2003 used Tribute with over 140,000 miles.

Ford Duratec 3.0L V6 engine

I bought it a year ago and have no clue what type of oil was used in it.

Currently, I am using Castrol GTX Trishield 10W-30 conventional oil.

I live in a hot tropical climate with ZERO cold weather.

I am wondering if I should try and get some expensive 5W-30 or 5W-20 synthetic oil now?

 

I've been running nothing but 100% synthetic 5w-20 in mine for well over 100k with no issues and it purrs like a kitten. Just tore it down for a power adding rebuild and the internals are spotless.

 

Thanks for the reply.

I was asking because my vehicle is out of warranty and has HIGH mileage of over 140,000 miles on it. My climate is VERY HOT and humid and tropical.

I thought those factors would play a role in my choice of oil. I guess not?

If I have any loose gaskets or engine bearings then the 5W-20 will make it known.

 

Castrol GTX High Milage