I've put premium in the MINI since the day I bought it since the manual says to do so. So yesterday was the first day that I put a tank of regular in it.

Why?

The engine has been sluggish at startup after sitting overnight. It sputters and “harleys” for a bit before purring normally. Trying to find a cause and solution to this problem leads you to the forum holy war between MINI know-it-alls. Some has suggested to put a tank of regular in to fix that problem. Some say it has to do with the ethanol that's being added to gas in the summer. Whatever it is, we'll see if this makes a diff.

Link to an MP4 movie of the MINI sputtering in the morning. (:10, 400KB) You may want to turn up your speakers or use headphones, it's a little hard to hear. Use the tachometer as a guide to what you are hearing, you'll see the needle swing up as the engine settles.

Image by cobalt123 via Flickr, under Creative Commons License.