SP-III Automatic Transmission Fluid

Unless you drive under severe conditions, the interval to replace fluid on
the Sonata is 105,000 miles.  IMO, waste of time and money to do it sooner.
Is the Santa Fe different?

No, it is the same, but I've seen people post about how bad the fluid
looks at 30-40,000 mile range already.

Besides, it's smart to change it more often than what the manufacturer
'recommends'.  They would rather sell you a new car than see you still
driving the same car for 10-12 years.  In other words, their intervals
are not designed to give your vehicle the best chance to last well in
excess of 100,000 miles.

I only ever changed tranny fluid in one car.  That is the only car I've ever
had a tranny repair on.   I'll take my chances, even for 150,000 miles.

A couple of things:

*If you do change your fluid, do not use anything other than SP-III, unless
it is the new SP-IV, but from either Mistubishi, Kia or Hyundai.  The
compatible stuff would not seem to be, at least it wasn't in my tranny.

*If the interval is 105,000, don't worry how the fluid looks. If SP-III has
one flaw, it is that they don't put much in the fluid to keep it looking
like ATF (it isn't all that red when its new).  But even though it looks
bad, it should still function okay.