5w20 vs 5w30

[KCJeep]

Originally Posted By: AuthorEditor

Case in point were Crown Vics and the Mercury Grand Marquis. Used the same engine for many years and one year Ford changed their recommended lube to 5W-20 from 5w30.


We still have many Crown Vics in our fleet at work that have run their whole life on 5w20 conventional. If you look in the fill hole they are varnished up pretty good and they tend to develop significant consumption at right about 120k. I don't know if the 5w20 is to blame for this or not, but they would have had a good 30 grade in them if they were my cars.

 

[Vuflanovsky]

I'm much more interested in the chemistry/qualities of the oil versus barking out that a 0w-20 or 5w-20 is CAFE driven...as if that's some tacit opinion that these oils will always be inferior to in every application. Ridiculous.

The thick vs. thin arguments undoubtedly will have someone putting 10w-40 in a Ow-20 spec'd vehicle because he doesn't buy into the CAFE-driven conspiracy that will have his engine dying 100K miles earlier, so he needs to "protect" it. I wonder how many of these same people still want to use SG oils versus SN oils because they don't have that "fuel conserving [censored]" associated with them.

 

[KrisZ]

Originally Posted By: tig1
Originally Posted By: Gene K
Assuming HT/HS follows I can prove 30 grade is better at higher sump temps. However for typical street use it's likely a non-issue.


It is a non issue because Mobil 1 0w20 will not oxidize up to nearly 500F.


HTHS and oxidation are two totally different and unrelated things. An oil with HTHS viscosity of 3.0 (no matter the SAE designation) will protect better at high temperatures than an oil of HTHS viscosity of 2.6 (no matter the SAE designation).

That is why SAE designations are almost useless. But at least it keeps BITOG busy with 20vs30 debates.

 

[asker123]

Originally Posted By: KrisZ


HTHS and oxidation are two totally different and unrelated things. An oil with HTHS viscosity of 3.0 (no matter the SAE designation) will protect better at high temperatures than an oil of HTHS viscosity of 2.6 (no matter the SAE designation).

That is why SAE designations are almost useless. But at least it keeps BITOG busy with 20vs30 debates.


Ok so here is data from Mobil 1 website

Mobil 1 5W-20
SAE Grade 5W-20
Viscosity @ 100ºC, cSt (ASTM D445) 8.9
Viscosity, @ 40ºC, cSt (ASTM D445) 49.8
Viscosity Index 160
Sulfated Ash, wt%, (ASTM D874) 0.85
HTHS Viscosity, mPa•s @ 150ºC (ASTM D4683) 2.75
Pour Point, ºC (ASTM D97) -43
Flash Point, ºC (ASTM D92) 230
Density @15º C g/ml, (ASTM D4052) 0.852

Mobil 1 5w30
SAE Grade 5w30
Viscosity @ 100ºC, cSt (ASTM D445) 11.0
Viscosity, @ 40ºC, cSt (ASTM D445) 61.7
Viscosity Index 172
Sulfated Ash, wt% (ASTM D874) 0.8
HTHS Viscosity, mPa•s @ 150ºC (ASTM D4683) 3.1
Pour Point, ºC (ASTM D97) -42
Flash Point, ºC (ASTM D92) 230
Density @15.6 ºC, kg/l (ASTM D4052) 0.855


What you mentioned is that just look at HTHS which definitely better in 5w30 ( 3.1 compared to 2.75 of 5w20) but what about Viscosity @ 100ºC or Viscosity, @ 40ºC , those are much low for 5w20 rather than 5w30

In layman language I understand by viscosity is how well an oil flows so what if thicker oil will not pass through the holes inside the engine ..I mean crankshaft, timing chain and what not... and what if the thicker oil not reach to the overhead cam that well.....

 

[Shannow]

Originally Posted By: asker123
In layman language I understand by viscosity is how well an oil flows so what if thicker oil will not pass through the holes inside the engine ..I mean crankshaft, timing chain and what not... and what if the thicker oil not reach to the overhead cam that well.....


