*If true , then why did Hyundai issue the TSB stating more or less - if you don't want to have your engine grenade then you should move up an oil grade ?
Originally Posted by Gokhan
0W-20 has a thinner base oil than 5W-20, in fact often a lot thinner. In the valvetrain, timing chain, and parts of the rings and liners, the base oil is all that matters and the viscosity modifiers that thicken the oil have no effect. A 5W-20 can be formulated with very little viscosity modifier, sometimes none at all. 5W-20 is often the thickest oil as far as the base oil is concerned, as 5W-30 needs to use thinner base oils to meet the MRV specs, as more viscosity modifiers make the MRV worse. So, for many applications except those demand thick oils (HTHSV = 3.5 cP or higher), 5W-20 is the sweet spot for protection against wear, surpassing both 0W-20 and 5W-30. https://www.bobistheoilguy.com/foru...
Originally Posted by Whammo
I have a 2012 Kia optima and the Manual allows 5w20, 5w30 or 10w30 but doesn't say anything about 0w20 or 0w30. Is there any reason these wouldn't be suitable for this 2.4 L GDI engine?