Spirit Crusher

This has never happened to me on my W211 but I drive the car in E mode and sometimes, when the road is straight/no hills/etc., I'll give the car a little bit of gas and all of the sudden it will have a really obvious downshift. I can't figure out why this happens.

petee1997

I found my car would do a hard downshift sometimes on the small hill approaching my driveway. That lasted about a month and now it shifts as smooth as butter. I think it's all part of the break in period.
I don't know if it's all in my head but these cars seem to take three to six months before they really perform well.

hyperion667

I think you're right that it has something to do with the break in period....I was reading about that today on a manual I downloaded....

Spirit Crusher

Ah, I'm just hoping that won't put unusual wear and tear on the transmission!

E550Shopper

I've experienced similar issues on the '07E 4MATIC (5-speed) I bought with 50K miles on it. It tends to happen when I give it a lot of throttle, then either brake or ease up on the gas. There's tons of info online about this issue. Had it in to be looked at twice -- eventually was told it's normal. Best of luck.

LaicepsYdobon

Its normal don't worry. When you are driving in E mode the transmission looks to go into a higher gear to provide a more fuel friendly (Economical) ride. Our cars have 7 gears of which the 7th is pretty much an over drive gear. If driving under normal conditions the car will select 7th gear by 40mph to save you fuel. The downside of the overdrive gear is that it's ratio is set up so that there is not much torque found there since you don't need much torque for cruising. When you push down on the accelerator the car will leave the overdrive gear (7th) to look for a gear that has more torque so you can accelerate. Once you are done accelerating the car will go back to the over drive gear to continue your cruising. This should not wear out your transmission so no need to worry.