Kia 3.8L V6 - Lighter Grade Oil Better ?

[KCJeep]

Ours is a 2012, also says 5w20 on the cap to satisfy the CAFE Nazi's. The manual quickly suggests 5w30 or 10w30 if any real work is to be done (like driving in high heat or towing) and allows for even thicker oils if it's all that's available.

The Hyundai/KIA 5w20 spec has long reeked of "me too" CAFE stuff and IMO has nothing to do with the engines, which doesn't take a genius to figure out when you read the manual. They won't grenade on a 20 grade of course, but if you carefully peruse UOA's you'll see the aluminum numbers usually higher with 20 grades. People fixate on the iron numbers but it's my observation the thinner oils show up in the aluminum numbers first.

I have run a 5w20 a couple times in winter when I got a smoking deal...but ours has seen 5w30 almost exclusively the last 65k. But I switched to 10k OCI's recently and in went Castrol 0w40, guess what it runs great you can't tell any difference.

 

[Kuato]

The whole "small oil passages" thing is nonsense.

Take a look at what is recommended in Australia and you'll see that 5w30 will be fine. -20 will probably be ok also.

 

[SHOZ]

My Gen Coupe turbo came with 5w20 and that is what the oil cap said. They quickly changed their tune with the 2011 models but did not inform owners.

 

[ChrisD46]

5W20 , 5W30 and 10W30 are allowed according to ambiant temps (per the OM) ; Hyundai / Kia never have endorsed a 0W oil .
Originally Posted By: FordCapriDriver
Originally Posted By: ChrisD46
Oil Cap = 5W20
**Any truth to this engine having "narrow" oil passage ways thus 5W20 is preferred ?
Will also note this engine has a timing chain (not a timing belt) if that matters .

No, it's not due to small oil galleries, it's because of CAFE Governement fuel economy standards in the US.
As i said earlier, even though the oil cap says 5W-20, a 0W-30 or 5W-30 or even 10W-30 would not do it any harm.

 

[Brons2]

I've used 5w30, have had 3 Hyundai/Kia models, no issues.

 

[Linctex]

Originally Posted By: AnthemBassMan

I had an old 1978 Pontiac Grand Prix with the dog 301 v8 in it. Near the end of its life, I was running Kendall GT straight 70 weight oil because the engine was so worn out.


I had a dark red/maroon one!

When I'd drive it down University Drive in Fargo, people would say "I see they're fogging for mosquitoes again"!!

I think If I had a trap on the exhaust, I could catch some of the oil and pour it right back in. It used a quart every 15 miles.