SE NC. Not near as bad as FL or TX but still sweltering sometimes Jul-Sep. My 9000 is not a turbo, though so I'm not too concerned with bay temps.
Then you should know -- the difference between Pentosin and DexIII is minimal -- except the cost.Georgia /Florida high heat high humidity? I would go Pentosin….way cheaper than replacing a ps pump due to heat issues. I tested and developed cars for decades in AZ,GA,FLA, Alabama and Texas....viscometrics trump cheap anyday. And heat is an issue, SAABS have silly elevated under hood temperatures compared to N/A autos.
The visco index is still half that of Pentosin. However the thickness at 40C of Pentosin is double that of Dexron III and equal at 100C. So, I would say that Dexron III would flow better than Pentosin except under extremely cold conditions (sub-freezing).Then you should know -- the difference between Pentosin and DexIII is minimal -- except the cost.
285k miles on my 9K with original p/s pump and the cheapest dexIII I can find...