Another "Taxi" Study: Relationship of Engine Bearing Wear and Oil Rheology 872128

[TiGeo]

That seems to be the part people don't seem to comprehend ... seems they think just because it "seems top still runs good" that it must still be in stellar shape. That's not always the case.

But this is my hang up - it's often the case. Yes, all the science shows that you get more wear using the thinner oils and less efficient oil and air filters. But, the question for me is whether a vehicle with a less efficient filter(s) and thinner oil run well with no measurable ill-effects for the normal time folks own them with these vs. using thicker oil and higher efficiency filters? I'd say sure. So then what does it matter? That is the crux of this (for me) and the testing is hard to do to ever show it. 10 years/125K on 5W20 and a K&N air filter in my Ford Focus. No oil consumption. Great running car. Is tuned for more power. Spent a lot of it's life in low-load highway commuting but also has had the snot beaten out of it by my teenage son. So did I do worse b/c of it than if I used a Motorcraft paper air filter and 5W30 over that time? Did I gain an marginally tiny improvement in mpgs that over 10 years adds up to something not so marginally small?

So my summary of all these recent threads (before it gets locked which I'm sure is about to happen in 3...2...1...ahhahaha) is...does the increase in wear (the engineering/science proves this beyond a reasonable doubt is true is what I read here) from running an oil with a lower viscosity matter in the "real-world" that most of us live in?

 

[TiGeo]

Even if HTTS above some magical number creates less wear - will anyone ever realize the benefit of that lower wear number?

Is my primary question in this discussion.

 

[Bill7]

It's about engine condition/health at 400K (or even 100K, 200K) ... not that it just "made it" there. I highly doubt an engine not designed to run on 0W-16 or less is going to be in the same mechanical health/shape as one running xW-30 or xW-40.

A possible way to measure that is oil consumption. My expectation is that engine wear implies oil consumption, and that oil consumption at high miles will always be higher with thin oils.

 

[TiGeo]

Nothing "bad" about a little thicker oil expect maybe a sliver of less fuel mileage.

Can you quantify "sliver"?

 

[Bill7]

It won't tell anyone anything unless there is an outright engine failure, or the oil filter keeps getting visible metal debris - which was already detected after the first oil change with only 1000 miles. If there is no blatant detection of engine damage going on, the only "conclusion" in this "test" is that it worked. But in reality, even if "it worked" there will be no way to actually tell if and how much the wear was increased because the monitoring methods to a baseline are not sophisticated enough.

Guys are running 100s of miles on old beater cars on YouTube on WD-40 (search if on YT), and only get them to blow-up after they put a brick on the gas pedal and let the engine bounce off the rev-limiter for 3~4 minutes. If they didn't blow it up on purpose and just drove it for 1000s of mile, the engine wear would certainly be increased from running a lubricant that thin.

The fact that Ali is seeing visible wear metal debris in the oil filter after 1k miles with 0W-5 oil in an engine designed for 5W-30 is already proof that thin oils are dangerous. I believe we're all waiting for the UOA results he sent in. My expectation is it will show astronomical wear metals. Maybe Ali's next several 1k OCI's can be with 0W-8 with an UOA, followed by 0W-16 with an UOA, followed by 0W-20 with an UOA, followed by 5W-30 with an UOA.

 

[TiGeo]

I personally want my vehicles to reach 200k/300k/400k miles with zero engine wear/zero oil consumption,
so I use oil with HTHS = 3.2. If my vehicles unexpectedly get severe service during a long trip (like going up long inclines in
slow moving traffic due to an accident up ahead), and engine temperatures are rising, I know my engine wear remains 0 for that trip.
But if I had oil with HTHS = 2.3 in the engine, I would honestly be worried about any severe service causing engine wear.

Note, in the Toyota owner's manuals for cars with ultra thin oil, they admit that for severe service like driving at extended high speeds, that a thicker oil may be more appropriate. That shows that even the engineers realize thin oil can't handle severe service.
So if that is the case, why use thin oil at all, as cars can unexpectedly reach severe service on any trip.

How can you have "0" engine wear?

I think most people's definition of "severe service" is WAY less severe than what it really is to cause issues and the engine/oil in these cars that recommend thin oils more than cover the situations that average people would think are severe.

 

[ZeeOSix]

... does the increase in wear (the engineering/science proves this beyond a reasonable doubt is true is what I read here) from running an oil with a lower viscosity matter in the "real-world" that most of us live in?

