Sequentronic

[niva441]

I thinking of changing my W202 C250 auto for a W203 Sport Coupe CDi. In addition to the conventional auto it's also offered with the sequentronic, which appears to be more efficient.

Does anyone have any experience of this?

I'm thinking in terms of driveability, pulling away, manoeuvering, hill starts etc. Having driven other cars with simialr transmissions I've found they appear to suffer hunting / clutch silp when manoeuvering. Hill starts weren't a problem, but other cars have conventional handbrakes, not the Mercedes foot operated parking brake, that can't be modulated.

Also what's it like long term, are it's economy benefits likely to be offset by a large bill for repairs at some point. Not that I'm paranoid but I have limited confidence in electronic controllers.

Look forward to hearing from you.

Todd

 

[pascal]

There has been some problems with that gearbox, but maybe not enough to suggest that there is a quality issue. Most people I know leave it in auto for the majority of their driving. I don't think you would get better economy either, as it will down shift itself anyway if you reach the limit of load for that gear, just like gentle driving in 'C' on a standard auto.

Why not buy a 5sp auto. You don't need to use your footbrake on an auto in a driving situation, even going up hill. Car is left in 'D' and right foot is moved from brake to the throttle and back again in a start stop situation. 'N' never needs to be selected whilst driving.

Pascal

 

[niva441]

My expectation of better economy comes from the elimination of torque converter slippage, and is also suggested by the specifications. Although it would be interesting to see if this is realised in real life.

With my current auto I have needed to use the parking brake to do a hill start (fortunately only the once), so I'm interested how the sequentronic would perform.

 

[pascal]

I am not sure at what speed the torque convertor locks up at, but would imagine that the difference would be minimal.

Regards the hill starts, i do believe that some diesels need a bit of revs to hold on inclines with brake off. There is always the left foot on the brake option though.
The newer Es have a comfort device, that actually locks the brakes when when the pedal is depressed fully. It is then released when you accelerate.

 

[piestore]

sequtronic

Hi

don't even think about it get an auto. If you insist on going down this route make sure you drive one. In manual its great fun for 10 minutes but when play time is over the auto mode is apauling


don't do it

 

[niva441]

Thanks, I'm interested to get some real world feedback on the automated manual. From the specifications it's tempting, but if it jerks with every gearchange then it would soon become very tiresome.

I drove a automated manual Transit a couple of years ago and behaved pretty well, apart from manouvering when the engine revved a lot, implying clutch slip.

More recently the Mercedes specialist gave me a Corsa Easytronic (well it was an Elegance). Even though it was a Corsa I was still quite impressed.

I've already tried an W203 auto a couple of years ago. The only problems with it were that it tried to pull away in 2nd and the lack of engine braking driving down lanes, both things the same as my W202. I need to find the time to try it for myself.

 

[psmart]

This thread is a little old, but for those still pursuing the question... sequentronic.

We've owned a C220cdi saloon from new with sequentronic, and I give it the big thumbs up! You buy and use according to your requirements. I have an Auto ML270 and the sequentronic is not as smooth, but the 60+mpg average I get being ferried to Manchester Airport is only a dream in the eyes of auto-box owners, and lower tax rating.

If your a boy racer (I used to be... see earlier posts), then stay clear of the sequentronic, otherwise, adjust your right foot and its as smooth as a babies but!!! ie. When accelerating, 1st-2nd gear is a little rough (ie. like your left hand changing gear (i think most auto-owners have forgotten how rough their left hand was)), but if you blip the accelerator quickly, then its real smooth.

Hill starts - the sequentronic acts like an auto, ie. it has creep mode, which works, depending upon the hill gradient. Otherwise, just use the left foot to press the brake, press the accelerator, then release the brake, control is in the right foot as to wether you hold, roll backwards or go forward. I used to eat clutches in every manual I've owned, no such issue with the sequentronic!

In all honesty, you cant beat auto-boxes for lazi-smoothness, but then you pay for lack of performance, top speed and the mighty 'blair in the but' fuel costs/road tax!!

 

[niva441]

I don't think MB offer this system anymore. It's a pity they didn't persevere with it and smooth out the glitches as it does seem the potentially offer the best of both worlds.

 

[angus falconer]

I don't think MB offer this system anymore. It's a pity they didn't persevere with it and smooth out the glitches as it does seem the potentially offer the best of both worlds.

I don't know who supplied the Merc boxes but the Alfa Romeo version was big trouble. Early versions of Aston and Maserati took a lot of flak from the press.

IMHO the best solution is the DSG box offered by Audi - seems to be the best of both worlds.

 

[psmart]

I havent looked in great depth, but on the C220cdi, it seems to be the same 6 speed Merc box as used in the Manual cars, theyve just added an automated clutch and control systems. The only trouble we've had is the BAS/ESP light coming on, reporting a failure, which was resolved with a new wiring loom (it was one of the first RHD Saloons to have the seq box).