Nope, they are being driven there by an oil pump that is positive displacement...at either 40, or 100C there will literally be no time difference between them reaching the top end on a start.

And when running, there "may" be a flow volume difference, but bearings only draw that oil which they need to replenish side leakage (more viscosity, less leakage, less make-up requirement and flow).

Flow doesn't lubricate.

 

[Tony10s]

Originally Posted By: KCJeep
There is very little a 5w20 will do that a 5w30 won't do as well or better. About the only possible advantage to the 5w20 is cold starts and it is small, you can easily find 5w30's with better cold crank abilities than say a 5w20 conventional. I will take the 5w30 thank you.

I prefer 5w30 over 5W-20 as well.



_________________________
Quaker State (Quaker State Advanced Durability/ Quaker State Conventional) 5w30
Hastings/Baldwin Oil Filters
Hastings/Baldwin Engine Air Filters

 

[tig1]

Originally Posted By: AuthorEditor
Quote:
Also CAFE does not require 0-20 oils.

I think the argument is that to meet "fleet" standards car manufacturers changed specs to 5W-20 in order to tweak fuel economy slightly higher for their line up. Fueling this theory was the fact that many vehicles went from specing 5w30 one year to 5w-20 the next year with no change in engines.


If that were the case, why doesn't all engines in the US require 20wt oils?

 

[Shannow]

Originally Posted By: tig1
If that were the case, why doesn't all engines in the US require 20wt oils?


Strawman...

CAFE requires economy standards.

Review their own documentation, and they state that viscosity is one of the most cost effective ways of doing it...subject to the manufacturer satisfying themselves that any reduction in life is acceptable.

Review their documentation and they also give credits for backspeccing.

Review their documentation, and if a manufacturer chooses viscosity as a route of meeting the standards, that they must make every reasonable means to ensure that the end user doesn't change their oil back to something else. Oil grade on fill cap is something that most global markets DON't have. Single grade in mnauals are all a part of it.

Back to the strawman. Because some OEMs choose NOT to follow that path is not proof that the trend in other OEMs is not CAFE driven (or carbon fines in other markets).

 

[Garak]

Originally Posted By: Shannow
the ILSAC grades are and were "EC"...same mother just older.

In fairness to GM, though, they've been pushing the thinner 30 grades for a very, very long time, even without government encouragement. Paradoxically, though, they hung onto the 30 grades longer than almost anyone else.

As for the argument as to why not all engines in the U.S. require a 20 instead of a 30, take a look at the ones remaining that do specify a 30 grade. Aside from those that have good engineering reasons to do so, many of those that stick to a 30 are fairly low volume vehicles.

 

[Gene K]

Originally Posted By: tig1
Originally Posted By: Gene K
Originally Posted By: tig1
Originally Posted By: KCJeep
There is very little a 5w20 will do that a 5w30 won't do as well or better. About the only possible advantage to the 5w20 is cold starts and it is small, you can easily find 5w30's with better cold crank abilities than say a 5w20 conventional. I will take the 5w30 thank you.


So what's the advantage of a 30wt over a 20wt then? I may very well have been using 0-20 longer than most here,(used Mobil 1 5w20 in the late 70s in an engine calling fo 10-30) and have found it to be outstanding in all temps. I like the way my engines start in cold temps and perform in hot temps. My engines use no oil between OCIs and both are very clean through the oil fill hole, so the 20wt isn't showing any signs of oxidizing, or do my engines show signs of wear. This is all at 10K OCI's. Now if my engines called for a 30wt then I would use 5-30 in this day and age. You simply can't prove your point that a 30wt is better for your engine if it calls for a 20. Now opinions are just that, opinions.


Assuming HT/HS follows I can prove 30 grade is better at higher sump temps. However for typical street use it's likely a non-issue.


It is a non issue because Mobil 1 0w20 will not oxidize up to nearly 500F.


I was thinking more of viscosity at 300F sump temps on track.

