Difference between C and E modes?
 

I'm curious why it is that when I start the engine on the 2019 S450, it always has the C (Comfort) driving mode even though I change it to E (Economy driving mode). This is obviously not a big deal, but I like to have it on E for fuel savings since I want the car to go as many miles as possible between refills (not for saving money). Is there any difference on fuel savings between the C and the E modes? As far as comfort is concerned, I don't notice any difference at all in the two modes.

In E Mode the car should optimize the fuel efficiency as much as it can such as lowering A/C Fan Speed, softening the gas throttle inputs , changing the gears at lower RPMs and switching to sail mode or coasting by just switching in N even when the tranny is in D .Oppps How could I forget ? Turning on the ASS (Auto Start Stop ) However, in Comfort none of things should happen aside from turning off the ASS

Thanks a lot for that info. I have one more question: Why does it always default to C mode when I start the car even though I had left it in E mode?

Because Mercedes knows what you want more than you do.. It irritates me too. I can't even have the volume on the radio where I want it in my wife's car. If I turn the volume all the way down to 0 when I get back in it's on some minimum setting that I can still hear. At least the display in the instrument cluster stays put now. in my w221 it defaulted to the same thing every time.

Mute not volume=zero
Mute is retained over engine stop and start.
Volume = zero is reset because the volume control controls lots of volumes {radio, navigation, emergency,...} and at startup yu might no be able to cause the right circumstance to transpire so the volume control can control the volume of the desired device.

There is no difference in comfort between the C and the E modes, right?