 

[niva441]

IMHO the best solution is the DSG box offered by Audi - seems to be the best of both worlds.

I wonder what the difference is between DSG and the PDK system (Porsche Doppel Klutch), Porsche were working on in the 80's. Sensors and actuators will have improved, but the concepts seem remarkably similar to me.

 

[zishan03]

I have a C200 Coupe with the sequentronic and I love it, but it is not without its faults. Everytime the car changes gear whether in auto or manual, there is a thud from somewhere in the car, I had this looked at by mercedes, they changed the diff and the gearbox only to get a similar car in at the same time which had the same problem, so deemed it a charachteristic of the car (I would love to know if other owners have the same problem). Secondly, the changes in auto mode are nowhere near as smooth as a convetional auto but some times when you are in the gear changing zone, you can make the car shift like a dream, its just a combination of changing at the correct revs and placement of your right foot on the accelerator. Occasionally in auto mode the time it takes to downshift can get a bit annoying but is not a major issue, and sometimes the gearbox itself mis-times a down change and you get a big whack up the backside (again, it would be interesting to see if other owners of this gearbox have the same problem).

Hope this helps a bit, if you have any questions, feel free to ask.

Zishan

 

[psmart]

On the C220cdi, the thud you describe can be made to occur, but only if you flat-out accelerate, and it occurs mainly on the change from 1st to 2nd gear, because it seems to hold onto 1st for too long and then dumps the clutch. On standard acceleration, the change from 1st to 2nd can be a little rough unless you blip the accelerator, then its smooth. Manual changes of gear seem problem free, but I suspect Ive adapted to its characteristics and I change gear/control accelerator in syncro. A quick test - take a Manual car out which has rear-diff, thrash it and dump the clutch - you'll get the same thud as the rear diff takes up the power. The software controlling the boxes could definitely use some fine tuning, and if Mercedes had not been discouraged from overpaid press who wont adapt to anything in their pampered lifes (ie. Clarkson/Hammond), then they would have probably smoothed the software out. Shame Mercedes wont make the software 'open-source' as I could definitely tweak it.

Other thoughts are that the C220cdi (diesel) isnt the same as the C200, probably down to the characteristics of how the Kompressor engine and the Diesel generate their power/torque and its application to clutch engagement.

The family and myself have adapted to the ways of the sequentronic and we have smooth cruising. Hence my earlier comment about boy racers - ie. if your hard accelerating all the time, max revs in each gear and your expecting the sequentronic to be as smooth as an Auto without manual intervention, then its rough. Add a little 'human' input (ie. accelerator control) to hard accelerating and it will be smooth.

In respect of kickdown, we dont have any problems, unless the Turbo is off song (ie. the engine is around 1500RPM when kickdown occurs), when it takes a second or two until the Turbo winds up.

Basically, to own a Sequentronic you must Learn. You learn the ways of a Manual when you learn to drive (most of us), You need to Learn how to use an Auto-box (but for most Manual drivers, its a doddle), so why not Learn how to use a Sequentronic? I think therein lies the problem, many people dont want to Learn and are thus quick to put the dagger in (Clarkson) - remember the tilting trains, which us British invented in the 60's, but our press killed off???

 

[MercTech]

Lockup Speed

The torque converter lockup feature will not engage until the vehicle reaches approximately 40 mph. If you really want to know more check out:

http://dnr.louisiana.gov/sec/execdiv/techasmt/ecep/auto/f/f.htm

 

[niva441]

Basically, to own a Sequentronic you must Learn. You learn the ways of a Manual when you learn to drive (most of us), You need to Learn how to use an Auto-box (but for most Manual drivers, its a doddle), so why not Learn how to use a Sequentronic? I think therein lies the problem, many people dont want to Learn and are thus quick to put the dagger in (Clarkson) - remember the tilting trains, which us British invented in the 60's, but our press killed off???

Don't get me started on Clarkson and the genre of motoring journalists that ape him. He present a very entertaining motoring related TV show, unfortunatlelymany people actually believe what he says.

 

[psmart]

100% with you, he (Clarkson) makes very good and interesting entertainment, but qualified to judge technology...erm!!! I gaulp!!! Sequentronic or its namesakes (from other manufacturers) should be the subject of a Professional review - ie. like this forum - real people, real experience, real feedback.

If I hadnt of had a glow plug issue with my ML, I wouldnt have even known this Forum existed, but after reviewing it, its 1000% better, professionally, than any sad comedy show (top gear!!!!).

I was considering upgrading my ML, but after all the true-to-life info from members, I'm happy to see my existing ML out for at least 3 more years. Keep it up guys n gals, this forum is a*******.