Personally, after break-in at 5K miles, I'm now running Mobil1 0W-20 and either a Kia OEM filter or the Mobil1 Extended Performance filter. But, my typical driving is cake for the car. It's usually cruising at 50-55 mph on a long two lane commute, virtually no city driving, and little high speed interstate driving. I also don't live in a particularly hot or dusty environment, don't tow anything, etc. In my conditions, and using top tier synthetic oil, 7,500 is easy mileage on an oil change. However, this interval would not work for some owners.
I've also used Blackstone testing on my smart fortwo in the same driving environment using Mobil1 oil. 10,000 miles is obtainable (and recommended by the manufacturer) with life left in the oil (confirmed with actual testing), but I still change it around 7,500 to be on the conservative side. A previous Honda Civic with its own oil maintenance minder always went to 7,500 in my conditions as well. As always, YMMV.