 

[ChrisD46]

For vehicles calling for 5W20 on the oil fill cap , I REALLY like everything about Mobil 1 Advanced Fuel Economy 0w20 oil.

 

[dblshock]

if 30 is better than 20 then 40 is better than 30.

 

[Shannow]

Originally Posted By: dblshock
if 30 is better than 20 then 40 is better than 30.


another strawman ... but at operating temp, yes the 40 will have higher MOFT in the areas lubricated hydrodynamicaly and the boundary/mixed areas will be closer to hydrodinamic.

now you need to define "better" in terms of NPV WRT overall operating costs and the regulatory environment.

 

[tig1]

Originally Posted By: Shannow
Originally Posted By: tig1
If that were the case, why doesn't all engines in the US require 20wt oils?


Strawman...

CAFE requires economy standards.

Review their own documentation, and they state that viscosity is one of the most cost effective ways of doing it...subject to the manufacturer satisfying themselves that any reduction in life is acceptable.

Review their documentation and they also give credits for backspeccing.

Review their documentation, and if a manufacturer chooses viscosity as a route of meeting the standards, that they must make every reasonable means to ensure that the end user doesn't change their oil back to something else. Oil grade on fill cap is something that most global markets DON't have. Single grade in mnauals are all a part of it.

Back to the strawman. Because some OEMs choose NOT to follow that path is not proof that the trend in other OEMs is not CAFE driven (or carbon fines in other markets).


Doesn't prove that it does either. Just one reason I like 20wt oils is the faster delivery of oil to the cam and chain area in very cold temps. Here's a video showing painfully slower oil reaching the cam in cold temps.

https://www.youtube.com/watch?v=OWiQyR7PWII

 

[asker123]

Originally Posted By: tig1

Doesn't prove that it does either. Just one reason I like 20wt oils is the faster delivery of oil to the cam and chain area in very cold temps. Here's a video showing painfully slower oil reaching the cam in cold temps.

https://www.youtube.com/watch?v=OWiQyR7PWII


Good video.. Explains things visually...
I am running 5 w 20 in my accord and I use Mobil 1 . I typically change only twice a year ( six months OCI) because I do not do 8000 KM in 6 months. and I am in Canada.
So even if I will change my oil in Beginning of June when tep is bit high over here too , the oil will continue in engine till beginning or mid Dec and here in Canada sometimes from mid Sep onwards morning and evening temp start to dip down and typically from monday to friday that is the only time I run the car that too for short trip of 7 kms
Seems all in all I dont have any sign of 5w30 protection benefit to me so I think I will stick to 5W20...

Just a question - people here say 5W30 put in summer will sheer down to 5W20 by fall...Then will the 5W20 not sheer to 5W10 ? If that way engine oil sheers down then we are only running the grade we put in for first few months , then after it is running as one grade less... Is there any truth in it?

 

[KrisZ]

Originally Posted By: asker123
Originally Posted By: tig1

Doesn't prove that it does either. Just one reason I like 20wt oils is the faster delivery of oil to the cam and chain area in very cold temps. Here's a video showing painfully slower oil reaching the cam in cold temps.

https://www.youtube.com/watch?v=OWiQyR7PWII


Good video.. Explains things visually...
I am running 5 w 20 in my accord and I use Mobil 1 . I typically change only twice a year ( six months OCI) because I do not do 8000 KM in 6 months. and I am in Canada.
So even if I will change my oil in Beginning of June when tep is bit high over here too , the oil will continue in engine till beginning or mid Dec and here in Canada sometimes from mid Sep onwards morning and evening temp start to dip down and typically from monday to friday that is the only time I run the car that too for short trip of 7 kms
Seems all in all I dont have any sign of 5w30 protection benefit to me so I think I will stick to 5W20...

Just a question - people here say 5W30 put in summer will sheer down to 5W20 by fall...Then will the 5W20 not sheer to 5W10 ? If that way engine oil sheers down then we are only running the grade we put in for first few months , then after it is running as one grade less... Is there any truth in it?


