Hello,
can you explain how these things work? Not necessarily from an engineering standpoint but from a “I only know how to drive automatic” standpoint. Do you change gears, but just skip the clutch part? Do you have to change gears? Can you choose to change gears sometimes and not at other times? What about ones that have the paddles on the steering wheel, such as Sportronic CVT with INVEC-III on the 2008 Lancer from Mitsubishi? Thanks.
They’re automatic with no manual combined. They simply let you select the automatic gear you want without letting the automatic select the automatic gear you want. Automatics in general really combine two things for you – which gear to be in, and getting into and out of gear.
There are a bunch of different ones. A basic kind often allows you to select either automatic or semi-manual with a button. When it is in manual mode, you just move the gear selector through the gears as you want with no clutch required. The basic idea is built into most automatics. You can shift most automatics if you want to by starting out in LOW (or 1) and moving up through the gears if you want extra engine RPM’s. It isn’t the same but it gives part of the functionality.
Ok, so you get to choose how you want your transmission to work basically?
In winter driving I often have to shift up and down so I understand when to shift and the IDEA behind manual, I have just never had the opportunity/need to learn it. I have only bought cars from family members in the past, and they have all been manual.
There are two types of clutchless (as in the pedal) transmissions.
There are automatics that have a ‘manual’ mode such as BMW’s Steptronic, Chrysler’s Auto-stick etc. A lot of cars have this now. The lever can be pushed forward or pulled back to shift the gears effectively overiding the standard automatic behavior. Realize however that this is still an automatic tranny with a torque converter, not a clutch.
The other type is a true manual gearbox but with no clutch pedal. Instead, the clutch is controlled via a computer which reacts to the lever movement. This is generally known as an electrohydraulic manual transmission. Like the auto, you shift up in one direction and down in the other. There is no ‘gate’ like a true manual. The most widely used is the BMW ‘SMG’ box (sequential manual gearbox) which actually wasn’t that well received. Several really high end brands like Ferrari have their own electrohydraulic transmissions.
With both types, you can get the ‘flappy paddles’ on the steering wheel. These simply mimic the actions of the shifter. Some only have the paddles and no floor shifter.
This reminds me, I only have limited experience actually driving cars with these manual-override automatic transmissions. Does anyone else find them as completely useless as I do? I drove an Eagle Talon (Chrysler) years ago, and probably just didn’t know how to take advantage of it. But recently I drove a Mondeo for almost an entire year with this feature. The only differences between it and a standard automatic (how do you like that verbage?) were
[ul]
[li]I could downshift without accellerating (i.e., use the engine for braking)[/li][li]Prevent it from upshifting during accelleration. It’d hang just before redline with no useful purpose.[/li][li]It refused to downshift if downshifting would have surpassed the redline.[/li][li]It would automatically downshift if the engine were severely lugging due to having slowed down.[/li][/ul]
It was a V6 (I don’t know what size; 2.4L to 3.0L I imagine). The only conceivable, quasi-useful thing I could use the shifter for was slowing down without having to light up the brake lights. 
(By contrast, even the 4-banger, 5-speed manual Fusion that I got to play with once in a while was much, much more fun, and snappier, too.)
When you up shift an automatic or one of the auto-sticks or paddle types that over ride the automatic tranny, you are not actually shifting…
…you are giving permission to the transmission to accees the next forward gear.
There are some minor exceptions, such as some vehicles that let you start in 2nd gear, but for the most past, those automatics that have some type of manual tap shifter or paddle shifter over ride don’t let you upshift.
Some don’t even let you down shift if the conditions are such that you’d over rev the engine by selecting too low a gear for a given speed.
So, if you are driving 35 MPH and upshift to say, fifth, the car probably won’t upshift, but you’ve now given it permission to upshift as high as fifth. And there are some that won’t let you shift down to first if your are doing 50.
You could actually do most of this with a regular automatic tranny anyway. The new styles have more computer control and some over-ride features working in conjunction.
Add to MrFloppy’s list is my MINI’s transmission. It’s a CVT (continuously variable transmission) with a manual override option. The 6 manual “gears” are software-based, pre-set gear ratios the belt will go to on command. It kinda defeats the purpose of CVTs, but my wife uses it during hard acceleration, I just press the pedal down more.
It can be quite handy when driving in the mountains. Both climbing and descending. Even modern brakes are taxed to extremes when descending long grades unless you downshift to provide some engine braking. When climbing, a normal automatic won’t downshift unless you apply full throttle. You then reach desired speed, back off the gas, and the automatic up-shifts. But the engine can’t provide enough power in the higher gear (at less than full throttle) to maintain speed, so you apply more gas, forcing another downshift, lather, rinse, repeat.
If you can force the transmission to stay in one gear, you can avoid this cycling. Often the engine WILL have enough torque in the higher gear at full throttle, but if not, it is more economical and less wear and tear to stay in the next lower gear using only perhaps 2/3 to 3/4 throttle. The second option is available on all automatics (those numbers beyond “D”) but the first is only available on the newer manually controlled autos.
Beyond mountain driving, it might be desirable to delay an up-shift when merging onto a freeway for example. By staying in the lower gear, spirited acceleration is available without the second or so delay needed for a normal automatic to downshift.
Many, if not most, drivers who prefer automatics can’t be arsed to bother with this. These are exactly the sort of reasons, though, why people who prefer manual gearboxes have such preference. Especially American auto companies would prefer to quit making manuals, (It’s a smaller market, and slightly less profitable) and the newer gearboxes are an attempt to keep the clutch stompers on board while only producing the single slushbox equipped product preferred by the majority.
Another reason for this setup is that the “fully automatic” mode can be programmed with a shifting profile for best fuel economy, and demonstrated for the CAFE testing. The driver who wants the performance of delayed shifting can drive it that way, yet default to the economy profile when appropriate.