A response based on researching fluids for a friend's 2006 Kia Sedona:
As with the matching Hyundai vehicles, Kia vehicles of a few years ago seem to use rather generic fluids. While there are no guarantees, SPIII may be no more than Dexron III. When the transmission in the Sedona noted above began slipping during upshifts at the 110,000 mile mark (dealer serviced until then, with of course no transmission fluid changes since new), I immediately swapped in MaxLife. Within a few miles of driving the slipping was gone. 40,000 miles later the transmission is still okay. Would new SPIII fluid have done the same? Perhaps; there's no way to know. I used the MaxLife because I like the way it works in the notoriously weak transmission of my 2001 Honda Odyssey (another transmission where until recently 99.9% of forum posters predicted transmission mayhem if anything but genuine Honda fluid was used). It's difficult to not have suspicions that some of the "weak/fragile transmission" issues don't have a link to unsatisfactory OEM transmission fluids.
The power steering fluid reservoir in the Sedona has since the transmission episode been periodically drained and refilled using Dexron III. Still works great, hot or cold (cold here being well below zero at times). The cooling system has been treated to occasional drains and refills of the generic green stuff, as specified in the manual.
As a side note, I made a slight misstatement when I made the comment above about dealer servicing. I've been changing the engine oil and filter since about the 40,000 mile mark. Time pressures wouldn't allow an appointment with the dealer, so I pulled the drain plug and filter. The oil didn't look bad, but the filter was black and crusty. There was no conclusion possible other than the dealer's technician's had not been changing the filter (an easily accessible cartridge type), though of course the work record billed for the filter each time. Since that time, I've changed the oil at 5,000 mile intervals and the filter every 10,000. The filter has looked nearly new at each change.
As a side-side note, the transmission in my 1994 Chrysler minivan still shifts like new in spite of having a failure-prone reputation. Perhaps it's still going strong because early in its life the much improved ATF+4 fluid was swapped in. Just another anecdotal reference to the possible benefits of good fluids.