It's a very misleading video as proven by your and tig's reaction.
In order to understand what is shown in the video, you have to first understand the oil cold pumpability requirements and how the oils get their winter "W" ratings.

Basically in the video they tested two oils with different "W" ratings but at the temperature that is perfectly suitable for the 0W oil (-35C), but not suitable for the 5W oil (or was it 10W? I don't remember). The same would happen to the 0W oil if the temperature was lowered beyond its rating. Also, both oils would reach the top equally fast if the temperature was raised to where the 5W or 10W is rated for.

It is not a proof of anything, but the fact that the winter rating the oils get is spot on.

EDIT:

What they showed in the video would be the same in concept as putting a Corolla against a Challenger SRT8 on a drag strip and after the Challenger has won, proclaiming that it is proof that the Challenger will get you faster to work in everyday traffic.

 

[69GTX]

Originally Posted By: tig1
Doesn't prove that it does either. Just one reason I like 20wt oils is the faster delivery of oil to the cam and chain area in very cold temps. Here's a video showing painfully slower oil reaching the cam in cold temps.

https://www.youtube.com/watch?v=OWiQyR7PWII


If they used a 5w-20 vs. 5w30 oil in that video, there would have been very little difference in the flow to the cams. What they did was compare a 0w-20 to a 10w30 at -35c. What does that have to do with comparing 5w's which was what this thread is about?

They could have also shown a 0w-20 vs. 0w30 in that example. And again, the difference in oil showing up at the first cam would be negligible. If cold flow is a concern, you could run a 0w30 instead of the 5w-20...getting both ends covered.

My 2002 Lincoln 4.6L is back spec'd to 5w-20. Those identical engines from 1996-2000 ran just fine on 5w30, the grade that the ENGINEERS designed it for. I run 5w30. My 1997 got to 230K miles on 5w30 before it rusted out.

 

[demarpaint]

Originally Posted By: 69GTX

If they used a 5w-20 vs. 5w30 oil in that video, there would have been very little difference in the flow to the cams. What they did was compare a 0w-20 to a 10w30 at -35c.



Pretty easy actually. Setup the test to prove the outcome you're after or pay for it and get the results you want. Comparing a 5W20 to a 5W30, or a 0W20 to a 0W30 wouldn't have yielded the results they were after.

 

[bbhero]

You know better than this.. That it's the W rating that dictates cold temp flow. Let's measure the film thickness of a 20 viscosity HTHS of 2.6 versus a 30 HTHS of 3.1 at operating temps. Having stated this, the 20 viscosities with such strong base stocks and additive packages can work almost just as well as a 30 operating viscosity. Today at this point with the advances that have been made I believe that the difference is very slight indeed. I ran the recommended 5w20 in my Ford Fusion. I usually ran Castrol gold bottle 5w20 or Valvoline Synpower 5w20 for 5k. If I had a Ford Fusion again with a 5.5 qt capacity with the 3.0 motor I would do that again. But IF I had the 3.5L VQ motor in a 2016 Nissan Altima I would likely run a 5w30 full synthetic. It is a 3.5L motor vs the 3.0 with a smaller sump size (4.9 qts vs 5.5 qts)and very well known to be very hard on oil vs a motor that's much easier on oil. It's all a matter of application and how it all fits together. Now, I could possibly run a 0w20 IF it had a higher than average HTHS like Redline typically does.

The "cold" flow would not be an issue for a vast majority of the time and place here in the US to begin with.

 

[tig1]

Originally Posted By: demarpaint
Originally Posted By: 69GTX

If they used a 5w-20 vs. 5w30 oil in that video, there would have been very little difference in the flow to the cams. What they did was compare a 0w-20 to a 10w30 at -35c.



Pretty easy actually. Setup the test to prove the outcome you're after or pay for it and get the results you want. Comparing a 5W20 to a 5W30, or a 0W20 to a 0W30 wouldn't have yielded the results they were after.


In the video they compare 15-40 to 0-30. Some here say the oil flow to the head is the same for either. That's bunk. Thinner oils flow much faster than thicker oils as proven by the video.