My car runs with 5W-30 oil full synthetic, the auto store guys want me to put in a thicker 10W-30 oil, because of the summer “heat”, is this correct? - Quora
5W-20 vs 5W-30 vs 10W-30: What's the Difference? - AMSOIL Blog
5w30 vs 10w30: Can You Use 10w30 Instead of 5w30 in Your Car? – AutoVfix.com