Jorel C320

1) DO we have speed regulators?
IF SO...what speed is the limit?

2) When i downshift, sometimes the car jumps as if it were stalling....is that due to the esp?? And if it is...will it stop jumping if i turn it off?

3) Anyone feel any difference with turning it off? (turning it off as in just pressing the button..,not the whole menu ordeal)

THANKS

Flashman

According to the Road & Track full review, the U.S. version of the 2002 C230 Sports Coupe has an electronically limited top speed of 130 MPH.

It sounds like you are putting a ton of stress on the engine when downshifting. I don't advise using the engine/transmission as a form of "braking" when slowing down. That is what the brakes are for. Remember that in the end, it is a lot cheaper to replace brakes than it is to replace a transmission or engine. Baby the engine, abuse the brakes. Ideally, when downshifting, you should pre-rev the engine (when it neutral) a an RPM that is close to the specific RPM the lower gear will require.

shtatc

As I understand...the C320 are rev limited and has a top speed of 130. The C240 has a top speed of 140, but not sure what limits the top end.

Downshifting with the MB motors has been somewhat touchy for me. I am used to 'double clutching' and will rev the motor until it meets the right speed...but it takes time to know what revs corresponds to the right speed....the down side...early wear on the clutch assembly and transmission...so, using the brakes is the most effective way of slowing down.

Mike T.

Properly done, a double-clutch shift will put zero wear on a transmission, and even a badly done double clutch shift is better than letting the clutch disc and synchros drag the engine and secondary gearbox shaft up to the proper rpm during a downshift. The only thing that will wear more in a double-clutch scenario is the release bearing, pressure plate diaphragm springs and clutch linkage, due to the double action. These items are normally (by far) the most reliable parts of the clutch system.

I agree with Flashman about downshifting not being necessary for, say, approaching a stop sign or red light. But in spirited driving on a twisty road or track, double-clutch downshifts are absolutely necessary for smooth progress and to be in the right gear by the apex of some corners.

Double clutching will also ensure that your synchros (especially 2nd gear) are serviceable long after those of most normal higher-mileage cars have begun to fail.

Remember, simple rev-matching (throttle blipping) on a downshift only saves wear on the clutch disc, not the synchromesh units of the gearbox. A double-clutch action is necessary to prevent wear on these.

About clutch and brake longevity, my 1989 Peugeot 405 has been double-clutched (downshifts only) since new. After 160,000 miles, the clutch is in fine shape, not even the actuation cable or pedal rubber(!) have been changed. My brake pads last about 60,000 miles front and 120,000 miles rear BTW, and the front rotors lasted 130,000 miles.

The C 240 has a top speed in Europe of 146 MPH. The one tested by Car and Driver in January 2001 reached 143 MPH, despite the fact it was on HR tires (oops, way to go M-B) - it should have had a 130 MPH speed limiter.

revstriker

Just curious....

With all this talk about double clutching, I noticed that JoReL's original post says he has a 2001 C320. I know the 2002 models do not come with an option for the transmission (it's auto). Did the 2001 have this option?

Jorel C320

Sorry about the confusion. I meant to say was "downshifting with the sport shift", although i did learn alot by the "double shifting posts".

I knoe that shifting down with and automatic is bad at certain speeds that it cant handle, but i basiclaly wanted to know what mechanism controls the transmision. Any regular auto tranny will let the rpm redline and almost blow up the engine, but what stops the mb from doing that? HAs it anything to do wth the ESP function??

young

i have auto, and when i slow down, i used to downshift but it felt pointless. i was told not to downshift to 1 unless i was at a full stop. but generally, i was at 1 ~ <10mph, 2 ~ <20mph, etc.

now, i use the hold to left technique to downshift when i want to pass someone.

Jorel C320

YAH thats tru....the only time i downshift is when i need a sudden burst of speed. I dont up shift like a manual car would in normal driving. ...anyways.. one time i was going around 30 and i downshifted two gears down...which in regualr cars would be perfect for a burst of speed, but this time it jumped on me. SO i assume theres some kind of mechanism that holds it from redlining. am i right?? (it might be traction control????)

shtatc

I apologize for my ignorance...but when downshifting with the manumatic....can you simulate double clutching? I guess you can "match revs", but that may be as close as you can get. Maybe I did not read the previous post in depth to figure it out..sorry.

dasMafia

no.

i suspect that if the car is jumping, then it is because you are trying to put it in a gear that is too low for the engine. as a rule you should wait to downshift until you are preparing to accelerate. (as performed in an ML320)... use the brakes to slow down entering the curve, downshift tranny to 3rd to hold through (long, sweeping) corner. at exit, slap left and drop the hammer.