tifosiv122

So I went in for Service A today and they gave me an '03 240 with 3,000 miles on the car...basic car with auto..no other options that I can see.

Anyway, since I have a stick I decided to try their auto-stick thing. I put it into 1st and drive...the car auto shifted to second around red-line. Do all auto's do this? If so, whats the point if you can't hold the car at a certain gear? The car kept switching gears when I didn't want it to. I got so tired of 'fighting' the car I just put it in 'D'.

Thanks,
Erik

2SYKbenz's

At red line the automatic will automatically up-shift to prevent damage to the engine. An MB automatic transmission I think is one of the smoothest and best out there. If you were driving and then held the shift knob to the left for a few seconds, the car would down-shift into the lowest possible gear for the speed you are going (for more sport driving). Other than doing that I think that it is slow to up shift when using it in touch mode. One of my cars is the 6 spd and the other is the auto. I love driving stick, but next to that I think the MB auto is the best, but forget driving it in touch shift mode

tifosiv122

I understand it stoping the fuel at rev-limit, but i don't understand it shifting...maybe its just me, but then I really don't see the point.

I agree it is very smooth.

Erik

tberry

The MB auto is the one of the lightest, aggressive yet smooth auto tranny around. it does shift at redline (actually sometime about 200rpm into redline) but so does every other auto/manumatics (i.e tiptronic). The only other true alternative to tradition manual is SMG (i.e clutchless manual). The upshifts are kinda useless but the downshifts are pretty nice (like when u wanna "hold" a gear in turn).

2SYKbenz's

my best guess without going and looking is that in an automatic when you near or hit red line, it automatically up shifts. In the manual when you hit red line to prevent engine damage since it can not upshift, it just cuts the fuel. Both ways it is simply trying to preotect the engine, because after red line you're engine is not getting enough fuel into the system and damage can be done.

MarkL

Agree 100% -- the upshifts follow the "normal" shift points for the selected gear. I have a 6-spd in my C240, but we have a manumatic in our Acura 3.2TL. That trans throws me sometimes even when it's in full auto because it's the first auto I've driven where it holds a gear as you're coasting at lower speeds. You can feel the kickback when you let off the throttle...

tberry

I do have one question about the delay of the touchshift upshifts. I rem in my A4 tiptronic I can guess the delay of shift to about 300rpm (+ or - 50rpm), meaning that if i wanted to shift at 5300rpm i would do it at 5000rpm resulting in about 5300rpm shifts. After looking at the dyno charts of my pullied car ideally i would want to shift at about 5700rpm however if i leave in full automatic it shift at either 6000rpm or sometime even 6200rpm. Does anyone know whats the delay/discrepency of the touchshift tranny so that I can get more precise 5700rpm when u're pushing full-throttle? Thanks.

bajaiman

My C200K auto box WILL NOT upshift automatically by itself if I manually tap the gear lever to 1, the car was over revved a few times (about 500rpms or so). I think it only applies to the car which has “tippshift” feature. In Australia C200K sedans don’t have it.
Good thing is that I can treat it like manual where I can revved it all the way to redline without upshifting, bad thing is over revved like my friend did to my car as hes not accustomed to the car
I normally manually upshift about 5500rpms resulting in about 6000rpm upshift if I drive aggressively.

tifosiv122

Thats what I'm talking about...why doesn't MB offer that in the US?

Erik

noodlesoup

i have an auto, but when i put the gear in 3rd gear, and car stopped. it will still go from 1st gear and slowly shift to 2nd. and to 3rd...why is it like that?

and for the auto mode, i think my 240 is slow in auto shift. something it will wait til 4-5k rev to shift..is it normal to all the 240..i know 320 won't do that...??

peet

Maybe it's smooth - but it just doesn't work very well with our wheezy engines. Driving around in D the transmission wants to go to 3rd or even 4th gear while going 30-35 mph!? When I had to pass someone, even when clicking the button (under accelerator) it still took a good 2-3 seconds before the car's systems agreed and shifted down.

This was unnaceptable. In an emergency situation you have to be out of the way then and there.

How did I fix this transmission problem? Simple, traded it in for a stick! I can't believe what a difference the stick makes. Hold your gears as long as you want, keep it there. Life is good again.

Peet

FrankW

why would you want the engine to cut off the gas when it can upshift? Give me an example when you have to keep it in the redline all the time.

if the engine redlines and shifts, it means that you have enough distance to upshift and go faster. just downshift when you reach the end of the straight.

for noodlesoup, because it's an AUTO. BMW's SMG II will also put you in first when you stop. I think all the new MB has transmission that will learn from your daily driving style. You can upshift by tapping right if you want to shift early.

bajaiman

2 to 3 seconds lag is definitely too long for the car to automatically downshift, my car will downshift about 1 second after I pressed my foot down. I think the car adapts on your driving style, if you normally drive really easy/relax then the car may take longer lag to downshift compared to other people who drive the car a little bit harder.