I have a 2014 Kia Rio with a 6 speed auto. It asks for SP-IV specification transmission fluid.

The transmission shop I am considering for a fluid change service, said that they use an all purpose Dexon6 fluid. They said they then add in a special friction modifier, which will then augment that fluid to meet different manufacturer specs.

So they take the base fluid and add in the ford spec friction modifier for a for trans, and add in a kia spec friction modifier for a kia.

Is this normal in the automotive service industry. Is this acceptable? Is this approved practice by OEMS?

  • I wouldn't do it! It's their word against the manufacturer's recommendation for SP-IV. The correct fluid should be used or you run the risk of damaging the transmission (at worst) or having it perform poorly.
    – jwh20
    Commented Nov 14, 2019 at 19:23
  • These modifiers have been used for years with success, this all started when manufacturers started to have their fluid custom blended from base stock Dexron fluid, these modifiers do the same thing as the modifiers manufacturers use in their fluids. I have used these in trans flushes are overhauls since they showed up in the market, no problems ever.
    – Moab
    Commented Nov 15, 2019 at 15:44

2 Answers 2


I'd have concerns about invalidating your 10 year powertrain warranty on that car. Maybe get a quote from the dealer for the same service; if they do something similar, you know it'll be OK.

  • I am in Canada where Kia's powertrain warranty is only 5 years. So I am off warranty. The shop is charging $179, and is a highly reputable transmission shop. The Kia dealership is charging $279, and they are (in my experience) a bunch of clowns.
    – Scorb
    Commented Nov 14, 2019 at 17:58

Not a single car maker approves of using a generic fluid and a friction modifier. If you're going to get a fluid flush or replacement, demand they use the factory recommended fluid or don't do it at all.

  • Why would they approve it, they want to sell their high priced fluid.
    – Moab
    Commented Nov 15, 2019 at 15:45
  • What you don't understand is that no single universal fluid can possibly meet the specs of all car makers. Some of the specs are actually mutually exclusive.
    – user9181
    Commented Nov 16, 2019 at 0:17
  • I understand perfectly.
    – Moab
    Commented Nov 16, 2019 at 1:01

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