OK, first of please leave the ‘three pedals or your manhood/ovaries will shrivel up discussion to the 375,000 other threads on exactly the same topic. Instead, where do we think the future is for automotive transmissions? We’ve had some form of automatic transmissions in cars since, it could be argued, the model T. Fluid flywheels came along in the 30’s, preselector were quite common in the 30’s and CVT’s pre-date the automobile.
The only reason that F1 and sports cars didn’t use fluid flywheel autos was because they were banned as they have some massive advantages in torque multiplication and speed of shifting if that was your development goal. Chaparral was using auto boxes before they were banned in CanAm. Really the only reason Ferrari developed the ‘Semi-Automatic’ trans for F1 is that both auto’s and CVT’s were banned. Ditto Porsche and Audi before Ferrari were experimenting with PDK transmissions in Group C sports cars and Group B rally cars.
So Ferrari, Porsche etc. brought variations flappy paddle shifted manual transmissions which have broadened in scope and use while others concentrated on regular torque convertor boxes (Jag, Merc etc.) with locking convertors and electronic control. Where does the future ultimately lie? Manumatic boxes now have shift times that make blinking seem like a long drawn out process. Regular autoboxes can now mimic a flappy paddle box with full lock up when they want it, rev matching shifts etc. Where is the future? A regular manual may be theoretically more efficient, but full autos are now ridiculously efficient and still have advantages on being able to slip using the torque convertor for around town and maneuvering without wearing out expensive clutches and still have the advantage of torque multiplication within gear and have essentially instant shifts. We now see 10 speed auto’s that can in effect act like CVT’s. Will we ever see a CVT that can live up to its theoretical advantages that is production efficient.
I don’t’ know the answers, I’m not a transmission engineer so I don’t’ know the current technology or what’s coming well enough to make an educated comparison.
three pedals or your manhood/ovaries will shrivel up
I think the tried and true fluid couple planetary gear automatic will continue to be the go-to. It has progressed to the point of being almost indistinguishable from DCT/manumatics for 99% of the people who would drive one, and it's should be cheaper to produce based on the millions of units they have already spit out over the last 60 years. It's probably smaller and lighter to package as well (except for the torque converter full of liquid).
I am not a transmission expert either so that is pure speculation that is quite possibly totally inaccurate. 
The only reason I can think the planetary set up is inferior to the dog/gear set up is the fact that the planetary gears need constant oil flow to keep the bands tight.
Other than that, the planetary set up allows for a much smaller package, which allows more gears- mimicking a CVT closer.
The only reason DSG's are bad is the clutch and the feel of the clutch engaging. Other than that, they are very durable and shift nicely. Oh, and don't mix DSG and manuals- even though they use the same mechanism, DSG's allow for better ratios in terms of fuel economy- since they can downshift when doing certain measures.
Manuals are always stuck with bad ratios, as the top gear performance tests are always done WITHOUT a downshift. Give them the ratios that autos get, and I think they will be back to being superior just because of efficiency.
What I do see- the Honda Insight style flywheel coming back. For a "mild" hybrid set up. (no real sight, just what I think will come back)
In a logical world the CVT would replace the planetary automatic in non-performance applications within 5 years, and the robotized manual would be the standard in performance applications.
But because illogical consumers demand that everything should feel like a slushbox, forcing CVTs to use stepped shifting and DCTs to use gear blending and clutch slipping to simulate them, Huckleberry's right. The bad ol' slushbox will reign until gearboxes in general become a niche item.
Not sure, but if the current crop is any indication, sure hope CVTs fade out like 8 tracks did.
I see everyone trying to reduce engines running in transient rev ranges as much as possible. Building an engine that runs at a few set RPM's utilizing some sort of transmission to move things.. Sort of like a Genset.. 1 rpm.. spin genny.. use electric motor for wheels.
^That's how the hybrid model of the BMW i3 works.
In reply to Fueled by Caffeine:I was going to post that. Our hybrids run that way and they've been very reliable with half the ICE that conventional diesels buses use .
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That's an interesting thought. Run it like a diesel train. Engine drives a generator and has a few set RPM points it can run at based on power demand and then use electric motors to actually move the thing.
So when cruising on the highway, the engine may sit in something like "notch 2" at 1500 rpm, but when you hit a hill and the power demand goes up, it'll step up a notch or 2 to maybe 2000 or 2500 rpm to meet the increased power demand and then step back down when the power demand is reduced. Going down the hill where the power demand is very low, it might just drop to idle where it's only making enough power to keep the electronics running, etc.
GameboyRMH wrote:
In a logical world the CVT would replace the planetary automatic in non-performance applications within 5 years, and the robotized manual would be the standard in performance applications.
I've heard a lot of reliability problems with almost everyone's CVTs. Maybe they're not all they're cracked up to be. Efficiency might be better but if it's not paired with reliability then there's no contest which I would choose.
I meant to keep this to primarily internal combustion driven vehicles. The small high efficiency engine to run electric motors is probably the way forward, but keeping this to I/C engines is what I meant.
I think the biggest thing holding back traditional automatics at this point is perception. The elite automakers will keep with automated manuals, but modern automatics are amazing and I think could replace automated manuals if allowed.
