One more bite at the 5w20 v. 5w30 debate:

[csandste]

I know we've been down this road before. Not allowed to change my own oil cause I'm a condo dwelling geezer. I have a two liter, direct injection HyunKia engine. No real indication of fuel dilution and I'm not planning on getting a lab report. I'm using SuperTech syn on a 6K oci in order to get the odometer to a number divisible by 5K. I have a nearby tire store and a fistful of $10 coupons (really slightly more than $15 when they get all the fees and taxes tacked on).

Currently running 5w30 on the ST syn, and have run 5w20 Maxlife and VWB all without incident.

For 5w30-- it's hot in Missouri, notice no mileage change, it's a d.i. engine, it's probably sheared down to 5w20 anyway.

For 5w20-- that's what it says on the oil cap, less viscosity improvers means more oily goodness, .001% more gas mileage will buy me a c-store hotdog annually and I should take it.

I'm going in next week, using my Valvoline Conventional for $10 coupon (hopefully they won't reject me since VWB is shifting over to semi-syn marketing), and realize this debate has gone on before (and checked out those threads). Wide vs. narrow, thick vs. thin are ongoing debates on here. One more time-- just like a set list for a classic rock band full of 70 year olds.

 

[mrjlube]

Id stick with 5w20 if that is the recommendation. 5w20 oils have been proven over and over again. Even in the hot Florida summer a 5w20 will protect that engine just fine. I have seen many cars with 200,000 miles using only 5w20. Stick with 5w20 in your choice of brand and sleep easy

 

[buster]

It really depends. We're seeing more GDI engines that are prone to fuel dilution. Unless you're using a 5w30 that has little to no VII's, you're likely better off with a good 5w20. Valvoline Full Synthetic 5w20 is a nice choice as the Noack is around 7.5% and the sulfated ash is also low. I'd recommend that or if you have expensive taste for high end, try the new Valvoline Modern Engine 5w20 oil.

 

[csandste]

Originally Posted by buster
It really depends. We're seeing more GDI engines that are prone to fuel dilution. Unless you're using a 5w30 that has little to no VII's, you're likely better off with a good 5w20. Valvoline Full Synthetic 5w20 is a nice choice as the Noack is around 7.5% and the sulfated ash is also low. I'd recommend that or if you have expensive taste for high end, try the new Valvoline Modern Engine 5w20 oil.


Nah, Modern Engine not available at this tire store and I'm going to run through my fifteen or so $10 oil change coupons and change at 5K. The regular full syn would run me about four times as much even with the coupon.

 

[spasm3]

I'm not sure that a 20wt is more resistant to viscosity loss from fuel dilution than a 30wt. My stuff gets 30wt.

 

[Cujet]

Originally Posted by csandste
One more time-- just like a set list for a classic rock band full of 70 year olds.


Those concerts are still fun for this old geezer!!!! Love 'em.

With the very clear empirical evidence of oil related Hyundai/Kia engine failures, I'd stick with a robust oil and change it frequently. Other forums have some pretty epic threads on this, and the failure modes are known to be oil related, regardless of what the manufacturer claims.

In South Florida, there are a number of vehicles that have oil related troubles, mostly due to design. The solution is always the same, and it's never a thinner oil or an extended oil change interval. Never.

 

[buster]

Originally Posted by spasm3
I'm not sure that a 20wt is more resistant to viscosity loss from fuel dilution than a 30wt. My stuff gets 30wt.


The larger the spread the more VII's are used.

 

[CharBaby]

As mrjube said, not only are the 5W20 oils proven, they're proven because they're made better than they ever were in the past. Better base stock of oil and additive package.

 

[wemay]

2018 KIA Sportage 2.4L...
Running QSAD (conventional) 5W-20 right now in South Florida and have zero concerns for the 4.5 - 5K miles it'll be in the sump.

 

[csandste]

OK-- Side question.

If 5w20 is so great, why does GM stick with 5w30 as the backbone for it's Dexos (and pre-Dexos) oil recommendations?

 

[wemay]

Originally Posted by csandste
OK-- Side question.

