Can you use Dex III instead of Dex VI?

Using Dexron III instead of Dexron VI is not recommended, as Dexron VI is a more advanced formulation with improved properties, including better thermal stability and oxidation resistance. While Dexron III may be compatible with some older vehicles, using Dexron VI is advisable for newer models designed for this fluid. Always check your vehicle's owner manual for the manufacturer's specifications to ensure proper transmission performance and longevity.