Having previously driven the amazing combination of the Detroit DD15 engine and Detroit DT12 automated-manual transmission (AMT) in my Freightliner Cascadia Evolution prior to getting my current CNG setup, I didn’t think I would be able to get my hands on another AMT any time soon.  Being that the AMT is not offered with the Cummins ISX-12G natural gas engine, I have instead had the privilege of driving with a fully automatic six-speed Allison 4000.  As awesome of a product as the Allison is, I would be lying if I said I didn’t miss the DT12 AMT after I finally had adjusted my driving to use it to its fullest potential.  By accident, I now have found and bought another AMT to fill the void that my past DT12 left me with…sort of!
 
While looking for a new little commuter car to get back and forth to where I park my truck this past weekend, I test drove a Smart ForTwo.  Not usually being one for small cars, I was slightly standoffish from the idea of driving something so small on the road.  I took a test drive and learned a lot about how Daimler has incorporated not only fuel efficiency, but also a great deal of safety into these tiny commuter cars.  During the test drive I was thrown off by the way the automatic transmission moved its way through the gears.  In the Smart ForTwo, there was not the usually “slurring” through gears you get with most standard automatic transmissions, as they smoothly go up and down through all the gears.  Instead there was a lag in between gears, which at first had me wondering if the transmission was broken or low on fluid.  Low and behold, with a little research post-test drive, I found out that the reason it did this was because the ForTwo is equipped with an AMT and not a true automatic transmission.  This “smartshift” transmission shifts-by-wire and allows the Smart to achieve a 7% efficiency gain over a true automatic, similar to the truck efficiency gains seen in trucks using the Detroit DT12 AMT.
 
It seems that the first impression of AMT’s is not all too far off in the four-wheeler community than in typically is in the big truck world.  Most people are not used to driving these types of transmissions and are not as receptive to letting the transmission work as it was designed.  In both the auto and big truck communities, most seem to get frustrated by the actual shifting of the vehicle and are more likely to just put it into manual mode and try to shift all the gears themselves.  This is the wrong way to go about driving an AMT from an efficiency standpoint, as you are not letting the technology be as efficient as it was designed to be.  Nowhere is the “brainwashing” of automatic transmissions more apparent than in the auto world and likewise are the drivers less likely to want to re-train their brains to drive an AMT.  I am excited that a car company has tried to go against the grain and bring an AMT into a car, even if it is touted as “sluggish” and “inconsistent” by a lot of reviewers.  Remember, that whether in a big truck or a small car, getting the most out of your AMT comes down to your willingness to change and adapt your driving style to maximize the efficiency of the vehicle in the way it was designed!

Comments (2)

Jimmy Nevarez

Jimmy Nevarez is the Owner/President of Angus Transportation, Inc., based in Chino, California.  Jimmy pulls a 53' dry van hauling general dry freight for his own small fleet, operating on its own authority throughout all of Southern California and Southern Nevada.

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I am glad someone brought up VW's! Other than my newfound love for the Smart ForTwo, VW blood runs through these veins. I owned the generation of Tiguan that was post-DSG, several newer Jettas, and currently a Touareg. You are correct in the similarity between the "SmartShift" and VW DSG In that both result in the elimination of a traditional automatic transmission's torque converter. The dual-clutch of the DSG however is much smoother in operation and feels more like the "smooth" shifting of a traditional automatic. In the "SmartShift", the gear changes are much more noticeable and jarring to anyone who has not driven a true AMT before. Some people have even tried working around the "rough" shifting (under recommendation of techs, sales people, and Smart car forum comment fodder) by trying to let off the gas just before shifting, which in actuality defeats the purpose of the efficiency that these were designed for.

August 13, 2015 19:16:18 PM

VW, has had a Direct Shift Gearbox or DSG for a few years now, it is an automated manual. I think we will see more and more of these making it into cars as well as trucks. I believe in the VW application that the DSG equipped cars have a slightly higher EPA rating that with a manual gearbox, the computer is able to squeeze more out of the DSG than a driver can in shifting.

August 12, 2015 23:09:47 PM