DangermouseCLK

Does anyone actually use the One Touch Gearshifting feature – i.e. the (D-) and (D+) functions on the transmission for regular driving?

I mean obviously I know that one would shift into 2 or 3 for poor weather or slippy surfaces, but what does this +/- gain you over a traditional PRND321 or PRND21 unit

I tried moving through the gears with it one time, just out of curiosity, but it seemed weird, compared to a traditional stick shift.

Yidney

Most every auto car has that feature these days, and my sense is the same as yours - it get's used by most people about as often as that exercise bike in your basement. I think you need to get good at it to use it to much advantage. One place it can come in handy is to keep the revs up so you can tap into the power more quickly for a quick pass or acceleration at lower speeds. One thing that bugs me about my 550 is the flat spot/lag if I punch it while cruising at at say 30-40 mph. I have had little turbos with way less of a flat spot.

Klinh

It actually confusing if you don't use it all the time. The buttons or paddle on the steering wheel is much better knowing which is Up/Down.

Rudeney

I don't use it often on the CLK550, but I did quite a bit on my other cars - ML320, BMW X3 and C240. Mainly, it helped give me better performance on those V6's. The 5.5 V8 really has enough power in normal driving that I don't need it. And my adaptive transmission usually stays in "drive-it-like-you-stole-it" mode. I have found that on the 722.9, a simultaneous accelerator stomp + left-tap on the TouchShift = Absolute maximum torque downshift = "passing with authority".

On the other side of that, sometimes while cruising at 40-50mph, I see the RPM's close to 2K, so I tap right to force an upshift and save a few teaspoons of fuel on the daily commute.

Yidney

Rodney, do you know what I mean about the flat spot I described above? Does your 550 do that too?

Kevwood

I do all the time to keep me in practice, it just becomes automatic to always be in the optimum torque curve. Funny that when I don't, the car feels sluggish and unresponsive.

kbahl21

in normal driving mode that happens to me too, if anything downshift then romp it. Oddly enough, if im driving in dynomode that "flat spot" isnt there anymore

elijah

I use it all the time but mostly to downshift. I tend to use the brake pedal much less while using the paddles or shifter.

grech

Persoanlly never used them on the CLK or E, never liked that they're more for putting an upper limit on the gear number rather than actually use them to stay specifically in the gear you want to be, also their sluggishness never helps either.

togaclk55

If you were to downshift in M mode and romp it to redline does it shift for you or do ya gotta upshift yourself?

Glyn M Ruck

Used it a lot more with my 5 speed Mercs than with the 7G.

Frank Rizzo

I use it all the time. It's easy to reach down and slap it left and right. Jus' like my Ho's

Mka77

The perfect instruction manual!

Moedy

In M mode it wont shift at redline for you

AMG_BENZ

I may be wrong, but that's where I heard. It will last longer your transmission if you do the one touch gearshifting than leave your transmission automatic. Is that true?

Rudeney

Yep, mine actually makes kind of a rumbling noise/feeling, but I had the TCU reflashed with the latest software yesterday, and I haven't had time to see if that helped yet. They did this after the timing gear work when I complained of some transmission slippage/slamming. I think they had to disconnect a transmission fluid cooling line during the job and it lost some fluid. I took it in Monday and they had to add some fluid, and did the reflash just as a matter of course during the service. The slipping/slamming is gone, but with the rain, and just one trip to work and back, I haven't had time to "play" to see what the real differences are. Mainly it seems to hold RPM's higher during shifts, which makes things much smoother.

lowpost

hah hah..true playah for real

lowpost

I mostly use it when in stop and go traffic - knock it down to 2nd or 3rd.

ahmadk

I used to use it while messing around with my friends on the highway

ellcapitan

I think its just a gimmick. It doesnt really do anything the old style Lo-1, Lo-2...etc...used to do. Since its really just software, its easy (cheap) to manufacture, and likely contributes to more auto-trans. sales, which means less manual sales, where applicable (again, saving the manufacturers $$).

Kevwood

I have to disagree with you, I think it's an excellent added feature. I could easily prove that by doing 3 laps around the Autodrome or YAS with the car left in drive and then 3 laps using the shift padels - there would be a considerable difference in average lap time, trust me on this one.

ellcapitan

I would agree if we were talking about an automated manual ("manu-matic") or a DSG, but I'm having trouble wrapping my mind around the idea of anyone being able to manipulate a traditional automatic better than it can manipulate itself.

Kevwood

Very simple, imagine this, your diving into a corner and brake hard, coming through the apex you floor it, the car revs up, catches the gear, spins the inside tire, traction control kicks in and you eventually go on your way...

Or,

Speeding into a corner, downshifting as you brake keeping the revs in the 3500 range, through the apex you feather the accelerator through full throttle and leave the newb that drives his car on the track in automatic way behind...

Like I said, trust me on this one, I've got a bit of seat time in a few different cars with a few different trans setups. By no means is the trans touch shift a sports trans setup but then again, these aren't sport cars from the factory - they are touring cars.

Touch shift gives the driver some additional control, that's pretty important when your running time attack trials.

Rudeney

One thing to note is that there are differences in the operation of the TouchShift based on software versions and transmissions. The TouchShift up to MY2001 simply shifted up and down one gear at a time, just like running the old-style "zig-zag" shifter through it's gears. Also, it would hold the gear and do a fuel-cutoff at redline. In MY2002, they changed the software so that it would auto-upshift at redline.

The 722.9 transmission is different. First of all, it mechanically can shift across gears. I believe it can actually skip up to two gears in a single shift, i.e. it can go from 6th to 3rd without having to go through 5th and 4th. Because of this, and the number of gears, the TouchShift is programmed to select the "optimal gear" when first downshifting from "D". If you are coasting, it will go to a lower gear to gently assist with engine braking. If you are accelerating, it might downshift one gear below whatever physical gear it's in, or if aggressively driving, it will shift to the lowest possible gear given the road speed.

While the mechanical process of changing gears is no faster or slower with the TouchShift, using it can result in apparently faster shifts since the driver's gear decision might be faster than the vehicle's electronics.

I will say that I used the TouchShift more in my V6 engines as I felt like I got better performance with me making the decisions. On the CLK550's V8, I rarely use it as the engine has plenty of performance just letting the car make the decisions.

Kevwood

Good point Rod, something that I totally forgot to mention - while braking if you hold the down shift for someone like a second it will but the car in the optimum torque gear (3500ish rpm). Very handy feature indeed.