If 5w20 is so great, why does GM stick with 5w30 as the backbone for it's Dexos (and pre-Dexos) oil recommendations?


Who knows, ask GM. No one said 5w20, 30 or other viscosity is "so great" either. They're saying 5w20 will work just fine in Florida. If you need more viscosity for piece of mind, 5w30 will work fine too.ðŸ‘

 

[csandste]

Originally Posted by wemay
Running QSAD (conventional) 5W-20 right now in South Florida and have zero concerns for the 5K miles it'll be in the sump.


Quick question--and I haven't checked the recommendations for the 2 liter turbo-- if I had di and a turbo I'd be running syn too. Does Hyundai recommend 5w30 and if 5w20 holds up better (because of less vi) why not go for 5w20 syn in that too?

 

[JLTD]

 

[4WD]

Well my Silverado and Tahoe are 0w20 Dexos …
not suggesting you use that … but not sure what you mean by the question

 

[Cujet]

Let's look at the problem of premature wear objectively. Manufacturers have produced engines with highly loaded, but relatively low quality, components for well over 100 years now. The classic flat tappet example is the one most commonly cited. Flat tappet engines survive due to sufficient viscosity, very modest oil temperatures, robust additive packages and so on. Chevy V8 timing chain wear is another classic example. Where the aftermarket industry created all sorts of products to mitigate premature failure in anything more than pedestrian use. (oil viscosity and oil change interval are key components here)

Today, nearly all engines use the very same timing chain designs used by Chevy 60 years ago. And the very same lubrication requirements exist. ie, clean oil of sufficient viscosity is important. (Chains last longest with 30 viscosity oil)

Modern engines are still very conventional engines and our great grandfathers would instantly recognize the working parts. Such as 3 ring high compression pistons, cast iron bores, very highly loaded connecting rod bearings, camshafts driven by long chains and camshafts operating flat or roller followers.

It's no surprise that when minor design issues exist, a contaminated thin oil is not up to the task and the result is often premature wear.

Ford's 5.4L is a great example of what happens to an engine when the oil is so thin it escapes out of the oil pump backing plate and under the timing chain tensioners, leading to near complete oil starvation on the Left cylinder head. Is it a bad design, or does the engine design simply require sufficient viscosity to maintain oil pressure? Maybe that depends on whether you want to spend $3K installing aftermarket parts which allow the use of thin oil. I choose 10W-30 M1 High Mileage w/5K OCI's. It's no surprise I'm having no troubles.

It's no surprise that BMW and Hyundai both have similar looking con rod bearings.

 

[spasm3]

Originally Posted by buster
Originally Posted by spasm3
I'm not sure that a 20wt is more resistant to viscosity loss from fuel dilution than a 30wt. My stuff gets 30wt.


The larger the spread the more VII's are used.



I agree in the sense of typical shearing. But is fuel dilution the same as VII shearing?

 

[wemay]

Originally Posted by csandste
Originally Posted by wemay
Running QSAD (conventional) 5W-20 right now in South Florida and have zero concerns for the 5K miles it'll be in the sump.


Quick question--and I haven't checked the recommendations for the 2 liter turbo-- if I had di and a turbo I'd be running syn too. Does Hyundai recommend 5w30 and if 5w20 holds up better (because of less vi) why not go for 5w20 syn in that too?


I've used both in the 2.4L NA. There are plenty anecdotes on both sides of the oil type argument where I'm comfortable running only conventional in my location if need be. The recommended viscosity for the 2.0T are 5W-30 and up. No 20.

 

[demarpaint]

I'd run 5W30 in it.

 

[PimTac]

"Today, nearly all engines use the very same timing chain designs used by Chevy 60 years ago. And the very same lubrication requirements exist. ie, clean oil of sufficient viscosity is important. (Chains last longest with 30 viscosity oil) "




I remember seeing timing chains on older cars that were wider and beefier. Today's timing chains look more like heavy duty bicycle chains. So is the design really the same?

 

[aquariuscsm]

If it were mine I'd use 10W30. Look in your manual to see if it lists one of those various viscosity charts according to temp and usage.