Truck News

Feature

Detroit transmission dazzles in debut

NAPA VALLEY, Calif. – Daimler Trucks North America has taken the wraps off its highly anticipated automated manual transmission, showcasing it to trade press editors during a recent test drive.


NAPA VALLEY, Calif. – Daimler Trucks North America has taken the wraps off its highly anticipated automated manual transmission, showcasing it to trade press editors during a recent test drive.

The Detroit DT12 – a 12-speed, two-pedal automated transmission – has been brought to North America to round out Daimler’s integrated powertrain, complementing its existing Detroit engines and axles.

“The DT12 transmission complements the Detroit engines and axles with features that positively impact efficiency and performance,” said Brad Williamson, manager, engine and component marketing for Daimler Trucks North America. “The Detroit brand has long been synonymous with power and economy, and the DT12 continues our legacy of benefitting our customers’ bottom lines.”

Among its attributes is a lightweight design, thanks to an aluminum housing and single countershaft. Daimler officials said the DT12 weighs about 100 lbs less than the Eaton UltraShift Plus. While the DT12 will provide an appealing alternative to the UltraShift Plus, most inquiring fleet management minds will want to know how it stacks up against Volvo’s slick
I-Shift, which is the benchmark automated transmission against which all others will be measured. Volvo has enjoyed tremendous success since bringing its own integrated automated transmission to North America in 2007, and Daimler now seems poised to steal some of its thunder with the introduction of its own Detroit DT12. Since comparisons to the I-Shift are inevitable, I won’t shy away from them.

Initial observations, after spending close to an hour driving the DT12 in a Freightliner Cascadia Evolution on a variety of road types at various speeds, the DT12 seems to do everything the I-Shift does – and very well. A few examples? The I-Shift offers Eco-Roll, which safely disengages the transmission on downhill grades and allows the truck to coast at idle to save fuel. The DT12 has eCoast, which does precisely the same. The I-Shift has Hill Start Aid, which holds the vehicle’s position on a steep grade, giving the driver ample time to apply the throttle without rolling backwards. The DT12 has, well, Hill Start Aid, which, you guessed it, does likewise.

Another useful feature you’ll find in both products is what Detroit dubs Creep Mode. Say good-bye to the clumsy backing maneuvers that were a common complaint with earlier generation automated transmissions. Creep Mode provides smooth, effortless low-speed driving – in reverse or forward gears – which is handy when positioning trailers, navigating a tight yard or crawling along in bumper-to-bumper traffic. The feature can even be used to rock the truck – potentially freeing it from mud or snow – by quickly switching from forward to reverse gears using only the shift lever.

Unique to Daimler is the placement of the DT12’s shifter, mounted to the side of the steering wheel in the form of a cleverly designed control stalk, which also provides cruise and engine brake controls. Volvo mounts its shifter on the side of the driver’s seat, while Mack, Allison and Eaton prefer a push-button console mounted to the dash. What’s better depends entirely on the operator’s preference, but the location of the DT12 shifter on the side of the steering wheel is intuitive and easy to operate without distraction.

Drivers can override the DT12’s gear selection (when it’s safe to do so) and can alternate between Eco and Power modes. Power mode provides a little extra jump, great for starting from a stop with a heavy load. When the extra torque is no longer required, the transmission automatically reverts back to Eco mode, which provides the most efficient performance.

Another treat for drivers is a Kick Down feature, which provides a burst of acceleration when, as the name applies, the throttle is mashed – or kicked down. This is useful when passing or trying to put some space between yourself and another vehicle.

The DT12, like the best automated manual transmissions, loves to skip shift. It almost seemed to be showing off a little as it disregarded first, third, fifth, seventh and ninth on my way up to 12th gear when pulling away from a red light. Skilled drivers could do this just as well…maybe.

But the reality is, most newer drivers – especially the younger ones – aren’t as proficient at jamming gears as the older guard. And that’s an understatement. The DT12 promises to narrow the gap between the most and least skilled drivers in any fleet, which could significantly improve fleet-wide fuel economy.

“It closes the gap in fuel economy,” Williamson explained. “This will squish that standard bell curve in a typical fleet so that you’ll get better average fuel economy over all trucks in the fleet. The good drivers will stay really good and the others will come up to their levels.”

Drivers will appreciate the variable speed cruise control function, which allows the engine brake to regulate speed without compromising fuel efficiency. When set to low mode, the engine brake will keep the truck’s speed close to the set cruise speed; ie. It may keep the truck from exceeding the set cruise speed by more than 3 mph. At the medium setting, the engine brake will allow the truck to exceed the set cruise speed by a little more, say 6 mph. This provides better fuel economy in rolling hills as it better utilizes the truck’s momentum. The high setting is ideal for flat terrain and works like your typical engine brake, giving the driver more control over speed management.

Daimler folks have only good things to say about their rival’s I-Shift, and I believe they’d be heartened to hear there initially seems to be very little to separate the two products from a pure performance standpoint. But don’t think for a second that Daimler reverse-engineered the I-Shift with the goal of being “just as good.” This transmission – or a version thereof – has been hugely successful in Europe for years, where it was marketed as the Mercedes PowerShift. It has been North Americanized, which is a more ambitious undertaking than you may think, and brought to market very deliberately and thoughtfully. I suspect the decision makers within the Daimler organization knew they’d lose face by bringing forward an AMT that fell short of the high standard that has already been set. That’s not their style.

Of course, only initial observations can be gleaned from an hour-long drive on fairly flat terrain. The real test will come when thousands of these transmissions are deployed in all types of applications right across this continent. It will take years to determine which product best stands up to the rigors of real-world trucking. Daimler seems confident enough that it’s up to the task, backing the DT12 with a five-year/750,000-mile warranty (the clutch is backed by a two-year/200,000-mile warranty).

A potential ace up Daimler’s sleeve is its ability to support the transmission through its Virtual Technician program. Virtual Technician, already available with Detroit engines, sends fault codes generated by the engine or transmission to Detroit’s Customer Center. From there, the code is interpreted by a trained professional and the driver is then advised on the proper course of action.

This is significant because in many cases, a warning light on the dash may not be indicative of an impending catastrophe, and downtime can be reduced by keeping the truck on the road until its next scheduled service interval. That type of real-time support is going to provide customers peace of mind as they familiarize themselves with the DT12.

The DT12 is available in a direct- or overdrive configuration and will initially be offered with the DD15 engine. The maximum input torque is 2,050 lb.-ft. and the gross combination weight limit is 80,000 lbs for the direct drive version and
97,000-plus lbs for the overdrive model. Several customers, including some in Canada, will be receiving demonstration units later this year with full production set to begin in 2013.


Print this page


Have your say:

Your email address will not be published. Required fields are marked *

*