Sunday, March 11, 2012

Automatic Transmission versus automatic transmission

Within the aviation community there's a spirited debate about the term conventional landing gear. Traditionally, the term refers to taildragger airplanes, those that have a tailwheel, like a Piper Cub, the Boeing B-17, and the Douglas DC-3. But since around the time of World War Two most aircraft have been manufactured with "tricycle landing gear" or a nose gear. Almost every airplane you see today is a tricycle with a nose gear; short of Homebuilt or other purpose-built aircraft (e.g., agricultural, aerobatics) you would be hard-pressed to find many airplanes with a tail wheel.

Yet despite the fact that most aircraft manufactured within the last half-century use tricycle/nose gear, the term "conventional landing gear" continues to apply to the tail wheel. This is confusing to people new to aviation; to them "conventional" is what they see out at the local airport every day like the Cessnas and Cirrus, or every airliner they'll board, all of which have nose wheels. Yet that traditional term persists.

So it is with automatic transmissions in cars today. Mention "automatic transmission" to me (I'm approaching a half-century myself) and I immediately think of the old GM Hydramatic transmission, with a torque converter, an internal pump, clutches and bands, a valve body, etc.Those are truly your father's automatic transmissions, the one where you moved the lever from "P" into "R" then "D" and then never touched it again except to put it back in "P" when you got home. Push the accelerator pedal to go; push the brake pedal to stop, no clutch pedal or shifter required.

On the other hand, mention "automatic transmission" to someone just learning to drive, and their mind may not necessarily turn to torque converters, valve bodies and such; they skip all those technicalities and go right to thinking "how do I go and stop, and do I have to touch the shifter again until I'm home?" Yet it's quite possible that these new drivers are learning in automatically-shifting cars that, from an engineering perspective, have much more in common with the old "4-on-the-floor" than they do with Granddady's TorqueFlite.

We still call these new technologies "automatic transmissions". But are they, really? What makes a transmission an "Automatic"?

Is simply the lack of a clutch pedal that makes something Automatic? If so, then what about the Formula One cars that do not have a clutch pedal, instead using an electronic button on the back of the steering wheel to activate the clutch? And what about before that manual button was required by the regs and they let the computer activate the clutch? Would you say that Formula One cars were/are using Automatic Transmissions?

Is an Automatic Transmission defined by a lack of a stick/shift lever that has to be rowed to manually select gears? If so, then that would again support the idea that Formula One cars use Automatic Transmissions, given their gears are selected using electronic "flappy-paddles" on the steering wheel instead of a shifter.

But if a Manual is all about having a clutch pedal and shift lever, then what about World Rally Championship cars that have sequential-shift gearboxes that don't use a clutch between shifts? If you don't have to use the clutch to shift, is that an Automatic? What about prior to 2011 when WRC cars were allowed to use those "flappy-paddle"selectors for their sequential-shift boxes instead of a gear lever; did Sebastian Loeb win numerous WRC championships with an Automatic Transmission?

But if the method of the engine engagement and how gear are selected  and a clutch pedal and shift lever are not needed to be considered Manual, where does that line cross to being considered Automatic? VW's DSG and BMW's SMG (as well as many other high-end super cars) use "conventional" flywheels with clutches, and internal gears and synchronizers. Yet none of them have that third pedal, all use computer controlled solenoids to engage/disenage the clutch and select gears. All have some form of manual over-ride giving the driver ability to select the desired gear, with computer backup to avoid human error such as the dreaded 3rd-to-2nd "upshift". But so did the Turbo Hydramatic...

If you contend that ones does need a clutch pedal, a shift lever, and one must be forced to move that lever and clutch pedal between shifts, is the Ferrari Enzo with the flappy-paddle an "automatic transmission" car? If gears/syncros, a shift lever, and a clutch - but no clutch pedal - are all required to be considered Manual, what about the old VW/Porsche  Sportomatic, where the conventional clutch was operated by a vacuum solenoid, actuated by vacuum switches mounted at the base of the shifter?

And how do CVTs (Continuously Variable Transmissions) fit into this mix? What about pure electric vehicles that may not have any gears at all?

Automatics have historically suffered from disdain within enthusiast communities because of their lack of sportiness. They typically had fewer gears than manual transmissions and the torque converter, pumps, fluids, bands all robbed efficiency from transferring power to the tires. Automatics also received disdain from motorists interested in efficiency, as they almost always had relatively-poor fuel economy for all the same technical reasons. But automatic transmissions were easier to drive and demanded less from the motorist, so their popularity has consistently increased.

Today, technology is blurring the lines between the traditional/conventional ideals of Automatic and Manual Transmissions. With the newest technologies of automatically-shifting transmissions, both the enthusiast and efficiency fans are finding these new designs meet both their needs, and more manufacturers are offering them to improve fleet fuel economy.

But are these new technologies really Automatic Transmissions? So what does define a transmission as "automatic"? Is it the technology in the box, or is it how the driver interacts with the machinery? Just as debates over "conventional" versus "tricycle" landing gear continue, I suggest the debate over what makes a transmission "standard" or manual or automatic or big-A Automatic will rage on. I also suggest that within the performance enthusiasts' mindset, the presence of a clutch pedal may be the milestone between automatic and manual transmissions (though they'll conveniently ignore their favorite super-car's flappy-paddle no-clutch-pedal gearbox). Regular motorists will likely make that same distinction, that being the absence of a clutch pedal and the ability of the car to pull away from a stop and shift without driver intervention.

And me? Being the motorist/enthusiast/racer/engineer that I am -- and a new, unabashed fan of Volkswagen's DSG -- my differentiation will go right back to the old Hydramatic transmission, with the emphasis on the "hydra" part. In my mind, if engine torque is transmitted through a hydraulic fluid via torque converter, bands, and valve bodies, I will forever consider it to be an Automatic Transmission. If power is transmitted through a flywheel, clutch, and meshing of gearsets, it's a Manual Transmission, regardless of how those mechanisms are engaged. I'll gladly let my street car automatically pull away from a stop and shift the gears for me, but I demand the ability to over-ride the computer and shift it myself.

These new technologies are pretty good, so good that someday I predict we will mourn the death of the good ole clutch pedal; those driving skills will eventually go the way of the manual choke and spark retarding, and the hand-cranked starter...

GA