I am tired of everybody saying 20 wt oils exist only for gas mileage

unDummy · Apr 23, 2005

So when and where did Ford/Honda make the announcement that "lower life expectancy is caused by 20wts"??

A simple solution to higher viscosity oils is oil temp control. This has been mentioned before. Doesn't 20wt keep cooler and hence at a similar viscosity to a thicker oil. Thinner oil leads to more oil flow which leads to.......The oil pressure regular dumps oil later with a thinner oil. More flow when its needed even if PSI is lower. More oil as a coolant and lube where/when its needed.

When Ford came out with the 20wt, its testing required the use of higher quality basestocks. This is one reason why the 5w20 was a success.
What would you rather have, a STOUT 20wt or a wimpy quickeelube 40wt? Not everyone wants to spend $6 a quart on oil.
What would a quickee lube place install if it wasn't forced to use the $1.50/quart 20wt? a $.59 30wt or 40wt! Remember to think in terms population majority.

Old Ford engine designs requiring 30wt?????? Nope, I just think that oil temp and flow control is good enough in those engines!

Can someone please post a link that mentions 20wt oils with tax tax and CAFE credits? I just can't find where oil weight is used in the CAFE MPG formula!

Concerning the rotary engine, it has a large sump per engine size, an oil cooler(s), oil thermostats, lots of oil pressure and flow.......The rotary lubrication is well enough designed that engine bearings are usually reused during rebuilds. The thicker is better has not been proven with this engine.
Anyone ever reuse engine bearings on a high mileage Ford/Chevy/Dodge rebuild????????

Silkolene's warning concerning the 0w20 is funny and inludes "under race conditions" and mentions nothing about street usage. You would think that someone building a race engine would be smart enough to include the appropriate oil pressure, volume, and cooling. I guess that there are race engine builders that suck. There's only one winner in a race!

Is thicker oil a bandaid for bad engine design, low quality manufacturing, and poor engineering?
Thats the vibe I'm getting from this thread.
I also think that switching to a not so popular weight is the easiest way for Ford/Honda to spec a quality lube without forcing dealer only oil/ATF like some VW's/Audi's/ZF and AW trannies!

Gotten run and add some 5w40 oil into my Nissan's 155hp ~3.5 quart(joke of a sump capacity+thimble sized oil filter), steering wheel & shifter shaking(low idle+poor engine balance), valvetrain clattering(engineering i$$ue), radiator fans running all the time(high head temp--clean emissions), 2.4L intake manifold gasket & rockercover seal eating.......

Then I'll check(even though it doesn't burn a drop) the 5w20 oil in the 160hp balanced shafted smooth quiet ~4.5 quart sump Mazda 2.3L, an engine design with some boringly excellent UOAs.

the_oil_dealer · Apr 23, 2005

so is there a relation between thinner oils and revised oil pumps in late models? how would modifying the pressure regulator's release pressure and rate benefit the use of lower viscosities?

mechtech · Apr 23, 2005

One more bullet into the fray:
Ford specs 5-20 for their widespread 2.0 liter Zetec engine, but for the limited high HP version, 5-30 is required.
The internal parts are interchangeable, and the clearances are the same.

Gary Allan · Apr 23, 2005

quote:

so is there a relation between thinner oils and revised oil pumps in late models? how would modifying the pressure regulator's release pressure and rate benefit the use of lower viscosities?

The volume of the pump must be modified if the min pressure at a given volume is below that which is required to maintain the appropriate film thickness in the potential service duty of the engine. Deeper vanes ..wider, longer, or deeper gears/rotors.

This issue isn't that one dimensional. There were very few instances of any failures with the original 5w-20 M1. That should lead many to believe that the use of this weight is within the requirements of most engines in most services. Another point, as I tried to example in a comical manner, is that these aren't radically different in viscosity from 30 weights ..that, merely because they have a "10" weight difference in designation on the label, are regarded as just fine. We, and GM, have no problem using and spec'ing a 5w-30 for a service interval that surely, due to VII, ends up as a 20 weight anyway ...but using a 20 weight over the same duration ..and having it stay a 20 weight is somehow beyond belief.

