Smart Car, which I think is owned by BMW, has something like this. According to their website, the transmission in the Smart Coupe is an automated manual transmission. It seems to work well for them. It appears to have an automatic clutch as well.
I haven’t driven one of these cars yet, but one complaint about them is a lag in shifting. Smart Car owners say it doesn’t bother you once you get used to it.
@CapriRacer, you wouldn’t need to disengage the clutch at start-up if the transmission is in neutral.
Capri, one of the economy car in China that I mentioned is a Chevy Sail. It’s the opposite of an exotic car. Besides, it’s nothing complicated. Instead of shift shift cables and clutch slave cylinder, it has solenoids connected to the computer.
So a single clutch amt is rougher than a dual clutch transmission. Simplicity and efficiency what economy cars are about. Junior’s fiesta should have a simple transmission. A smooth dual clutch is a better fit for grandpa’s Taurus
“not something a generic Chevy or Ford could use.” @CapriRacer - Ford’s using it in the Focus and Fiesta, VW in the Golf and Jetta.
@Whitey - yes, every review of the (Mercedes-owned) smart car I’ve read complains about the transmission shifting. I’d think they’d have fixed it with better programming, or something.
@texases, thank you for the correction regarding ownership.
I think the delay is just a normal consequence of this type of mechanism. Whether you shift a manual transmission or it shifts itself, you have to disengage the clutch, shift, and reengage the clutch. That takes a moment. This looks to me like a hardware issue more than a software issue. Nonetheless, it doesn’t seem to be slowing sales of the Smart Coupe. I frequently see them on the interstate.
In any case, I think the OP is on to something, even if he’s a little late to the game. This is just the kind of thing that appeals to me, replacing something complicated and expensive to fix with a simpler, less expensive, and more reliable mechanism.
Well, Whitey, I see that you use a computer, why not go back to “something (less) complicated and expensive to fix with a simpler, less expensive, and more reliable mechanism.”
My desktop PC is a very simple, modular, reasonably-priced machine. It’s so simple that if a part fails, I can open up the case and replace the part myself. If the part is something major, like the mother board, I can use the computer for spare parts in another computer, even if it’s not the same brand.
The old fashioned typewriter, on the other hand, is like your automatic transmission, with lots of moving parts. When one of those many typewriter parts malfunctions, the whole typewriter becomes useless. When it breaks, I have to find a specialist to fix it, and pay a lot for the repair.
Are you using voice recognition software, or do you opt for the simpler and more reliable keyboard?
Some of the exotics using automated manuals can execute the shifts incredibly quickly, as can Formula 1 cars. The problem is that those super quick shifts are brutal, hard on everything. A slower shift lets the car use the throttle to get the engine to the right speed, but they feel lazy. A dual clutch transmission can gently disengage one clutch while engaging the other. They’re wet-plate clutches so have a degree of slip as they engage. The main complaint is that the low speed shifts are still too rough. Probably because they still happen a lot faster than a conventional torque converter box. It’s all adjustable with programming, and the very best are apparently quite smooth.
I think it stupid that companies are programming CVTs with discreet gear ratios so they’ll sound more like normal transmissions. The motorboating sound bothers some people. I think they’ll get used to it. The constant rising and falling of a ‘regular’ transmission is just as artificial. We’re just more used to it. I’ve spent enough time in hybrids I don’t even notice engine speed.
Are these dual clutch manual-automatics at least as smooth shifting than the same car equipped with w/a standard manual xmission, the clutch operated by the driver? If so, they’re doing their job. The advantage of the manual automatic is better 0-60 times and better mpg. If the only negative is that the auto-shifting is the same smoothness as you’d get with a driver shifted manual, then what more can be expected? If somebody wants the smooth shifting of a true automatic w/torque converter, and don’t mind the reduced mpg and 0-60 times, well, there’s plenty of cars available of that configuration. Complaining about the smoothness of the shifting of the manual-automatics – provided it is at least as good as a driver shifted manual – seems like it misses the point.
I remember riding and driving cars of the late 1940s and 1950s. I could shift gears more smoothly than the GM HydraMatic drive of that period. In fact, one article I read stated that Chevrolet and Buick developed their own automatic transmission that depended on torque multiplication by the torque converter since these cars (Chevrolet through 1955 and Buick through 1961) used an enclosed driveshaft called torque tube drive and the engineers believed that torque tube drive would just make the Hydramatic even less smooth. I am not certain that this is true since I have ridden and driven Nash and Rambler automobiles that had torque tube drive and Hydramatic transmisisons supplied by GM and these cars didn’t seem any worse than Hydramatic equipped cars with open driveshafts.
