SLK55NEWB

I may get flamed on this but here are a few thoughts on the Auto transmission as I near the end of Break in Period.

Coming from a 5 speed manual on a Boxster, I really like the 7 Speed Auto. In fact, I highly doubt I can shift gears as fast as I need to and use the full effiency of the 5.5 Liter engine. This pertains to the 1st 3 gears.

I do not suggest manual shifting in S and C mode as the response can be slow depending on the acceleration. In M mode however, the manual shifting works to my satisfaction. It takes about half a second after pressing the buttons to switch into the next gear which if you think about it, may be faster than engaging a clutch, shifting gears and then disengaging the clutch. Downshifting multiple gears however seems to be a problem. This may sound like a newb question but does downshifiting an automatic transmission harm it in any way?

You really do feel the difference between S and C mode. S mode uses the higher RPM ranges.

I love this car to death. I thought I recieved a lot of looks when I first bought the Boxster but this car attracts quite a bit more. I am sure the aftermarket rims help.

Cheers!

Leef

Well, I'm not broken in yet (the car, that is), but I also like the auto. Contrary to some of the complaints I've read, it never has done anything wrong for me. Coming from a C32 I did have to learn the difference in what the controls do, but they work well. I use C in heavy traffic, S otherwise. I haven't played with M very much but will get a chance to on a back road trip this weekend.

I'm hopeful that life with this car will be great!

hellcat

The lag in downshifting is caused by the engine computer matching the revs for you. You can downshift faster with a manual transmission but it is a lot more challenging to get the revs to match perfectly to make it a smooth shift. This is what the MB tranny is doing for you. Frustrating when you want lightning fast shifts, but very nice any other time.

TEAShea

Good to hear.

TEAShea

SLK55AMG

Is that really what its doing?...... unless my memory is way off I don't remember there being any sign of rev matching going on during a downshift...... there is no blip of the revs before the lower gear slots into place (either audible or visible)..... with a manual downshift the 7G seems to just drop a cog and let the engine catch up accompanied by engine braking.

I found the car I tested unable to manual downshift smoothly under heavy braking so just let it change down itself (that is much smoother).

Some of the recent reviews of the SLK55 have also pointed out that the car gets unsettled during a manual downshift a sure sign that the auto is not rev matching before the lower gear engages...... or at least a sign that it doesn't rev match very well?

Perhaps the car I borrowed had a faulty gearbox?

blkslk55

slk55amg, i have posted somewhere before that i too have not experienced any difficulty and/or an annoying lag time whilst shifting with the paddles. i drive my '55 in the manual mode the car seems to be responding favourably with the gear changes.i am learning to drive the car for optimum changes without any hesitation changing gears.
i think that it is quiet simple, in that, like any car which you are diving, you will get to know the cars' tenedencies and the car will get to know how you drive it.
if you test drove your car for a short duration, then, you don't have a true feel for this car.
it is interesting, the more and the harder my car is being driven, the more the engine starts to roar and wants to be driven more aggressively! it is truly amazing what this car can do.
on the downshifting side, it is interesting. what i have noticed is that the engine will go into whatever the corresponding gear is given where i start to slow down or break. if i am downshifting i have not noticed any misses in shifting. i had to get used to this as i stated before, the more i am driving the car the more i am learning the tendencies is different situations.
in summation, i am absolutely loving the car more and more with every passing kilometer!


by the way if you have a boxter s on order why do you still have your name "slk55amg"?

cheers!

SLK55AMG

I had no real problems with the upshifts...... its just the downshifts that I didn't like...... as I said there was no sign of a rev match performed by the car during a downshift as suggested by hellcat...... the engine just races to catch up with the increased revs once the lower gear engages this is not a rev match in my book!

I tested the SLK55 over 4 days and several hundred miles of very hard driving (95% using manual mode), my only issues with it were the slow changes and bad downchanges under heavy braking.

Just because I have a Boxster S on order doesn't mean I'm not interested in the SLK55 any more so why would I change my user name?

blkslk55

it's interesting that you found the downchanges to be not to your liking, 'cause when i downshift under heavy breaking, the car will go to the appropriate gear as relative to the breaking speed i am in. so, i have not experienced and "bad" downshifting to date.

SLK55AMG

I'm not sure I understand what you mean...... when you say "when I downshift under heavy braking" that suggests that you are manually changing down to a gear of your choice...... yet you then say "the car will go to the appropriate gear relative to the braking speed" which suggests that the car chooses the gear rather than you? Have I misunderstood what you are saying?...... if not thats exactly the sort of poor gear change I'm talking about..... if I want a particular gear in manual mode the last thing I want is for the car to choose something different

When you change down manually when braking hard do you not find that the engine braking throws you forward as the lower gear engages? Thats what happened in the car I had so much so that it was much smoother not to change down at all if you were coming to a complete stop.

hellcat

It's possible the 7 speed in the SLK55 shifts differently as I haven't ridden in that car. I was speaking from experience with the gearbox in the E55. I know the SLK has a newer transmission than the E55 so it might operate differently.

blkslk55

"that suggests that you are manually changing down to a gear of your choice which suggests that the car chooses the gear rather than you? "...... would'nt you do this if you had a clutch? or would'nt you downshift into any gear with your clutch whilt breaking?
"which suggests that the car chooses the gear rather than you?".....wich is also the same as my comment above.

anyone else care to chim in with your experiences?

SLK55AMG

Sorry mate you have totally lost me now...... I don't understand anything in your last post...... you have edited my original post such that it doesn't make any sense (not even to me) and then quote something that I didn't even say "that suggests that you are manually changing down to a gear of your choice which suggests that the car chooses the gear rather than you? " you've joined several of my comments into one quote that doesn't mean anything to me.......

Please clarify one thing for me...... do you manually change down or do you let the car do it for you?

SLK55AMG

EDIT: having read your last post a few more times to try and understand it...... are you asking me if I change down while braking?

If so the answer is yes of course! My point is that the 7G auto doesn't change down smoothly in manual mode under heavy braking....... I can get a much smoother down change in a manual car by heel toe shifting.

blkslk55

i have taken a bit of time before writing another post to your quote above. i have driven my car ('55) in many different circumstances whilst i will agree with you after reading what you had to say but, i think that i am so familiar (sp?) with driving my car that i had to go out of my to have the car change down throught the gears in a rough manner.
i am so used to dirving the car now in the manual mode that i find it quiet easy to downshift at whatever pace i want to (even though the car will automatically double shift down to a lower gear depending on how hard i am driving it).
to tell you the truth, i think that i am completely comfortable with my car and how it drives that the little nuances which some purists may not like, are a non issue to me and the car still drives like a bat out of hell!!