is there any benefit of going 'thicker' if uoa already checks out?

[apollo18]

0w20 uoa came back good for my vehicle, so it had me thinking that i could bump up to a 0w30 to definetly be protected and have no worries incase of any fuel dilution or shear. however is there a benefit to bump up to a w40 weight? or would it be redundant since i am already protected at the w20 and going up to the w30 gives me some leeway?

curious to hear thoughts!

 

[hemioiler]

The experts here (doesn't include me) will tell you that UOA's are for telling you the state of your oil, not the state of your engine.

Lots of thick vs thin discussions on this forum if you search for them.

Exhibit A:

how come so many people change to a thicker oil or think there oil is too thin?

Sorry to bring this up if its already been spoken about. So what I have read is that a 5w20 is usually just oem fill for most vehicles because apparently they can save about 1% of fuel economy compared to a 5w30 oil and that big difference across there entire fleet results in meeting the...

bobistheoilguy.com

 

[JavierH19]

It could be good for oil consumption if you have any.

 

[92saturnsl2]

More specifics would help. Vehicle, mileage, oil, change interval and so on.

If the 0w-20 is working for you, why switch? Personally I go a grade above mfg recommended because I truly believe these thin oils exist because of CAFE / fuel economy considerations, with engine protection playing second fiddle.

So if it's a hobby for you, go ahead and experiment. If not, stick with the mfg recommendation and drive on. Odds say that you'll get tired of the car and sell it, wreck it, gets stolen, or a half dozen other things that send cars to graveyards, long before the engine calls it quits because of using manufacturer recommended oil.

 

[RDY4WAR]

If the 0W-20 is already providing sufficient film thickness to keep the bearings and crank journals separated, promoting good journal centricity and stability, then going to a thicker oil film won't benefit anything. You can't subtract from zero. If there's already no contact, with full hydrodynamic lubrication, then you aren't going to get any less contact.

What will happen is an increase in hydrodynamic friction (fluid friction), slightly reduced flow through the bearing, and increased bearing heat from that combination of increased friction and reduced flow. You'll also take a very small hit in fuel economy. That said, it won't be enough to matter in terms of wear or lifespan of the engine in a daily commuter. The fuel economy would be well within a margin of error. It's more of a footnote than anything but still something.

Speaking of oil consumption, going to a higher viscosity oil isn't always the answer for that. I've seen on multiple occasions where oil consumption has increased with a higher viscosity oil due to the thicker oil film promoting more oil transport past the rings. It really depends on the condition of the engine related to the consumption and where it's happening.

I would continue using the 0W-20 with confidence. As far as fuel dilution and shearing, if that's a major concern for you, I would rather use a better quality oil formulated to better handle fuel dilution and not shear.

 

[Cujet]

The experts here (doesn't include me) will tell you that UOA's are for telling you the state of your oil, not the state of your engine.

UOA results do not measure engine wear rates. I clearly understand the various firms selling the UOA service claim otherwise.

Wear is physically measured. Often with exotic equipment.

 

[56Cummins]

Are you tempted to use the same oil in a 30w and do another uoa? It won't definitively prove anything, but it would be interesting.

 

[cheesepuffs2]

UOA results do not measure engine wear rates. I clearly understand the various firms selling the UOA service claim otherwise.

Wear is physically measured. Often with exotic equipment.

This needs to become universally accepted here in my opinion. This idea that people see the PPM of iron in their UOA and have a sense of confidence about engine wear is rubbish.

 

[JohnnyJohnson]

I

What will happen is an increase in hydrodynamic friction (fluid friction), slightly reduced flow through the bearing, and increased bearing heat from that combination of increased friction and reduced flow.

Any idea of how many nanometers of lost flow we might expect?

 

[MSCH]

UOA results do not measure engine wear rates. I clearly understand the various firms selling the UOA service claim otherwise.

Wear is physically measured. Often with exotic equipment.

or a micrometer.

 

[dnewton3]

You can certainly change to a thicker lube.

But, it won't matter. It's unlikely to change any wear trends. Further, it probably won't change your costs, as most grades are the same price for any one product line.

Changing inputs with no correlation to any change in outputs means it's moot.

Do what you want.

 

[Jackson_Slugger]

UOA results do not measure engine wear rates. I clearly understand the various firms selling the UOA service claim otherwise.
.
Wear is physically measured. Often with exotic equipment.

