[GeoCanada]

I have the SX model (1.6L Turbo)

The oil cap states 5w-30
The manual states 5w-30 or 5w-40
The Kia website states 5w-30

I've had a total of 4 oil changes since owning the vehicle (over a year).
The dealership has been putting in 5w-20
Does anyone have any thoughts? Understanding of this?
Looking online lots of oil forums are saying 5w-20 is bad for turbo GDI engines.

Any insight would be appreciated.

 

[Hamster-GT]

Find another dealer. The dealer i used to go to used 5W20 in my turbo Forte. It's supposed to be 5W30 or 5W40 in the turbo engines.

 

[Chappy]

Yep my selling dealer was going to charge me extra for synthetic if I wanted it on a nc first service. After a short email exchange where I stated the sx 1.6 turbo calls for synthetic, he agreed and I got my nc service. They also use Petro Can synthetic oil which as far as I can tell is not ACEA A5 certified like manual states. I perform my own maintenance, that I enjoy doing, so with all the misinformation from dealer's I'm not concerned with warranty disputes,

 

[TheWasteHandler]

If the manual and everything else says 5W30, run what it says. Inconsistent or incorrect oil weights aren't good for the internals and won't provide the right protection on engine internals, leading to damage...

Me personally, I've used Mobil 1 synthetic in everything I've owned since 2000 - including a '92 GMC Typhoon 4.3L V6 Turbo, '07 Impala SS w/ the 5.3L LS4 V8, and a '12 Buick Regal GS Stage 1 2.0L H.O. Turbo.

 

[CYANiDE]

I run 5W-30 Edge on our SX Turbo. 10 minutes oil changes in my driveway.

 

[Old Car Nut]

Like @TheWasteHandler I've been a long time fan of Mobil 1 full synthetic. I had a borescope examine the inside of our dearly departed Rav4 when it had over 90k miles on it, and also the LS3 that puts out about 470 HP at the crank and over 10k track miles, and both still show the honing marks on the cylinder walls. Compression and leakdown on my LS3 with a total of 48k miles still exceeds new specifications so no ring wear despite hard, hard usage.

I had a turbo car a long while ago - a Ford Probe from 1989 that had the 2.2 liter turbo 4 that was a Mazda engine. I installed a "turbo timer" from a company called HKS which would allow me to shut off the car and remove the keys but allow the engine to idle for an additional preset time before shutting down. That engine was modified to produce about 50% greater boost than stock and survived to 80+k miles without any signs of wear from the turbo. I used a 5w-30 as the higher hot viscosity was said to prevent coking of the turbo bearings. I sold that car to my sister who drove it for many additional years and no issues.

5w-20 has been recommended in other modern cars like my daughter's BMW and my son's Honda. When I change their oil, it flows out like it's water, and as an old guy, that just doesn't feel right. I get that fuel economy is important, but I personally would sacrifice a little fuel efficiency for better shear and film strength.

 

[TheWasteHandler]

Like @TheWasteHandler I've been a long time fan of Mobil 1 full synthetic. I had a borescope examine the inside of our dearly departed Rav4 when it had over 90k miles on it, and also the LS3 that puts out about 470 HP at the crank and over 10k track miles, and both still show the honing marks on the cylinder walls. Compression and leakdown on my LS3 with a total of 48k miles still exceeds new specifications so no ring wear despite hard, hard usage.

I had a turbo car a long while ago - a Ford Probe from 1989 that had the 2.2 liter turbo 4 that was a Mazda engine. I installed a "turbo timer" from a company called HKS which would allow me to shut off the car and remove the keys but allow the engine to idle for an additional preset time before shutting down. That engine was modified to produce about 50% greater boost than stock and survived to 80+k miles without any signs of wear from the turbo. I used a 5w-30 as the higher hot viscosity was said to prevent coking of the turbo bearings. I sold that car to my sister who drove it for many additional years and no issues.

5w-20 has been recommended in other modern cars like my daughter's BMW and my son's Honda. When I change their oil, it flows out like it's water, and as an old guy, that just doesn't feel right. I get that fuel economy is important, but I personally would sacrifice a little fuel efficiency for better shear and film strength.

But that's the thing with all these newer engines, they don't need the heavier 10W oil to get the same coverage, protection and lubrication that older engines used to...

The one thing that still gets me - especially with these newer DI engines, is how the oil always smells heavily of fuel... the LHU 2.0L H.O. in my former Regal was the first I noticed it, amd the Seltos is the same way when I checked the oil on it last week...

 

[Old Car Nut]

But that's the thing with all these newer engines, they don't need the heavier 10W oil to get the same coverage, protection and lubrication that older engines used to...

The one thing that still gets me - especially with these newer DI engines, is how the oil always smells heavily of fuel... the LHU 2.0L H.O. in my former Regal was the first I noticed it, amd the Seltos is the same way when I checked the oil on it last week...

I wasn't very clear - my response was really to the "30" part of a 5w-30 oil, compared to the "20" in a 5w-20. My understanding is that number represents the viscosity at 100 degrees C. and that in general, high viscosity at 100 degrees C. also represents an increased resistance to coking in turbos. Added shear strength comes partly from just a thicker film itself, so the extra mass of the thicker oil coating the parts also helps to prevent the entire oil film from being destroyed.

Being an old guy, I still take hints from that racing oils tend towards higher viscosities so if I want the type of protection that would be typical of a motor used to its thermal extremes, that I should use a thicker oil (at 100 degrees C) as well. So I'm not a fan of any "20" weight oil and would never use less than a "30" weight oil in any car I own. And even then, the 5w-30 and 0w-30 Mobil 1 synthetic oils are towards the lower end of the "30" weight anyway.