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  #1  
Old 11-30-2016, 10:40 PM
Dmanosaka Dmanosaka is offline
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Benefits of auto shifting

Hi everyone, My soon to own 320i has the shift option like so many other models. I've never shifted an automatic. Is this really a desired feature or just a bauble? Is there a performance gain? Since it won't redline and prevents damage I wonder about its usefulness. All experiences welcome. Thanks.
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  #2  
Old 12-01-2016, 02:53 AM
Kryten Kryten is online now
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Mostly lets you have some control over gears. I've tended to only use it in a couple of situations:

1. Spirited driving where I want to down change before a corner or before passing etc.
2. In snow where I want to force a car to drive off in a higher gear to reduce torque at the wheels.
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  #3  
Old 12-01-2016, 04:56 AM
Dmanosaka Dmanosaka is offline
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All for spirited driving. (^_-) not much snow here but good to know. Thanks for that.
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  #4  
Old 12-01-2016, 05:03 AM
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Doug Huffman Doug Huffman is online now
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Automatic gear selection is consistent to deliver the designed performance benefits, be they economy, or minimize stress on the drivetrain. Automatic shifting cannot anticipate the future wants of the driver. The various automatic shifting modes may optimize particular aspects of performance. There are other automatic dynamic systems for peculiar driving conditions.

My X5 xDrive ZF six-speed will not 'force' my desired gear.

