My 07 Civic has 150,000 miles. The manufacturer recommends 5w20, but for the most recent oil change, the mechanic used 5w30. I assume they just did it because it was convenient, but I am wondering if it is actually a good idea to go for a thicker oil at this point. The car is getting older. The 8th gen. Civic is prone to engine problems, and I live in a hot climate (summer highs regularly exceed 100f (38c)). Any thoughts?
Your engine runs at around 200°F so your climate doesn’t change the oil recommendation. Neither does age. Stick with the recommended oil