Will using the steptronic in the MCa give better millage?

 

Sure.

With it, you can upshift earlier than the AT would choose to do so, and, you can hold in a higher gear than the AT might choose to use in any particular situation.

However, the AT will automatically downshift to prevent RPM from dropping too low, as it will auto upshift to prevent exceeding redline.

In my case, with careful use and a soft, steady right foot, I can get above 40 mpg on surface streets, which is significantly better than I would do in "D". The impact is much lower on the highway, where the AT will lock up with torque converter in 6th whether in "D" or "M6". At least, I assume these trannies use torque converters.

R56 MC

 

I should qualify that. Unless I have the tach display set to show mpg at one second intervals, and am trying to improve my efficiency (not exactly hypermiling, just trying to watch consumption performance) .... I drive "spirited." I drive with "sport" button engaged, and use steptronic primarily for personal control of RPM. My typical average mileage is in the mid '30s, with the bulk of that highway.

And it's an MC, which gets a bit better mileage than an MCS. I only miss not having an MCS between 30 and 80.

 

From a basic stanpoint steptronic gives you more control over your RPMs so you would think so. But better milage is also dependent on other things, like smarter braking, using cruise control, etc. Check out the thread/link on hypermiling, while you don't need to go to extremes there are some great gas saving tips in there.

 

I normally lose mpg in that mode, prob because i love the sounds of high rpms.