I bought a 2021 Sonata as my new daily last year. 2.5T Smart Stream engine. It suits my needs in a daily driver. Owner's manuals says nothing but 0W30. Been using Mobil 1. Did an analysis at 27K. Oil and engine immaculate. I used Penzoil Ultra Platinum 0W40 in my previous daily. That engine was also immaculate at 100K when it was totaled.
I'm in Texas and moving back to Arizona in the spring. Both have summer weather temperatures at 100+ of course. 0W30 is rated at -35 to 86F. 0W40 up to 104⁰. I'm thinking of going back to 0W40. Good idea? I'm not overly concerned with Hyundai saying is specifies 0W30 only, considering they're allowing dealers to use 0W20 during the free maintenance. You'd think they'd be stricter with that considering the Theta II issues ..
I'm in Texas and moving back to Arizona in the spring. Both have summer weather temperatures at 100+ of course. 0W30 is rated at -35 to 86F. 0W40 up to 104⁰. I'm thinking of going back to 0W40. Good idea? I'm not overly concerned with Hyundai saying is specifies 0W30 only, considering they're allowing dealers to use 0W20 during the free maintenance. You'd think they'd be stricter with that considering the Theta II issues ..