Hi, I own a 2015 Toyota Highlighter with 134k miles and a 2016 Lexus RX 350 with 95k miles. They both have automatic transmissions. I’ve been reading the debate between using 0w-20 vs 5w-30 motor oil. Some claim it’s better to use 5w-30, especially when the engine has high mileage. I have always used 0w-20 for both cars as recommended by manufacturer. Should I switch both cars to 5w-30? What do you think on the subject?
FYI: I live in a city where summers get hot sometimes above 100 degrees F.
Should I switch both cars to 5w-30?
No
especially when the engine has high mileage
Do not adjust viscosity based on mileage. Adjust your service interval instead.
This question is answered in our FAQ (we've mentioned it to you before)
I have always used 0w-20 for both cars as recommended by manufacturer.
Good. You're always safe to go by this. The car was engineered to use it.
FYI: I live in a city where summers get hot sometimes above 100 degrees F.
Irrelevant. The engine operates at the same temperature anywhere on the planet, and you want the oil to be the least viscous as possible for cold startup.
