Hi, guys.
I need immediate advice on engine temperatures and oil viscosity.
I have 96 Kia Sportage 2.0 DOHC engine. During normal driving temperature stay very still. But when it's hot outside (it now in Bay Area) above 90, temperature starts rising rapidly, especially in city driving. I'm not even talking about using AC. Temperature jumps even faster. Temperature stays above normal even on a freeway during hot day with AC on.
I'm using Mobil 1 15W-50. Manual allows using 10w-40 and 20w-50 in hot climates.
What puzzles me is that it's the Mazda's engine, which also went on Ford Probe in 90's and both Ford and Mazda recommend using 5w-30 or 10w-30 in it.
Do you think that the temp will go down if I switch to Amsoil 10w-40? Have you ever had this kind of experience? Have you ever switched to lighter grade and noticed temp drop?
I know that it might be a thermostat. But why temp is normal when it's a bit colder outside. If you think I should change thermostat which temp should I pick? Standard is 192. Should I go with 180? I'm using Dexcool mixed 50/50 do you think that it's the right coolant for this car?
Thank you,