It depends on how thin you go, the use condition, engine maintenance, etc, etc. It's all about mitigating wear to ensure the engine stays in good health, for reliability and longevity. Bottom line is protecting the engine from wear by using oil and filters that give more protection isn't some rocket science that's going to cost a fortune to do. Some people take like to operate that way, some don't ... that's all up to them of course. Some people don't care much about their vehicles except that it still runs and gets them from point A to point B regardless of what shape it's in. These discussions are focusing on what can cause more wear and what can be done to mitigate that and keep an engine in the best condition possible over it lifetime of use.

 

[TiGeo]

The fact that Ali is seeing visible wear metal debris in the oil filter after 1k miles with 0W-5 oil in an engine designed for 5W-30 is already proof that thin oils are dangerous. I believe we're all waiting for the UOA results he sent in. My expectation is it will show astronomical wear metals.

This is such an extreme case, of course it's doing that, it's 0W5. Now what if he was more reasonable and ran 5W20. I'd think there would be effectively no difference detected in UOA, the filter, or tear down over a normal life of the engine which this slightly thinner oil. I believe Ali understands this and his whole point is to say that sure, your car calls for 30W and you run 40W? Cool. You can also run a 20W and it will also be fine.

 

[ZeeOSix]

Can you quantify "sliver"?

Not enough to accurately measure while driving a car around on the streets in an everyday normal manner. If I didn't go through the gears to near redline just one time less per tank full, I'd probably save more fuel on that tank of gas than I would by running a grade thinner oil.

 

[TiGeo]

Not enough to accurately measure while driving a car around on the streets in an everyday normal manner. If I didn't go through the gears to near redline just one time less per tank full, I'd probably save more fuel on that tank of gas than I would by running a grade thinner oil.

I still want to see the data man...how much does a 20W save me over a 30W over 10years/125K on average? It's got to be a fraction of a mpg right? How much extra power/efficiency is gained?

125K @25mpg @$3/gal is 15K in fuel I've put in that car. If I got 0.5mpg more on average using 20W vs. 30W, I save $295 so call it 1 car payment. I get it, it not much, but it's real just like the additional wear I got from not using 30W is real. Reality is probably less than 0.5 mpg so even less money for my mega-TacoBell run!

 

[TiGeo]

It depends on how thin you go, the use condition, engine maintenance, etc, etc. It's all about mitigating wear to ensure the engine stays in good health, for reliability and longevity. Bottom line is protecting the engine from wear by using oil and filters that give more protection isn't some rocket science that's going to cost a fortune to do. Some people take like to operate that way, some don't ... that's all up to them of course. Some people don't care much about their vehicles except that it still runs and gets them from point A to point B regardless of what shape it's in. These discussions are focusing on what can cause more wear and what can be done to mitigate that and keep an engine in the best condition possible over it lifetime of use.

If two engines, one with 20W and one with 30W run over 100K were compared...would anyone be able to tell which was which w/r to "good health"?

 

[ZeeOSix]

... whole point is to say that sure, your car calls for 30W and you run 40W? Cool. You can also run a 20W and it will also be fine.

Depends on the use conditions in that case. Putting a 20 in an engine calling for a 30 and going to a track day isn't gonna be a good decision ... putting the 40 in would be the good decision. Cruising around in a mellow way, not a problem. Could probably put WD-40 in it to just go cruising around in a benign way, but more wear going on there - someone would have to be pretty obtuse to claim using WD-40 in an engine doesn't cause any more wear, lol. Go find that YT where the guys put WD-40 in a Ford Probe.

 

[Bill7]

I still want to see the data man...how much does a 20W save me over a 30W over 10years/125K on average? It's got to be a fraction of a mpg right? How much extra power/efficiency is gained?

125K @25mpg @$3/gal is 15K in fuel I've put in that car. If I got 0.5mpg more on average using 20W vs. 30W, I save $295 so call it 1 car payment. I get it, it not much, but it's real just like the additional wear I got from not using 30W is real. Reality is probably less than 0.5 mpg so even less money for my mega-TacoBell run!

But any tiny fuel efficiency gains would be offset by having to buy more top off oil as engine with more wear with the thinner oil would be burning more oil.

 

[ZeeOSix]

If two engines, one with 20W and one with 30W run over 100K were compared...would anyone be able to tell which was which w/r to "good health"?

Again, depends on the use conditions. If 20K of those miles were hard use conditions where the engine was pushed hard, then there certainly could be some measurable differences (compression, oil burning, HP on the dyno, emissions level, etc).

How about if the engine used 0W-16 or less when it's specified to use xW-30. Think it would be in the same shape? I don't.

 

[TiGeo]

But any tiny fuel efficiency gains would be offset by having to buy more top off oil as engine with more wear with the thinner oil would be burning more oil.

