Hyundai / Kia 2.4L Theta II GDI Engine Best Oil Sweet Spot

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This REALLY depends on how you drive.
Shirt tripping use any 20 weight. Highway or longer city drives, 30mins, go for any 30 weight.
You would be surprised how long it takes oil to get to full operating temp. Not coolant......the oil.
Especially in cool to cold weather.
 
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I think in the case of these engines and many other GDI engines, swapping out the oil often is way more important than what oil or brand you use. You just need to get the fuel diluted oil out of there. I also don't think starting off with 0w20 or 5w20 helps out one bit if the engine will dump a bunch of fuel into it.
 
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5000mile / 6 months OCI with a round of intake cleaner spray & fuel injection treatment at each change.
Replace PCV valve, which is very easy to do on GDI/TGDI Hyundai & Kia every 15000 miles.
 

ChrisD46

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5000mile / 6 months OCI with a round of intake cleaner spray & fuel injection treatment at each change.
Replace PCV valve, which is very easy to do on GDI/TGDI Hyundai & Kia every 15000 miles.
*Got 40K miles on my Hyundai 2.4L and am going to replace the PCV valve ... I would think that every 15K miles just cleaning out the PCV valve with brake cleaner would be enough versus replacing at 15K miles ?
 
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*Got 40K miles on my Hyundai 2.4L and am going to replace the PCV valve ... I would think that every 15K miles just cleaning out the PCV valve with brake cleaner would be enough versus replacing at 15K miles ?
Consider how easy to change it and it only worth two cups of coffee on Amazon- I will just swap a new one. But 15k seems too short? If it's still clunking it should be good?
 

ChrisD46

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Consider how easy to change it and it only worth two cups of coffee on Amazon- I will just swap a new one. But 15k seems too short? If it's still clunking it should be good?
*I think it is now a good idea to change out the PCV valve earlier rather than later ... I just bought a long 21mm socket just for my Hyundai PCV valve . It really seems to be important especially for a GDI engine as the less oil fumes I can keep from creating carbon or oil burning - the better !
 
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*I have tested various 5W20 , 5W30 and 10W30 synthetic oils in my 2017 Hyundai Sonata 2.4L . With 5W 20 weight synthetic oils the 2.4L Theta II engine runs nice and free - but due to fuel dilution and potential rod bearing issues - the question of not enough film thickness is often discussed as these engines continue to fail , so no wonder Hyundai / Kia now have gone to 5W30 oils for more film thickness head room . So, next I have experimented with thick 5W30 synthetic oils which Hyundai / Kia have now turned to in this engine (up to cSt @ 100 degrees C 12.0) as well as thin 5W30 synthetic oils down to cSt @ 100 degrees C 9.8) . The verdict ? The best running 5W30 synthetic oils in my Hyundai 2.4L Theta II engine have a cSt @ 100 degrees C. of between 9.8 to 10.6 (PPPP 5W30 , Valvoline Advanced 5W30 and M1 5W30 EP) . When I use thicker 5W30 synthetic oils greater than cSt @ 100 degrees C. of 10.6 from 11.0 to 12.0 (QSUD 5W30 , M1 vanilla 5W30) , I notice the engine starts to strain more (especially when cold) and over all performance starts to suffer as if the engine is straining more to pump the thicker oils . Lastly , I have checked my gas mileage and approx. 1 to 2 MPG improvement with the thinner 5W30 synthetic oils with this engine . As with anything , variable do exist - I'm just throwing it out there that from my experience after almost 5 years with this engine the "Goldie Locks" sweet spot synthetic oil for this 2.4L GDI Theta IIGDI engine is to pick a 5W30 synthetic D1 / Gen 2 or 3 with a cSt @ 100 degrees C. of between 9.8 (PPPP 5W30) and 10.6 ... I myself feel the best compromise in this engine as far as protection cushion with performance considered over a 5K mile OCI are the Valvoline 5W30 Advanced / EP and the M1 5W30 EP with 10.5 and 10.6 cSt @ 100 degrees C. respectively .
Thanks for this post. I’ve been running errands Castrol Magnatec in my 17 Elantra 2.0 non DI or turbo and it seems ok. I use PUP 5/30 in my Jeep would this be the same in my car or PP just as good. I run a 5000mi OCI. Is that valvoline the new EP or will the regular synthetic work. Thanks for the post
 
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girlfriends 18 optima 2.4 gets quaker state 10-30 ultimate durability fake synthetic in Pa weather + uses NONE between specd changes!!
 

ChrisD46

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2,600 miles on my current fill of M1 5W30 EP : Gas mileage is great , the engine is peppy and with less oil consumption . Engine cleaning should be great as well . The Valvoline Advanced 5W30 EP is on deck for the next oil change - (specs look great for a DI engine) .
 

pbm

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My s-i-l bought a used 2013 Optima 2.4 for her daughter from a dealer when she lived out west. I started doing her oil changes about 20K ago (currently has 147K). According to the dipstick (yellow IIRC) it hasn't had a new engine installed. When I used 5w20 and 5w30 it was always a quart low when I would check the oil after a month or so (approx 1500 miles). The last time I went with 5w40 and it didn't use any oil in 5K. She hasn't mentioned any sluggishness etc...I think it will get 0w40 or 5w40 from now on.

PS: It's a shame Hyundai/Kia hasn't gotten their engine issues under control....I would have gotten a Kona rather than the Mazda CX-30 for my daughter if they had...
 
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2,600 miles on my current fill of M1 5W30 EP : Gas mileage is great , the engine is peppy and with less oil consumption . Engine cleaning should be great as well . The Valvoline Advanced 5W30 EP is on deck for the next oil change - (specs look great for a DI engine) .
Interesting. So which did you preferred more?
 

ChrisD46

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Interesting. So which did you preferred more?
I believe in the case of the Hyundai 2.4L GDI engine - the Valvoline Advanced or the even better Extended Protection in 5W30 is priced better and perhaps has the better add pack in it as compared to pricier M1 5W30 EP which has a low amount of PAO and no titanium . The M1 0W20 EP has a great add pack with good slug of PAO in the mix while the M1 5W30 EP is just not anything special for $29 per jug at WM . Even if the M1 5W30 EP had a better add pack - I won't be running long drain intervals in a GDI engine , so a waste of money for me .
 
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