Viscosity Chart Revealing

[Fred Hammond]

Wow!!! You guys are the best. Thanks for all the info from my earlier post. Since my last reply, I found the Viscosity Grade Chart off of Bob's Home Page. Reviewing this chart open my eyes. If I quote something wrong, please correct me. From other posts, Moble One 5w30 has a Kinematic Viscosity of 9.7 cSt@100Deg C, Ford Motorcraft has a viscosity of 8.8 on the same scale. From Bob's Chart, the breaking point between 20 wt. and 30 wt. is 9.3.

Hmmmm, If my stated values are correct, M1 5w30 is a very thin 30 wt., darn near a 20 wt. No suprises, I all ready knew this from reading old posts. What I didn't realize was that the Motorcraft 5w20 was way high on the 20 wt. Bob' chart shows 20 wt. from 5.6- 9.29.

Folks, this dog ain't going to hunt. There just doesn't seem to be a significant difference between the 2 oils at operating temperture. I wish I could compare cold weather flowability of the Motorcraft 5w20 to M1 5w30 or M1 0w30.

By knowing how the Motorcraft 5w20 flows at cold temps, and since we know the viscosity warm, we should be able to gain more insight into Ford's thinking when they speced the 5w20.

Just looking at the viscosity numbers and the chart, and by using common sense, I feel more confident that the car buyer has been suckered. The upper viscosity values are close and surly M1 5w30 will flow better at start-up then any dino or blend 5w20. I realize that other 30 wt. oil are higher on the scale than M1 5w30, but it sure looks like Ford and maybe Honda could have allowed the use of Moble One 5w30 and any other 5w30 oils that are close to the M1 visocity. Is there an obvious reason why Ford couldn't have save all the money spent on developing their 5w20 and simply speced a synthetic oil like the M1 5w30 and still got the CAFE boost.

I don't mean to sound like a M1 5w30 salesman, I am currently using it in a 97 Towncar, mainly because I get it in 5-quart jugs for $17.84 ? at Wal-mart and they always have it.From what I have read, it seems to be popular and has good wear numbers, but not the best for extended intervals.

Can someone show me where my logic is incorrect or do you agree my thoughts have merit. As always, Your comments and feedback are appreciated. Fred

 

[shoz123]

It has been my expierence in the last 5 years that Ford doesn't pay much attention to logic.

 

[Jay]

Welcome to the wonderful world of motor oil specs where there's a bigger difference in viscosity between Amsoil's 5w-30 and Mobil 1's 5w-30 than there is between Mobil 1's 5w-30 and Amsoil's 5w-20.

I think that Mobil 1 5w-30 is the best oil value for 20-weight users right now. I may change my mind if I find a really good 20-weight that outperforms it.

 

[MavRick]

Fred,

Take a look at the following EPA Letter and it provides some more clues into Ford's motivation. I think the bottom line is that In order for Ford to get credit for the increase in MPG, the EPA had to believe it very likely that users would actually use the recommended product that had the improved gas mileage. If they spec'd 5w30, most likely people would buy whatever their favorite brand is and fuel savings aren't there.

Plus even though M1 and Motorcraft are close viscosity, Ford is looking at from .1% to 1% improvements, the avearge being 0.6%. These aren't even worth mentioning for an individual driver, but multiplied by 1000's it adds up to Fords CAFE credits.

I found it interesting reading. I also don't trust Honda saying in the letter they didn't switch for CAFE reasons since they recommend higher viscosity oils in Japan on the same engines.

 

[mdv]

Fred,

I think you need to add a qualifier in your first post. When NEW, there isn't much difference between Motorcraft 5W-20 and Mobil 1 5W-30. My big question is what and how fast will the 5W-20 shear to with use?

 

[Patman]

I don't think the 5w20s will shear back as much as the 5w30s do. They need less VII, plus in a lot of cases the 5w20s are using a better base oil too.

So far based on the reports we've seen on here, I don't recall any of the 5w20s thinning out further.

 

[kev99sl]

I have to jump up on my CAFE soap box here and ask, does anyone think that Ford and Honda modified their engines between model years in such a way that a thinner oil was needed in order to clear the tighter tolerances? If so, we need to talk, because I have some investment opportunities that I'm sure you'd be happy to partake in.

In other words, Honda didn't change THING ONE in their engines before they started requiring 5w-20. All they and Ford know is that you can probably run a 20 wt. oil for at least 100,000 miles without any major engine problems. If you want to get to 300,000 miles, 5w-20 will likely not get you there. The same type of shenanigans took place when everyone dropped to 5w-30. There are thinner oils that may protect an engine just fine, but if anyone thinks the primary consideration in switching down was engine protection, they're kidding themselves.

 

[Patman]

Kevin, I do realize that 5w20 was not born out of a need to protect engines better, but for better fuel economy.

But at the same time, I don't see it spelling the death of a pile of engines either. Carmakers are not that stupid.

