Oil viscosity in warm climate
 

Good afternoon,

Just wanted to get your opinion on something. I live in the Caribbean so the temperature doesn't go lower than 70F. Would it be fine to use a higher viscosity oil like 5W-30 since I don't have to worry about cold temps?

You'll be fine with 5w30 but I'm from Florida and have had zero issues with running the recommended 0w30 in this climate.

Sydney Australia, 5w 30

Lowest temps I see are -2° C in winter during the night, highest is 45° C during the day in summer.

Average temps from 5° C to 30° C.

Oil viscosity in warm climate
 

Florida too here, I just switched to 0W-30:

https://smile.amazon.com/Castrol-062.../dp/B007G7PUMS

No, this was in Brooksville.

Thats what I do every spring/summer till fall, then back to 0w-20 for the winter months.

I believe that's what the manual recommends as well for hotter or more heavy duty use for this engine.

I use 5W30 Redline (Viscosity is only one index, HTHS plays also a huge role) in Greece, from -5 to 40+C, but bear in mind STI sells 5W40 even for spirited street driving and Motul 5W40 for track use if that matters!

Honest question:
As long as your thermostat is working, and the radiator fans kick in properly, what difference does this make if the ambient never drops to sub-zero?