Just as we all see different fuel economy results because of our driving environment/styles, there is no "one size fits all" solution for oil changes. Kia's 3,750 mileage requirement is a worst case scenario and will keep you covered if there are any questions. If you feel comfortable exceeding that figure in your driving environment and are using appropriate synthetic oil and a good filter, then that's OK too, but it's your call/responsibility.so basically their is no consensus on the question of what mileage, what oil... guess I won't start another thread about it... I was told by the dealer to do 3500 miles
I live in Florida and drive mostly blend of city-highway. guess that works...
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.