How can be the fuel efficiency close when one of two uses premium gas. In cases like that better to use costs for gas per 100 kms instead liters per 100 kms. And something more - kudos to Mazda engineers to build this very high ratio engine still using regular!
It's close because the Mini beat the Mazda ever so slightly, even considering the extra cost of Premium. Remember, if this is important to you, Premium fuel usually has no ethanol in it; so there is some value to the extra few cents per litre. I'd also be surprised if, driven carefully, a 3 cylinder 1.5L turbo wouldn't surpass a 4 cylinder 2.0 L. Both, however, are exceptional.
The "head vs heart" is so appropriate in this comparison. For me - no contest - I want a Mini (must be the base and have that beautiful panoramic sunroof)! To compare cargo space, backseat room, etc. is a bit pointless, as the Mini is still mini. It now makes great use of it's dimensions and has, I believe, topped out in terms of size. That awful ride is also is thing of the past. BMW has performed genius for the current generation - all under $21,000 to start. I'm not on the fence on this one.