Is the recommended 0-20 bad for engine life?

[Mephy]

And is a recommendation based on political influences rather than technical. The vehicle warranty is based on oil-related engine damage. No one is going to damage their engine by using an oil of a somewhat higher HT/HS as long as the winter rating is appropriate for the starting conditions.

A 20-grade oil is adequate for most engines under most circumstances. This is evidenced by many manufacturers back-specifying the grade to some older models. But as has been shown on here multiple times is that an HT/HS of 2.6 (20-grade) is the inflection point for increased wear without design modifications. This is what resulted in ILSAC GF-6B oils being given a different classification.

So are they "bad"? No, not bad. Are they generally adequate for many vehicles? Yes. Will a higher HT/HS oil damage the vehicle? No. Will a higher HT/HS decrease wear? Yes. How much and when is the debate, but it's still there.

You said right is based more on political influence .

 

[C6 Modellsport]

My two cents: Use what is called for. Someone way better at math than you and I designed these engines and spec'd oil weights for them. My engine calls for straight 30w general use so it gets 10w30. My challenger calls for, and gets, 5w20.

 

[BornSlippy]

My two cents: Use what is called for. Someone way better at math than you and I designed these engines and spec'd oil weights for them. My engine calls for straight 30w general use so it gets 10w30. My challenger calls for, and gets, 5w20.

Except that argument falls apart when manufacturers recommend thicker oil in other parts of the world for the exact same engine.

Usually the rebuttal to that is, climates are different in other parts of the world.

In North America, you have the same variance in climate as anywhere else in the world.

0W-20 is 0W-20 no matter if it's in Phoenix or Edmonton.

 

[Jimmy_Russells]

Except that argument falls apart when manufacturers recommend thicker oil in other parts of the world for the exact same engine.

Usually the rebuttal to that is, climates are different in other parts of the world.

In North America, you have the same variance in climate as anywhere else in the world.

0W-20 is 0W-20 no matter if it's in Phoenix or Edmonton.

There can be several reasons for different requirements. Fuel quality, sulfur level, sandy environments, average speeds, etc.

 

[C6 Modellsport]

Except that argument falls apart when manufacturers recommend thicker oil in other parts of the world for the exact same engine.

Usually the rebuttal to that is, climates are different in other parts of the world.

In North America, you have the same variance in climate as anywhere else in the world.

0W-20 is 0W-20 no matter if it's in Phoenix or Edmonton.

And if I take a picture of the oil chart in the manual for my 71 C10 it shows everything from 10w to 50w depending on duty severity and time of season. They put a dozen different conditions on six grades of single weight oil in there to choose from! And yes, I do have mine, though sitting in the glovebox for 53 years has made it insanely delicate.

Again, they're way smarter than we are and they did math we can't comprehend. If they say it needs 0w20 it needs 0w20.

Hell the only reasons I'm not running straight 30w in my C10 is because 10w30 is much more readily available and is the recommended general usage oil for 250 I6s produced after multiweight oils became commonplace. Rather convenient that it acts like a 10w when cold, though.

 

[SubieRubyRoo]

3,030 recent threads

That’s only the thick vs thin threads. Once you include the thin vs thick threads, the count nearly doubles…

 

[kschachn]

And if I take a picture of the oil chart in the manual for my 71 C10 it shows everything from 10w to 50w depending on duty severity and time of season. They put a dozen different conditions on six grades of single weight oil in there to choose from! And yes, I do have mine, though sitting in the glovebox for 53 years has made it insanely delicate.

Again, they're way smarter than we are and they did math we can't comprehend. If they say it needs 0w20 it needs 0w20.

Hell the only reasons I'm not running straight 30w in my C10 is because 10w30 is much more readily available and is the recommended general usage oil for 250 I6s produced after multiweight oils became commonplace. Rather convenient that it acts like a 10w when cold, though.

No engine "needs" a 20-grade. Every engine needs an oil with a minimum HT/HS to prevent excessive wear, but you can always use a higher grade.

And it's not about the engineers recommending a grade per any requirement other than political, that ship sailed years ago. Now the EPA dictates that whichever grade was used to obtain fuel economy figures must be what's listed in owner materials. In fact those letters also require the automaker to actively and vigorously discourage the use of any other grade.

Engineers are spending their time designing engines that tolerate thinner grades without excessive wear. But the days of "optimal" are way gone. Doesn't mean you can't successfully use what's recommended, but it's not a matter of "need".

 

[RobbyDawg]

My friend has about 320k on his 2014 Sierra 5.3l running 0w20, either Mobil1 or NAPA, whichever is on sale at the time. Changes it according to OLM. Not sure much more could be expected using a thicker oil.

Nice…any lifter failures?

I ask bc I have the same truck with 89k and only use 5w-30

 

[Rutwad01]

Nice…any lifter failures?

I ask bc I have the same truck with 89k and only use 5w-30

Knock on wood, no. I was guessing at the mileage. But checked last weekend and he is at 315k. He has replaced valve cover gaskets because they were leaking. And a few months ago it had a chirping sound when he first cranked it cold. He was thinking lifters. His transmission was also shuddering. We changed his transmission fluid and filter and the chirping went away. It's been a good truck for sure

 

[Nessism1]

No engine "needs" a 20-grade. Every engine needs an oil with a minimum HT/HS to prevent excessive wear, but you can always use a higher grade.

And it's not about the engineers recommending a grade per any requirement other than political, that ship sailed years ago. Now the EPA dictates that whichever grade was used to obtain fuel economy figures must be what's listed in owner materials. In fact those letters also require the automaker to actively and vigorously discourage the use of any other grade.

