribution transport companies?
The Mercedes-Benz Atego offers copious different models in the distribution segment: three cabs, many combinations of wheelbase and axle drive ratios, as well as numerous engines.
Does the Hybrid Beat Its Competitors?
The Mercedes program offers a hybrid version of the 12-ton truck. 44 kW of additional power provided by the electric drive is to significantly reduce fuel consumption for the Atego 1222 Bluetec Hybrid. How economical the “Atego with two hearts” really is, was the subject of a comparison with its “Blues Brother” with manual transmission and with a silver Atego with automatic transmission.
In addition, three test drivers mimicked three different driving styles. Driver A aimed to drive economically, whereas Driver B focused on performance but without wasteful acceleration. Meanwhile, Driver C, in a pragmatic style blending these two extremes, concentrated on his work and not much else.
250-Mile Test (400 km)
The test route, with an overall length of approx. 250 miles (400 km), comprised everything an average distribution truck is exposed to: a city route with lots of stop and go and many delivery points, a stretch of countryside driving to supply the rural region, as well as a fair amount of freeway-driving.
The Hybrid Scores in City Traffic
The first discipline in this triathlon was urban delivery traffic, in which, quite naturally, the hybrid attracts attention. The gentle but powerful start of the 44-kW synchronous motor remains a source of fascination. The hybrid starts moving as if it were pulled by a powerful rubber band. With respect to noise emission, however, there are few benefits. Even when the truck is standing still, pedestrians still hear the knocking of the four-cylinder diesel engine, which keeps running to power steering and air compressor.
The electric drive requires sensitive driving.
The 12-Ton Truck Accelerates to 12 mph (20 km/h) without Emissions
The 12-ton truck can accelerate to almost 12 mph (20 km/h) before the diesel engine underneath the cab takes over. In order to take full advantage of the electric drive, however, gentle throttle use is required. Otherwise, the 218-HP diesel engine will immediately kick in to take over propulsion. The interaction of electric drive and diesel engine, by the way, is markedly harmonious; there are no jerks during the switch from watts to horsepower.
The silver Atego with a six-speed automatic transmission is also very competitive in the inner city jungle. The driver can focus on navigating past pedestrians and cars. It is only at a traffic light that the Atego may confuse the driver after stopping by taking a fairly long time until the start-stop system finally turns off the engine. Starting after the traffic light turns green might also feel a bit sluggish to impatient drivers. It is tempting to turn off the system.
The blue Atego with manual transmission made its way through the city in a tried and true way. The transmission is smooth and the shifting is exact. Still, having to step on the clutch continually to change gears seems like an anachronism in 2013.
The Hybrid Wins on Fuel Consumption
The victory of the hybrid regarding consumption was expected. After a total of nine city trips, the green Mercedes was nearly 24 percent more economical than the Atego with manual transmission and still 20 percent more economical than the Atego with automatic transmission and start-stop system. The average speed was not considered, although all three vehicles made the same number of stops. As expected in city driving, the different driving styles did not lead to significant differences in fuel consumption. City trips with its extremely variable traffic volume and flow are too limiting on individual driving styles to make measurable differences. The table therefore only provides one mean consumption value for all three drivers.
The subsequent two-hour trip on state and county roads highways promised more-concrete results. With a load of almost 12 tons, all three Ategos would go on this second leg with gentle rocking, as if buoyed by gentle surf. Firmness is not the strength of the Atego; its ride may even be called overdamped.
This is complemented by the dutiful, but not overambitious, unit injector system. The engine fits the image of a mature worker using his resources smartly and economically. Drivers liked this balanced character that affects the driving style. Despite different driving styles, the average speeds were almost equal, although the Atego can translate the electric boost into fuel-consumption advantages, which may be surprising to hybrid novices. With an average fuel consumption of almost 3 liters/100 km below the truck with the automatic transmission and still 2 liters/100 km below the manual-transmission truck, the hybrid was the master of diesel economy. Lower consumption by 14 percent is nothing to sneeze at, especially at equal road performances.
Minor Differences on the Freeway
The differences were smaller for the freeway test. Irrespective of the driver-related lower average speed, the consumption for the three Atego trucks was very close, with a difference of approx. half a liter/100 km. The hybrid can only use its advantage when entering the freeway. Even the extremely hilly highway from Mainburg to Holledau offered few opportunities for recovery and cruising.
The overall average consumption of the hybrid over all stages was more than two liters/100 km lower than that of its established siblings. Surprisingly, the silver Atego with a Telligent automatic transmission came in behind its blue sibling with manual transmission, which noticeably benefits from its permanent-magnet retarder in the power train during downhill driving.
As expected, the automatic transmission with its seemingly higher consumption compensated for the different driving styles and efficiently converted them into very close results. This shows that automation is good, in particular for different drivers with different driving styles.
60 Percent Surcharge for the Hybrid
It is not the additional 770 lbs. (350 kg) of the hybrid system and certainly not the almost perfect operation that cause the economic downfall of the diesel-electric Atego. The considerable surcharge of almost 60 percent on the purchasing price of a normal Atego 1222 turns the small Mercedes with the two “hearts” into a loser. That’s why the hybrid, with approx. 1000 vehicles sold to date, is mainly a beacon showing the way to a presumed hybrid future. According to truck manufacturers, however, this future lies not with the previously favored city users, but rather in long-distance hauling, where the high mileage will ultimately justify the additional costs.