The Buick Dynaflow and the Chevrolet PowerGlide (through the 1952 model–in 1953 the PowerGlide did start in low and shift to direct drive) were very smooth and only rivaled by the CVT transmissions of today. At any rate, I would bet that today, even in my advanced years, I could shift a manual transmission as smoothly as the new manual-automatics.
Triedaq , I’m sorry but with my '09 Dodge caravan, I can only tell when my transmission shifts from 1st to 2nd by the sound and can barely hear the sound as it goes from 2nd to 3rd to 4th and converter lockup. Now maybe it is slipping, but it has been this way since I got it with 46K and now has 65K.
BTW, I had a new '53 Buick Special with Dynaflow. I also had a '54 Hudson Hornet with Hydramatic and I don’t remember it shifting rough. I also had a '56 Dodge Momoco, a '68 Chrysler Station Wagon, a '73 Chrysler Newport, a '78 Chrysler new Yorker, an '83 Dodge 1500, a '90 Plymouth Voyager, a '93 Caravan, a '94 Dodge 1500, a '96 Dodge 2500 Van. I had no problem with them and never notice any of them shifting rough!! I did have to add some Berryman B12 to the '96 occasionally to keep it form sticking in 2nd. So you see, I have been happy with my automatics.
Elly, if you are happy with your automatic transmission as it is, good for you. But there are other drivers who prefer the direct response, efficiency, and robustness of a manual transmission but have to share the car with someone else who have no business driving a manual. AMT is the best compromise so far.
My next car will probably have an AMT, if my wife insists on an automatic.
One problem I hear about the CVT driving experience is that when the driver presses his/her foot on the gas, the engine revs up more than expected, and the speed of the car just seems to increase slightly. So it feels like the CVT acts as sort of like a sponge, preventing the car from accelerating as fast as the driver would expect.
I’m guessing this is because the CVT downshifts slightly when it gets a big power increase input. Automatics do this too, but you really have to punch the gas to make it happen. And it is annoying in automatics when it happens and you don’t want it to. LIke if you just want to gradually accelerate from 55 to 60 without downshifting, but it downshifts anyway. So if it happens most everytime you step on the gas with a CVT, I could see how the driver might complain about it.
I don’t think they really needed to program in shift points to sell the cars, since large numbers of cars with cvts were already selling, but it was something very easy to do that probably convinced a few more buyers. Personally, I think it’s just something minor to get used to. The up and down rpm action of a ‘regular’ automatic doesn’t sound any more natural, it’s just what people are used to. The cvt effect of the engine speed not being related to vehicle speed is known as ‘motorboating’ (a cool, apt term). So you step on it, rpms climb much faster than vehicle speed, and then end up dropping as the vehicle accelerates. Good sound insulation is the easiest solution. Programming in ‘gears’ is another, but at a slight cost in either performance or efficiency.
GeorgeSanJose " I'm guessing this is because the CVT downshifts slightly when it gets a big power increase input". The trans is not downshifting, it is just slippage in the torque converter. It is normal and should be expected and not to worry about.
It’s sometimes more than a slight downshift. To be really efficient and give good performance many cvt equipped cars downshift dramatically when you accelerate hard, sending the rpms soaring. A cvt lets the automaker use a smaller engine and still get adequate performance. That increase in rpms isn’t what bothers drivers, because a regular auto might downshift, too, and even if it doesn’t the engine is going to speed up as you stomp on the gas. It’s what happens next that feels funny. The car continues to accelerate, but the engine speed starts falling as the car no longer needs as much power as it did at first. It’s that apparent contradiction that seems strange. Of course, the same happens in any other car, but in discreet drops as the car shifts. Since that’s ‘normal’ it doesn’t bother us. Programming in the stairstep effect of ‘shift points’ makes the car sound more normal, at some minor cost in efficiency. After a few minutes in a cvt-equipped car I don’t notice its behavior, either.
Good post @NSUTT … followed your advice … for others interested, here’s a link to a Wikipedia page about VW’s Direct-Shift Gearbox. It has a good photo, a cutaway of the innards, which you can enlarge and see the details of the inner workings.