Most 5w30 dino oils out there will thin out considerably under hard usage, and even more so if someone extends the interval beyond it's capability. But a better built 5w20 oil will remain in grade for longer, so in reality you might end up with better protection running this type of oil. Or at least the difference in viscosity between the two will be too close to call. One is on the high end of the 20wt scale while the other is on the low end of the 30. And yet we didn't see a rash of engine failures after 5w30 came out.

Sure, I'm not the biggest fan of 5w30 oils, however I have seen enough good 5w30 (and 5w20) oil reports that I'm not scared of these oils.

I think in time we'll see that what I'm saying is true.

 

[Patman]

Just to make things a little more clear here, I'm not telling everyone to go out and start using 5w20. I just think that if your warranty specifies you must use it, then give it a chance, run some oil analysis on it, and go from there. Once you are confident that the engine isn't going to have any serious issues, then you could go to whatever oil you want, keeping in mind that you might be giving up your warranty on it at this point.

 

[Whimsey]

I'm with Patman on this issue. For my 2002 F150 w/4.6L I've run the Motorcraft 5W-20 since new, changing @ 500 mi. first, then @ 2,500 mi odometer readings. Terry is doing a 10,000 mi. odometer reading analysis of the oil(about 2,500 mi on the oil) and he'll let me know if I can extend to 5,000 mi. If so then I'll have it tested again @ 5,000 mi. and see how it's wearing. At that point in time I'll see whether it's worth while to stay with it or maybe even go to the new Mobil 1 0W-20 or go to a synthetic 5W-30. I'll keep you guys informed.

Whimsey

 

[MavRick]

Whimsey, I look forward to your results. Have you monitored oil consumption and if so how much is it using? My new ford 4.0L V6 used 20 oz of Mobil 1 5w30 in 3000 miles.

 

[kev99sl]

quote:

---

Originally posted by Patman:
Just to make things a little more clear here, I'm not telling everyone to go out and start using 5w20. I just think that if your warranty specifies you must use it, then give it a chance, run some oil analysis on it, and go from there. Once you are confident that the engine isn't going to have any serious issues, then you could go to whatever oil you want, keeping in mind that you might be giving up your warranty on it at this point.

---

I want to make clear that I also agree that you should use the specified viscosity while the car is under warranty. It makes no sense to give auto makers a convenient excuse if something goes wrong with your engine while you're still covered by the warranty.

 

[Whimsey]

Giles, yes I've been monitoring the oil "usage" and it hasn't used any from day 1. My wife has a 2002 Exploder. I'm ashamed to say that I've not checked hers. She has the oil changed at the Dealer every 5,000 mi, I guess I'm going to check it asap, out of curiosity. She puts the miles on sooo fast!

As an aside I think that is one great vehicle , with the new SOHC 4.0L and 5 sp. auto. She had a '96 with the old pushrod engine and 4 sp auto, while good, NO comparison! I have a '96 contour that has run Mobil 1 5W-30 and other syns. It seems that when first changing to or back to the Mobil 1 it "uses" oil, not a lot but noticeable on the dipstick, 1/2 qt in 3000 mi. But after the second oil change with the Mobil 1 it stops using oil.

Whimsey

 

[metroplex]

Patman: carmakers ARE stupid. as long as the car lasts 100k-150k they're fine with whatever that can get 0.0000000005 better mpg.

They'll skimp out on a bolt or two just for the savings. THey want us to buy new cars every 3-5 years.

Why else would the same engine require two different weights all of a sudden?

It's like taking a 1981 302 V8 and saying all of a sudden that the 1982 302 V8 needs to use 5W-20.

The FOrd modular engine was almost born into the 5W-30 and 10W-30 line. It has proven that the -30 weight oils are FINE for the modular motors over the past 10+ years (1991 was the first year for the modular engine, IIRC). My new E-250 w/ the 5.4L SOHC V8 will NOT be using 5W-20. I'm dumping the factory fill ASAP and going to M1 5W-30 right away.

Motorcraft 5W-20 is nothing more than a synthetic blend. Yep that's right. Pure dino 5W-20 cannot withstand the abuse and Ford had to change to a synthetic blend.

 

[Patman]

But that's just it. There is no such thing as a pure dino 5w20 as far as I can tell. All of them are built with better base oils. So there is no point arguing that a 5w20 dino oil is no good if it doesn't exist.

Perhaps US automakers might be stupid in some ways (such as GM killing the f-body, a mistake I'll NEVER forgive!!) but Honda isn't stupid. They have a reputation for reliability that they don't want to lose. People buy Hondas based on word of mouth from other Honda owners. That's why I bought the 2000 Civic my wife drives. I knew lots of Honda owners who had good luck, so I took the chance.

 

[kev99sl]

quote:

---

Originally posted by Patman:
I don't see it spelling the death of a pile of engines either.