I see pure ICs as low-cost, low-power solutions after about 10 years from now.
That to me says a motorcycle-style sequential will predominate - it'll have the same hardware between "manual" and "automatic" versions, is at least as efficient as an ordinary manual, and is probably the lightest and cheapest way to get multiple ratios.
In reply to rslifkin:
It would more likely only have idle and run speed settings. Throttle position would hold it at the run speed under different load levels. As the load increases the throttle will open to hold the RPM. The generator would almost certainly be an AC unit, and it would be designed to run at a specific frequency, which correlates to a specific RPM of the generator armature.
The speed of the drive motor, or motors, would be controlled by varying the frequency of the 3 phase AC fed to the motors.
Back to the subject of transmissions: As a consumer I'd prefer to have a well refined torque converter/planetary gear traditional automatic transmission if I can't have a manual gearbox.
I can see a place for CVTs on lightweight econo-cars, but it's a fools game to insist on putting them in SUVs and bigger sedans. (I'm talking to you Nissan).
Personally, I'd like to see something with a constant mesh sequential manual like a motorcycle gearbox, but I know I'm wierd.
Honestly, as long as the slip-mechanism locks up solid in manual mode at anything above a minimum (stalling) rpm threshold, I don't care whether it's a torque converter or a pair of clutches doing the job. In auto mode, either can be made to work equally well, but its certainly easier to do with a torque converter.
At this point in time, from a purely driving perspective I think transmission programming and public perception has more to do with it than anything else...Although my experience to date is that torque converter units are more likely to be programmed to not hand over full manual control to me than dual clutch.
At this point, I'm not sure which has the theoretical efficiency advantage anymore. So all else being equal, I'd simply rather it go in favor of which ever is more reliable and less complicated/expensive to maintain/repair over the life of the vehicle...Which means it'll probably go the opposite way.
What are the realities of the transmissions at this point?
I have almost no experience with automatics; none of my project cars have ever had one, and my van is the only vehicle I've owned with one. My ignorance leaves me with the notion that autos are heavier than manuals. My limited experience with my family's cars (ancient Fords) and rentals was until recently that automatics were awful from a tactile standpoint because of that mush of the torque converter.
Then a couple of weeks ago I drove a late 328i rental, and it didn't feel mushy at all, and the manual-mode shifts were very quick. I didn't get to play with it much, and was driving it like I was driving someone else's BMW in urban commute traffic (because I was), so incomplete impressions. But the behavior of this trans seemed excellent; I wonder how heavy/large/complex it is compared to the manual, and from a pondering-for-say-autocross standpoint, how heavy the rotating bits in particular.
I guess the upshot is that I share Adrian's question, and need to know more about the realities of modern transmissions of each type to have an actual opinion.
Automatics are heavier than traditional H-pattern manuals, which are the lightest. CVTs are similar in weight to an automatic and dual-clutch robotized manuals are the heaviest.
I like the transmission-less Accord hybrid design.
The engine turns a generator that powers the electric motor. Once up to a certain speed, a clutch engages the engine to the final drive. It's pretty slick.
The Koenigsegg Regera works in a similar fashion.
I think more and more will be like the Prius/other hybrid CVT. Single or dual planetary setup with one or two clutches. Dual electric motor input, single ICE input. Very very simple and reliable.
Spoolpigeon wrote:
I like the transmission-less Accord hybrid design.
The engine turns a generator that powers the electric motor. Once up to a certain speed, a clutch engages the engine to the final drive. It's pretty slick.
The Koenigsegg Regera works in a similar fashion.
The Regera actually has a hydraulic transmission, something like the front drive on 2WD motorcycles (although it is still a power-split hybrid).
These are interesting times. We're seeing less and less follow the leader in the auto industry. I think we're going to continue to see, CVTs, PDKs and 10 speed or more autos along with the rare manual as the industry transitions to driverless CVT hybrids and pure electrics. I don't think that we're going to see another period where there's a common drivetrain that you can pretty much count on like the ubiquitous three speed Simpson geartrain autos used from the '60s through the '80s till we settle on whatever soulless pods we're headed for.
This all bring up another point. If you have manual control, be it three pedals or some form of DSG/PDK, is there much point in going past six gears? It seems to me that unless you have a Hamilton or Alonso at the wheel all you will do is guarentee the car is in the wrong gear 99% of the time. With traditional autos we're up to 10 forward and 2 reverse gears. With PDK's I think we're up to 7 forward now. Is there any point in that for the steering wheel to seat back spacer? I can toally see the efficiency with a computer in charge though for 10 speeds.
In reply to Adrian_Thompson:
For any auto past 6 gears- one must look at how many ratios are normally used. Many skip.
Adrian_Thompson wrote:
This all bring up another point. If you have manual control, be it three pedals or some form of DSG/PDK, is there much point in going past six gears? It seems to me that unless you have a Hamilton or Alonso at the wheel all you will do is guarentee the car is in the wrong gear 99% of the time. With traditional autos we're up to 10 forward and 2 reverse gears. With PDK's I think we're up to 7 forward now. Is there any point in that for the steering wheel to seat back spacer? I can toally see the efficiency with a computer in charge though for 10 speeds.
Big rigs have manual control and have 15ish gears.
