Originally Posted by KCJeep
I have used Castrol 0w40 in our Kia (with the V6 predecessor to your engine) and you can't tell one whit of difference in the way it runs from 5w20. I am out of warranty though, Kia does not allow 0w oils. Anyway I'd not be afraid of a good 5w40 at all.
I think my next change will be 5W-40 since I also heard a lot of good things about it in really hot weather and It's cheaper than 5W-30, so I think I will stick with 5W-40. My Grand Cherokee uses 0W-20 and I don't know how they are using such oil in extremely hot weather.
I have used Castrol 0w40 in our Kia (with the V6 predecessor to your engine) and you can't tell one whit of difference in the way it runs from 5w20. I am out of warranty though, Kia does not allow 0w oils. Anyway I'd not be afraid of a good 5w40 at all.
I think my next change will be 5W-40 since I also heard a lot of good things about it in really hot weather and It's cheaper than 5W-30, so I think I will stick with 5W-40. My Grand Cherokee uses 0W-20 and I don't know how they are using such oil in extremely hot weather.