My Focus isn't using any top off oil and has no consumption so that's all my money baby.

 

[Bill7]

I still want to see the data man...how much does a 20W save me over a 30W over 10years/125K on average? It's got to be a fraction of a mpg right? How much extra power/efficiency is gained?

125K @25mpg @$3/gal is 15K in fuel I've put in that car. If I got 0.5mpg more on average using 20W vs. 30W, I save $295 so call it 1 car payment. I get it, it not much, but it's real just like the additional wear I got from not using 30W is real. Reality is probably less than 0.5 mpg so even less money for my mega-TacoBell run!

Would anyone know of any test results comparing the long term engine wear of 5W-20 versus 5W-30.

 

[userfriendly]

When I break it down it looks something like this per month:

Car/truck payments about $1,300 has been my MO for the last 20 years.
Fuel $300 minimum. More if I'm working 24/7.
Insurance $200
Tires n' wheels $200 (295/65/20s are expensive, but I'm small package compensating)
Engine oil and other fluids & filters $20

That puts me at $2,020 a month.
Using thinner fluids like 75W90 instead of 80w140, LV ATF, and engine oil may save me $20/month.
That's a deck chair blowing off the Titanic.

 

[OVERKILL]

This is such an extreme case, of course it's doing that, it's 0W5. Now what if he was more reasonable and ran 5W20.

Right, but that's the point that's been expounded on what has to be 100x already. There's that "magic" HTHS figure, which is somewhere in the neighbourhood of 2.5cP and once you go below that, you are looking at fundamental design changes in order for us to even reach the threshold of "adequate" wear control. He's running an oil with an HTHS below 1.6cP, yeah, it's not surprising we are seeing metal.

So, it's not about "reaching zero" or that 2x a tiny number is still a tiny number. Sure, that might be the case going from 2.6cP in your 5W-20 to 3.0cP in an ILSAC 5W-30, that, overall, there's really no meaningful difference to Average Joe, but that's not what is being discussed and that's certainly not what is going on when you are literally seeing metal chunks in the oil filter.

So, if we are specifically referring to Ali's experiment and not the paper in the OP, then the research from the Honda paper applies, and that is simply that engines require specific design accommodations/alterations in order for wear to be acceptable once you drop below the xW-20 grade; below the ~2.5-2.6cP HTHS realm. His Navigator does not feature an engine configured in this manner. Ergo, any justification that might be applicable to the discussion between say xW-20 and xW-30, xW-40...etc doesn't apply, this is a wholly separate realm that requires mechanical design changes and that bit seems to be getting glossed over.

 

[OVERKILL]

assumptions...
Didn't Neo have a 0W-5 when the lowest grades were xW-20? I recall it wan't much thinner, if any, than a 20.

Was the KV100 of that oil published? Is so, where did it come in w/r to the KV100 grade range for 0W-8? If it came in below the low end of 0W-8 KV100 (below 4.0 cSt), then it's probably why they called it a 0W-5 ... even though SAE J300 doesn't recognize that grade.

Yes, I think it came out before the J300 updates for xW-16, xW-12 and xW-8 were made (or at least the last two there). But it was very much a 0W-20 IIRC.

 

[userfriendly]

Right, but that's the point that's been expounded on what has to be 100x already. There's that "magic" HTHS figure, which is somewhere in the neighbourhood of 2.5cP and once you go below that, you are looking at fundamental design changes in order for us to even reach the threshold of "adequate" wear control. He's running an oil with an HTHS below 1.6cP, yeah, it's not surprising we are seeing metal.

So, it's not about "reaching zero" or that 2x a tiny number is still a tiny number. Sure, that might be the case going from 2.6cP in your 5W-20 to 3.0cP in an ILSAC 5W-30, that, overall, there's really no meaningful difference to Average Joe, but that's not what is being discussed and that's certainly not what is going on when you are literally seeing metal chunks in the oil filter.

So, if we are specifically referring to Ali's experiment and not the paper in the OP, then the research from the Honda paper applies, and that is simply that engines require specific design accommodations/alterations in order for wear to be acceptable once you drop below the xW-20 grade; below the ~2.5-2.6cP HTHS realm. His Navigator does not feature an engine configured in this manner. Ergo, any justification that might be applicable to the discussion between say xW-20 and xW-30, xW-40...etc doesn't apply, this is a wholly separate realm that requires mechanical design changes and that bit seems to be getting glossed over.

That sums it up. Yea, no more thick vs thin threads.
Overkill, ZeeOsix and a few others went to a lot of work and effort posting on this thread.
It's been one of the best in years on bitog.