Non-expert opinion warning!

Manually shifting the auto 240D is a necessity in traffic. My view is that the MB engineers gave you the option of shifting manually, so use it all you want without damage, in a proper transmission.

There are little dots on your speedometer to show you the shift points. I suppose those are the maximum and that’s the way I use them on the 240D. When I "accelerate" with full throttle, the dots are where the transmission shifts on it's own when in auto mode.

Enjoy!

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2002 E320 Sedan 93K Designo Mocha Black Metallic!
1995 E320 Wagon 205K Black Wagon
1982 240D 183K SloPoke

I believe each of these cars are the final production year for that model.