---

Not a pile of engines with 150,000 miles on them, if that's all you want out of your engine. But a modern engine should be able to last double that without so much as regular maintenance. Show me an engine that has seen a steady diet of 5w-20 for 150,000 miles, and one that started on 5w-30, moved to 10w-30, then 10w-40 as miles increased and I can almost guarantee that the 5w-20-fed engine will show markedly more wear, if it's still running without consuming 5 quarts between changes.

I will grant you that every engine is different, but an engine that is able to run 5w-20 past 200,000 miles is a credit to the engine maker, not the oil.

I don't suggest that everyone start dumping 20w-50 in their 1.5 liter 4-bangers as soon as they drive them off the lot, but simple physics dictates that thicker oils will protect better than thinner provided they can flow adequately in the environment present. When an engine is new, a 30-weight oil is likely plenty thick. Maybe anything thicker than that would have a hard time getting to where it needs to go. But I think a 40-weight will likely be just fine too in most cases. The same holds true for 20 wt. vs. 30 wt.: oil analyses that show 20 wt. oils holding their own in new engines will never address my complaint. You could run sewing machine oil or straight Marvel Mystery Oil in a new engine and probably get 50,000 useable miles out of it.

Besides, many current 5w-20 oils are a shade away from being 5w-30 oils, in which case analysis only proves that an oil close to a 5w-30 in grade will provide wear protection similar to a 5w-30 -- no great revelation there. Your point about a 5w-30 thinning out to a 20 weight is a valid point, but it again only reinforces my point that you would expect to see many 5w-20s showing wear numbers similar to your average 5w-30. My point is, they both pale in comparison to what a thicker, European-style oil would provide over the long run.

And my standard argument -- which I'll trot out again, since no one has yet addressed it satisfactorily -- is why do European cars suddenly need nice, standard, American 5w-30 when they cross the ocean? If 5w-30 provides all the protection those engines need, why do those same manufacturers require 40, 50, or even 60 wt. oil in those same engines in Europe? Because they care more about engine life than fuel efficiency in Europe, plain and simple.

If it seems like I'm angry, it isn't directed at you Patman! You know the target of my indignation ...

 

[kev99sl]

quote:

---

Originally posted by Patman:
Perhaps US automakers might be stupid in some ways (such as GM killing the f-body, a mistake I'll NEVER forgive!!) but Honda isn't stupid. They have a reputation for reliability that they don't want to lose. People buy Hondas based on word of mouth from other Honda owners. That's why I bought the 2000 Civic my wife drives. I knew lots of Honda owners who had good luck, so I took the chance.

---

Yes, but have you considered that perhaps they too have finally been bullied into line by US fuel efficiency requirements? Besides which, my once unshakable faith in Honda subsided more than a little when I figured out that their North American oil filters are now exclusively simple, crappy Frams!

 

[Patman]

You do raise some excellent points Kevin!

The tricky thing is, there is no easy answer to all of this, as it'll be many years before we start seeing the 5w20 cars hit higher mileage.

I'm just saying it's probably not going to be as bad as everyone thinks. If Mobil 1 5w30 can give long engine life, when many times it ends up at 9.3cst at 100c, then there is no reason why a 5w20 (or 0w20) can't also provide long engine life when it starts out (and most likely stays at) 9.0cst at 100c. The difference is too close to call. Even the difference between 8.5cst and 9.5cst is pretty close really.

 

[sprintman]

kev99sl
Are 'tis truly one of the wonders of the universe that engines being shipped to the States instantly require a lower viscosity oil. Even Einstein would have trouble explaining that.

 

[MavRick]

quote:

---

Originally posted by Patman:
Perhaps US automakers might be stupid in some ways ... but Honda isn't stupid. They have a reputation for reliability that they don't want to lose. People buy Hondas based on word of mouth from other Honda owners. That's why I bought the 2000 Civic my wife drives. I knew lots of Honda owners who had good luck, so I took the chance.

---

Patman, first your assumption Honda isn't stupid is very subjective and therefore has no basis in fact. I could say they are stupid because they used to be number one Japanese auto maker, now Toyota is.

Honda does have a reputation for reliable engines, but this has little to do with oil in my opinion. Oil can't make up for a bad engine manufacturing quality, but a well built engine can make just about any oil look good (like honda's).

I believe the oil we select is only changing the life of the engine by a percentage up or down. I think many, like myself, believe 5w20 is making it last a bit less than a good 5w30 oil. Maybe the 0w40 from Mobil 1 will make an engine last even longer but doesn't make the EPA happy because of fuel economy reasons. If so shouldn't we select that if longevity is our goal?

Even still, under normal conditions it isn't even a very interesting comparison because they both will protect adequately. What I want to know is if I get in a situation where I'm going up a 7% grade in 110 degree temperatures, which oil will provide better protection? Or simply driving around Phoenix Arizona in 117 degree temps which one would work. Since Ford and Honda don't specify different oils for different conditions I think we all have reason to be skeptical of their "intellegence" don't we?