Originally Posted By: ChrisD46
Sayjac: On one hand you have 5W20 stamped on the oil fill cap and then as you coreectly stated the nebulous high temperature statement in the owners manual . Seems like I could run 5W30 in the Summer / Fall and 5W20 in the Winter/Spring . To date , I have run 5W20 VWB , PYB , FS , MC Syn Blend and QSAD at 4K OCI's all year long because it seemed the right thing to do .
When I posted my recommendation, I did so based on my experience using 5w20 in two other spec'd vehicles, one since 01 (Civic), and my reading on the subject here over time. The post directly above (Patman's) pretty much summarizes what that reading has been.
As for Hyundai's vague OM sentence, frankly until it was pointed out yesterday I can't remember seeing it. I saw the chart and that is what I was going by. IMO, unless the engine is being subjected to regular towing and/or racing (WOT), the ambient temp in Atlanta wouldn't be a factor in using 5w20. In other words, with an average load, using 5w20 year round should work fine. Plus the benefits at startup and mpg (however small), tend to favor 5w20. And any of the 5w20 oils used for 4k OCI's would all be fine if not a tad conservative on the oci.
All that said, if running 5w30 in the summer makes you feel more confident, or for whatever reason, it's your vehicle. I just gave my answer to the question of what I would run and why.