W210 Auto box ratio

[MP210]

I was driving on the motorway today doing 70 mph and I noticed the rev counter was around 3,000 rpm in 5th. Is this right?
I shifted down to 4th and the rev went to 3,500 rpm at the same speed?
Should there be a larger difference in revs between 4th and 5th?
Does anybody know if this normal?

Cheers

MP210

 

[shandy]

Read your handbook, all this information is there.

 

[Dieselman]

Depending on the engine size it sounds about right. 23.3mph/1000rpm.

 

[Tigger]

Definately depends on the engine size / type.

My W210 E320 CDI will do 100mph at 3000rpm on private roads. On public UK roads it does no more than 70mph.

 

[tamrsoft]

I have an E220 CDi auto (2001 model) and in 5th it is doing 70mph at 2300rpm and at 60mph it is doing 2000rpm. Does any other member have comparative figures. I note previous members comment about checking handbook, but mine does not give such information, does anyone know where this can be formally obtained from. It would be useful to be able to assess whether there is slippage in the tranny.

 

[MP210]

Thanks all,

I'll have a look in the manual.
My car is a E200k auto (2000 model)

 

[Dieselman]

I have an E220 CDi auto (2001 model) and in 5th it is doing 70mph at 2300rpm and at 60mph it is doing 2000rpm. Does any other member have comparative figures. I note previous members comment about checking handbook, but mine does not give such information, does anyone know where this can be formally obtained from. It would be useful to be able to assess whether there is slippage in the tranny.

Slippage would be obvious on hills and the electronics monitor this anyway.
30mph/1000 is correct for your car.

 

[Dieselman]

My W210 E320 CDI will do 100mph at 3000rpm on private roads. On public UK roads it does no more than 70mph.

What still at 3000rpm? It must have variable gear ratios...

 

[Dieselman]

I don't know why MB do it but their cars are always undergeared.

I realise it's to increase acceleration but the top ratio really should be either an overdrive or at least ideal sports.

A quick check of the best ratio is to see if the top speed is attaned above, at or below peak power output.
If below then it's an overdrive ratio, if it's at peak power then it's ideal sports ratio, if above peak power then the ratio is too short.

 

[tamrsoft]

Dieselman

While we are on the same topic - do you know how the tranny ECU controls the TCC. Is it locked up above a certain speed (or rpm) in a specific gear or is it continually locked/unlocked during normal variable speed driving (acting like an additional gear ratio).

 

[Dieselman]

The converter clutch gradually locks as a result of the vehicle speed and the load on the engine.
The faster you go with a lighter throttle the more the clutch locks and vice versa.

This is performed by hydraulic pressure from the gearbox via a solenoid valve.

 

[se97mlm]

This link explains the lock-up clutch wuite nicely

http://mb.braingears.com/W210/w210/trans2_torque.htm

 

[tamrsoft]

Great article, I have been looking for this level of description for the 722.6 tranny for some time.
I did not realise that the TCC spent a lot of it's time in slippage mode over a wide range of engine rpms, I always thought it was either locked or unlocked. It probably accounts for why when approaching final cruising speed I see the revs slowly dropping before finally settling down to a steady rpm value at final constant cruising speed.

 

[colin.dillon]

Rev/ratio

Tried my '98 E300TD estate this morning - @ 3000 rpm doing just 95. When take it out of overdrive revs increase by about 500.

Sounds as if somethings amiis!

Col

 

[Dieselman]

Tried my '98 E300TD estate this morning - @ 3000 rpm doing just 95. When take it out of overdrive revs increase by about 500.

Sounds as if somethings amiis!

Col

Why does it.
These cars are about 30mph/1000revs.

 

[colin.dillon]

Why does it.
These cars are about 30mph/1000revs.

Didn't say what I meant!! MP210 may have a problem as his is doing 70 @ 3k.

Col

 

[Dieselman]

Didn't say what I meant!! MP210 may have a problem as his is doing 70 @ 3k.

Col

No, it's a 200 pertol. They only run a short ratio due to lack of torque.

 

[se97mlm]

But it's a 200k, so if it's anything like a C-class, 3000rpm should be about 85mph. There was a website i came across once that had all the gear and axle ratios for mercedes. I'll have to see if i can dig it out...