They certainly do measure wear rates, the issue is that they are useless for doing so in the typical residential application done very periodically. Heavy equipment manufacturers use them as do the commercial operators for long drain applications every OCI which is where they can be valuable...

As for the OP, no you're not going to gain anything in an application calling for a 0W-20 if using a quality oil meeting all spec's...

 

[gfh77665]

Climate?

0-20 might be perfect for you. OTOH, in the southern US I don't think 0-20 is optimal. Of course nothing will "blow up" but I do believe the CAFE 0-20 oils are not optimal across the blazin' hot south.

 

[edyvw]

Climate?

0-20 might be perfect for you. OTOH, in the southern US I don't think 0-20 is optimal. Of course nothing will "blow up" but I do believe the CAFE 0-20 oils are not optimal across the blazin' hot south.

Can you please explain us that theory? Oil temperature is maintained by cooling system in majority of vehicles, in some with external oil cooling radiator(s) and in some with combination pf heat exchangers and radiators.
Southern US is low altitude, therefore absolutely not an issue to keep optimal temperature.

 

[gfh77665]

Can you please explain us that theory? Oil temperature is maintained by cooling system in majority of vehicles, in some with external oil cooling radiator(s) and in some with combination pf heat exchangers and radiators.
Southern US is low altitude, therefore absolutely not an issue to keep optimal temperature.

I am not going to get into yet another Thick vs. thin debate. That horse has been beaten well past "to death". I also don't really care what anyone uses in their personal vehicles. Opinions were solicited, and I gave mine.

Common sense is not a "theory". No one should use 20w-50 in North Dakota. Likewise, 0-20 has little or no benefit (other than CAFE!!!) in the deep south. Why would anyone need a "0" if it never gets cold? Finally, there has been ample screenshots posted of manufactures recommending somewhat higher viscosity oils for hard use applications. Do the math.

 

[tolian21]

The only advantage of going thicker if you got one of those Honda DI engines that drops your viscosity due to fuel

 

[edyvw]

I am not going to get into yet another Thick vs. thin debate. That horse has been beaten well past "to death". I also don't really care what anyone uses in their personal vehicles. Opinions were solicited, and I gave mine.

Common sense is not a "theory". No one should use 20w-50 in North Dakota. Likewise, 0-20 has little or no benefit (other than CAFE!!!) in the deep south. Why would anyone need a "0" if it never gets cold? Finally, there has been ample screenshots posted of manufactures recommending somewhat higher viscosity oils for hard use applications. Do the math.

I am not going into thin vs. thick debate.
I am just telling you that "blazin' hot" is irrelevant. 110 degrees in Texas is less taxing on engines than 80 degrees over Vail Pass. So, ambient temperature is irrelevant. The cooling system will keep the optimal temperature. Also, living in Deep South does not mean anything "harder." Just bcs. you are hot, but that does not mean the engine has an issue.

Why no 10W20? Maybe, just maybe, the logistics of running 0W20 in Alaska and Florida.

I agree about CAFE, but that as not the point I was making.

 

[hemioiler]

UOA results do not measure engine wear rates. I clearly understand the various firms selling the UOA service claim otherwise.

Wear is physically measured. Often with exotic equipment.

I have no firm opinion on this as I'm not qualified to have one.

But I have seen reports where iron/copper has increased in hemi's, followed by lifter failure and replacement. It would appear that at least sometimes increased wear metals may be an indication of imminent failure. Afterall, there are hundreds/thousands or UOA's showing decreasing wear metals as an engine goes from "new" to "broken in", why would it be impossible for the reverse to be noticed?

 

[gfh77665]

I am just telling you that "blazin' hot" is irrelevant. 110 degrees in Texas is less taxing on engines than 80 degrees over Vail Pass.

Engine temps far exceed "110 in Texas". The real issue is starting temps. Thats where viscosity really matters.
As I said, there is simply no need for a "0" if you don't have cold weather. Huge benefit in ND, zero benefit where I Iive.
All I say is use whatever viscosity is best suited for your application. I don't believe 0-20 is optimal for everyone.

 

[Cujet]

The only advantage of going thicker if you got one of those Honda DI engines that drops your viscosity due to fuel

There seems to be a lot of this going around. That is not backed up by the studies, or any number of real world results. There are studies showing just the opposite. Not to mention far more rapid timing chain wear with ultra low viscosity oils. Wear rates most certainly are affected by viscosity.