Attention: TDR Forum Junkies hasselbach said:
I really appreciate some of these observations, since I would like to get a Jeep Rubicon and continue to wrestle with the manual / automatic question. My application is ranch work and hunting; I am not interested in the extreme applications involved in negotiating the Rubicon trail. I conceed that a manual can apply shock loadings that an automatic won't in a situation like the Rubicon trail. But intelligent operation of a manual in my application isn't going to be more stressful than an auto. And a manual doesn't have all that wiring and electronic stuff. A little water gets in that wiring harness connecting the engine managment computer to the transmission and you've got problems. Or a little vibration weakens the connectors. Gears attached to a stick don't have these problems. But if autos have a good record on the Rubicon, I'll bite. I have to consider my wife's preference too, and she likes an auto.
At slow speeds off road, a properly geared manual can lock up sooner than most current autos and achieve efficiency gains. I consider this significant only when towing heavy loads and where the TC doesn't lock up. Certainly, autos, can and probably will continue to evolve to eliminate this advantage. One reason the Allison is so popular, is because it locks up 2nd through 5th and consequently almost perfectly duplicates the braking and efficiency advantages of a manual without the disadvantges of a clutch. Unfortunately, it is connected to a Duramax. But for now, if you want a Cummins, the 48re just doesn't have these advantages at all rpms and in all gears. Not to mention the subject of exhaust brakes. Let's face it, the 48re just doesn't do enough yet to make the 6sp obsolete. I think the moment it does, no one is going to care if a little more No. 2 is burnt, or an extra row of tubes has to be added to the radiator.
For all those folks all hung up over efficiency, the question is not the absolute losses of an automatic, but the differential between the two systems. In the case of my Corvette, it is well documented that in the case of the manual equipped car, rear wheel horsepower is 82. 5% of crank horsepower. That's a lot of loss for a mechancially locked system! Sure some of it is engine driven accessories, but most of it is lost in the drivetrain, which is why Mallet added a manual transmission oil cooler. I don't recall the numbers for the auto in a Corvette, but they weren't much different. Both sytems have losses, just, as you have pointed out, from different sources.
The addition of lockup clutches to torque converters should settle the TC slippage argument. For the most rapid possible acceleration, slippage serves a purpose, so long as power is cheap. For efficient acceleration or constant speed operation, slippage is a waste. When power costs a lot or is limited in amount, you have a situation like peddling up a hill on a mountain bike. Would you want to do that with a fluid coupling? If you need torque multiplication, you add gears, not a fluid coupling, no matter how efficient. If slippage was so good, there would be no TC lockup.
Finally, with the broad torque range of today's diesels, the efficiencies are debateable. Is there more loss operating at various points within this band or more loss in the TC slippage? Due to the variables involved, the question can only be answered by testing the same vehicle with the same engine using automatic and manual drivetrains. Right now, manual cars still get better mileage. Electronically controlled valve timing will make engines efficient as well as powerful over a broad RPM range. TC's designed to allow engines to operate at a constant speed may then not offer enough benefits to justify their costs and complication. Manuals could be around for a while.
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), or tell fellow members to 'go get an education' and come back if you want to discuss something. We don't try to belittle eachother's knowledge like you have above. It's also interesting that you go off on everyone about how educated you are and how nobody else is, and then you make simple spelling/grammatical errors in your posts repeatedly. I recommend going to the dictionary and looking up the word tact, and the word friendly. I suggest you try applying some of those techniques. The members here for the most part treat eachother with respect and as if they were friends. Picture yourself acting so arrogant in person with this community... (as we all picture your trip to the hospital). . Sure you can try to flip my comments as you did earlier, by saying I'm antagonistic with this post, but I'm not. I'm simply pointing out your behavior is out of line here, and you won't make many friends with that kind of elitist attitude. In my experience however, TDR people are very kind, and likely will give you a second shot, should you attempt to provide the facts in a non aggressive manner. . 