I manually shift to maximize certain other aspects of engine performance, to wit, maintain rpm >2k for DPF regeneration.
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  #5  
Old 12-01-2016, 05:05 AM
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Doug Huffman Doug Huffman is online now
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Quote:
Originally Posted by Dmanosaka View Post
All for spirited driving. (^_-) not much snow here but good to know. Thanks for that.
Is not Japan in general having its snowiest November of the previous half-century? Could'a sworn I saw that headline.
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  #6  
Old 12-01-2016, 05:25 AM
Dmanosaka Dmanosaka is offline
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I'm looking forward to giving it a try. Probably I'll keep stepping on the phantom clutch pedal. I'll adjust.
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  #7  
Old 12-01-2016, 05:25 AM
Dmanosaka Dmanosaka is offline
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Not in Osaka. We the south. Lol.
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  #8  
Old 12-01-2016, 08:04 AM
Kryten Kryten is online now
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Quote:
Originally Posted by Dmanosaka View Post
Not in Osaka. We the south. Lol.
Lucky you, was in Tokyo a few years back in a January and they had quite a lot of snow Never made it down to Osaka area, next trip maybe.
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  #9  
Old 12-08-2016, 01:03 PM
Glaird Glaird is offline
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I'm an old timer, who use to race when cars were real (meaning they had manual transmissions that required a clutch and the knowledge of "double clutching"). I have pondered this very question. I now have a 2016 550i, with 3 shift modes; fully auto, sequential bumps on a stick (very much like a motorcycle transmission), and paddles on the steering wheel. Here is what has gone through my mind, or I have experimented with:
1) For maximum acceleration, there is no way to beat a full auto tranny. Ergo, F1 now uses paddle shifters, coupled to an automatic. Even a fast driver, with a clutch and a stick, there is a measurable delay between upshifts.
2) For maximum deceleration, such as approaching a corner in a race, we use to combine downshifts w/brakes. Well, brakes have vastly improved. But, if you want to be in the right gear, upon high speed exit from a corner, one needs to manually hunt for that gear. I have found paddles are clumsy, difficult to find while turning, and have latency in execution. Bump down shifting of the lever, as on a motorcycle, achieves the proper gear selection; but, is not needed for deceleration.
Then again, if one just stomps on the gas, at the apex of a corner, in full auto, the transmission will figure out and select the correct gear in the same amount of time or faster and smoother.
3) So what does this manual selection of gears accomplish, for a performance driver? In snow, as stated above, it allows the driver to lug the engine, to avoid wheel spin when negotiating slippery surfaces. In a race, it accomplishes nothing, that a full automatic won't do quicker. For the fans on the side of the road, bump shifting may raise the driver's cred with his fans, because it allows the driver to time the exhaust note.
4) Well, there is a place where I found bump shifting very convenient; commute/dense traffic. It allows me to moderate my speed/cruise at slow speeds, by selecting just the right gear for enough engine drag, yet still have enough room in RPM to accelerate momentarily as traffic ebbs and flows.
5) Without the admission of violating any vehicle codes, there is one other place that bump shifting (or paddles if that is all there is) comes in real handy. That is suddenly overtaking a traffic cop, wanting to quickly and discretely slow down, without flashing horrifically bright tail lights that lets the entire world behind you know what you have just done. Plus, since the deceleration acts on the rear wheels only (assuming we are talking about BMWs), the car will squat as it decelerates instead of pitching forward. The latter, to an experience patrolman, is a dead give away that you are braking.
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  #10  
Old 12-08-2016, 02:54 PM
Dmanosaka Dmanosaka is offline
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Double clutching. Lol. Haven't heard that in a very long while. Thanks for your insights. Especially number five. Great advice. I like the convenience of the automatic but so miss pushing to the red line on occasion. Hard to find manual transmissions in Japan. I'll give the auto shift a try. We've lots of traffic daily. Might be what I need. Cheers.
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  #11  
Old 12-08-2016, 04:00 PM
Glaird Glaird is offline
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I, as well, really miss a manual transmission high performance car. Alas, as I get to the point where I can actually afford to play with such vehicles, that I dreamed of owning for most of my life, life frailties and marketing realities are setting in place. Either no manual option is offered. Or, I have to think of the possibility that my wife or I might not be able to operate the car one day, due to disability, injury, or illness.
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  #12  
Old 12-08-2016, 05:45 PM
Dmanosaka Dmanosaka is offline
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As mine is a daily driver I'll have to pass on the sports cars of my dreams. Hope in the future I can find an older model with a manual for a weekend car. Luckily for us in the cities public transportation is amazing and everywhere. I'll jump on the train when driving becomes a burden. In the meantime I'll play around with this unusual auto shifter. Thanks for sharing.
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  #13  
Old 12-09-2016, 07:06 AM
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need4speed need4speed is offline
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It more fun to use the paddles, not as much as a true MT, but better than a regular AT
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  #14  
Old 12-10-2016, 06:23 PM
Dmanosaka Dmanosaka is offline
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I'll have to wait for a model upgrade. Looking forward to that. Thanks.
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  #15  
Old 12-11-2016, 09:23 PM
wspohn wspohn is offline
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While I agree that an automatic is faster in straight like acceleration, they can be rubbish for winding roads, if they decide to shift themselves when you happen to be right at the limit of adhesion in a corner (presumably on a road without other traffic, so what you are doing is carried out safely). If the transmission shifts under those conditions you can lose adhesion and possibly exit into the boonies, swearing at automatics.

The only autos that don't do that are the ones that will not shift until you bump the shifter.
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  #16  
Old 12-11-2016, 09:47 PM
Glaird Glaird is offline
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[. . . if they decide to shift themselves when you happen to be right at the limit of adhesion in a corner . If the transmission shifts under those conditions you can lose adhesion and possibly exit into the boonies, swearing at automatics.
The only autos that don't do that are the ones that will not shift until you bump the shifter.]

(On a race course, this will never happen, because after several laps, each corner will be mentally cataloged, for the optimum combination for our particular car.)

Yes, theoretically. In practice I'm not sure these two conditions line up that often; limit mid corner/accelerating into shift point. If you were using a manual transmission, or bump shift, you'd be at the red line. If you depress the clutch to shift up, off you go into the weeds. So what did we do in the old days? Enter the corner in a higher gear, having judged the turn/speed/shift point as we surveyed the corner ahead. Or, if caught by surprise, feathered the throttle and cornered as if in a momentum hp-limited car, until we started to loosen the steering wheel/radius of the corner enough to accelerate up to redline and shift.
Ergo, what would we do in a full automatic (Have had this happen to me on rare occasion.)? Feather the throttle, until we could open the radius of the corner. Similarly, with bump shift autos, feather the throttle until we can upshift.
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