I am currently running the recommended Castrol GTX 5W-20. I premix with Protech-R. If I go to 5W-30 during the summer months here in Florida does that effect how clean the oil burns off thus effecting the life of my cat? I know this is kind of an oil thread, but I am concerned about the viscosity of the oil in the summer months.

 

Yes, oil threads get closed pretty quickly.

No, the oil weight you use does not affect the cleanliness of the burn OR the life of the cat. The weight on the bottle is for 32F and 100F ratings. Combustion temps are a bit higher than this, making all viscosity meaningless in the combustion chamber.

In Florida, you can use 10w40 all year round.... Or 0w40 if you think cold starts need to be better.


Beyond this, you have to make up your own mind. Asking for oil opinions is asking for a million things that you can't choose between.