Engineers are spending their time designing engines that tolerate thinner grades without excessive wear. But the days of "optimal" are way gone. Doesn't mean you can't successfully use what's recommended, but it's not a matter of "need".

Plain bearings are feed by oil under pressure, and the bearing clearance is well established based on age-old equations. Tighter clearances require thinner oil. Try to stuff a thick oil into a bearing with tight clearance, and the bearing will fail.

It's not just a matter of the EPA driving thin oil, the entire engine is designed to use thinner oil.

 

[Jetronic]

Plain bearings are feed by oil under pressure, and the bearing clearance is well established based on age-old equations. Tighter clearances require thinner oil. Try to stuff a thick oil into a bearing with tight clearance, and the bearing will fail.

It's not just a matter of the EPA driving thin oil, the entire engine is designed to use thinner oil.

But you use a thick oil every day.... the bearings don't care it's only 40F in the morning. And you can't stuff the oil in the bearing with the little pressure the il pump provides, you just present the oil to the bearing.

Besides, look up bearing clearances in workshop manuals, for an older engine speccing a 30 or 40, and for a recent engine speccing a 20 or below. Prepare to be amazed....

 

[stwremains]

And is a recommendation based on political influences rather than technical. The vehicle warranty is based on oil-related engine damage. No one is going to damage their engine by using an oil of a somewhat higher HT/HS as long as the winter rating is appropriate for the starting conditions.

A 20-grade oil is adequate for most engines under most circumstances. This is evidenced by many manufacturers back-specifying the grade to some older models. But as has been shown on here multiple times is that an HT/HS of 2.6 (20-grade) is the inflection point for increased wear without design modifications. This is what resulted in ILSAC GF-6B oils being given a different classification.

So are they "bad"? No, not bad. Are they generally adequate for many vehicles? Yes. Will a higher HT/HS oil damage the vehicle? No. Will a higher HT/HS decrease wear? Yes. How much and when is the debate, but it's still there.

this!

 

[stwremains]

Except that argument falls apart when manufacturers recommend thicker oil in other parts of the world for the exact same engine.

Usually the rebuttal to that is, climates are different in other parts of the world.

In North America, you have the same variance in climate as anywhere else in the world.

0W-20 is 0W-20 no matter if it's in Phoenix or Edmonton.

for instance my Subaru specs 0W20 for the entire continental USA but yet specs 5W30 in Japan (till the most recent model, where I believe Japan now also specs 0W20)

 

[stwremains]

But you use a thick oil every day.... the bearings don't care it's only 40F in the morning. And you can't stuff the oil in the bearing with the little pressure the il pump provides, you just present the oil to the bearing.

Besides, look up bearing clearances in workshop manuals, for an older engine speccing a 30 or 40, and for a recent engine speccing a 20 or below. Prepare to be amazed....

TL;DR - tolerances aren’t as different or “tighter” as is often claimed.

 

[SubieRubyRoo]

Tighter clearances require thinner oil. Try to stuff a thick oil into a bearing with tight clearance, and the bearing will fail.

Do tell… bearings now fail from being prevented from achieving contact with rod and/or main journals during operation?

 

[userfriendly]

Yyyyyes and no….

Good luck with a warranty claim on a vehicle with an oil cap and manual specifies 0W20, and you’ve been using 10W50

I agree that using one or two steps higher to provide proper protection rather than go along with the mpg frenzy that thinner oils surround, it likely wouldn’t cause a warranty issue if it was even determined that a thicker oil grade was used…

So if the radio quits working you won't get it fixed on warranty if the engine has 10w50 oil instead of the grade written on the cap?
I'd just change the cap to match the engine oil.
Besides, there was a topic thread that asked the question if anyone had an engine replaced or repaired on warranty, or if they, or anybody they knew had warranty denied?
If I remember correctly, the topic ran for pages with no examples, just rabbit holes and was eventually locked.
It appears to me that people who post about how thin an oil they run are virtue signaling.

 

[picklyrickly1073]

So if the radio quits working you won't get it fixed on warranty if the engine has 10w50 oil instead of the grade written on the cap?
I'd just change the cap to match the engine oil.
Besides, there was a topic thread that asked the question if anyone had an engine replaced or repaired on warranty, or if they, or anybody they knew had warranty denied?
If I remember correctly, the topic ran for pages with no examples, just rabbit holes and was eventually locked.
It appears to me that people who post about how thin an oil they run are virtue signaling.

Is there a thread for all of the failed engines that call for 0w-20 and ran 0w-20? It appears to me that most people here are virtue signaling with their thickness (and not always oil).

 

[hrv]

Is there a thread for all of the failed engines that call for 0w-20 and ran 0w-20? It appears to me that most people here are virtue signaling with their thickness (and not always oil).

Yup 7 pages so far and I think the answer is NO... Just like all the failed engines...NOT...with the Orange Can of Death...

 

[picklyrickly1073]

Yup 7 pages so far and I think the answer is NO... Just like all the failed engines...NOT...with the Orange Can of Death...

Everyone swears the lochness monster is real even though nobody has ever seen it. There’s def reasons to go thicker (I did) but I hate when people turn that into outright lies about thin oils being inadequate

 

[tolian21]

My the fuel dilution in my Acura RDX reduces viscosity by 2 or more cSt in 0w-20. The Xw-30 is needed just to keep oil in grade of 0w-20.