I'm a little curious about some of 1sttrucks assertions here. In other threads we are to believe that UOA can only be relied upon for testing the oil ...and not wear rates (or any indication of wear rate ..or at least to doubt it) ..but if a UOA shows that a 20 weight stays a 20 weight (actually virtually the same exact weight) ..shows limited impact of the service duty..no or minimal loss of visc, ox/nit/tbn/insloubles/etc........

..is that now invalid too??

AEHaas · Apr 23, 2005

Two things determine the oil viscosity needed. One is the bearing clearance. If there is more clearance then a thinner oil will need to be run through it faster or a thicker oil can be used that flows slower. Tighter clearances will allow for a thinner oil to be used. Or a thin oil that is kept slightly cooler will be thick enough to be used in an engine with greater clearances.

The other thing is the height of the asperities. This is the main technological advancement that allows for thinner oils. If surfaces were perfectly smooth then a 0 wt or thinner oil could be used easily. Older engines have greater asperity irregularties and heights.

It is the asperities that touch and in fact weld together when the oil film thickness is too small. With further rotation of the journal the weld breaks sending metal particles into the oil. My understanding is the the Zn does in fact combine with the engine metals when needed to prevent the welding of asperities that touch. It may be that after time these surfaces smooth somewhat from the adsorption of these HP, ant-wear additive. It would be interesting to see electron micrographs of these surfaces over time.

Oil cannot be completely squeezed out from a bearing. It can only be thinned. Thicker oils would be useful when surfaces are not parallel. In this case a wedge shaped bearing space will run into difficulties of several types.

It is the advancement of manufacturing technologies that is allowing for the use of thinner oils and I predict they will continue to thin.

aehaas

427Z06 · Apr 23, 2005

quote:

Originally posted by AEHaas:
Two things determine the oil viscosity needed.

I believe there are some secondary considerations that also need to be considered per engine design.
As examples, someone mentioned that certain BMWs engines will loose their prime with "thin" oils. A SBC/BBC may actually pump the sump to an unacceptable lower level under certain conditions. Cam bearings made of aluminum journals in a OHC engine may need quicker or additional flow. VVT designs that use oil as pseudo hydraulic fluid. Etc, etc.

JohnBrowning · Apr 24, 2005

Thorn if you look at Redline you see that they have a good HTHS!! The higher the HTHS up to about 4 the better. Generaly an HTHS of 2.6 is consider the absolute minimum any engine can survive on. The closer you get to 3.6 the better as this seems to be the best comprimise for the N.American market in terms of being able to find it in a fuel efficent oil and a lower SAE viscosity. Once you pass 3.6 the oils available with the enerby conserving markeing and GF-4 status starts to drop off. You usualy have to go thicker then a 30Wt. to get much past an HTHS of 3.6 with a few exceptions!

Now when you are looking at the Redline you also see that it's viscosity rateing is 145 compared to the Amsoils lower HTHS of 2.9 and higher viscosity index. THat tells you that Redline is probably not useing any viscosity improvers at all!

I would not go near any oil with a HTHS of 2.6 especily if it has a timeing chain and non-rollerized top end!

Nomex underware? Check! Aspestos mittens? Check! Continious spray of water? Check!Coragated tin? Check! I think that it is going to become clear in the long run that any bearing wear we see with low HTHS oils especialy one with an HTHS of 2.6 is going to be from the rod bearings instead of main bearings. I think most of the iron we are going to see in UOA is going to be from timeing chain wear instead of from the rings. Just conjecture on my part as I have no proof of this!!

Thorn · Apr 24, 2005

I was considering Redline because of its relatively high HTHS for a 20 wt. However, now I'm wondering whether the Redline may react with the "soft" metallurgy of the Honda bearings that was mentioned in another post describing Honda's engineering of new engines in the '90s.

Could this exacerbate the high Pb readings that some people mention regarding Redline?

427Z06 · Apr 24, 2005

quote:

Originally posted by Thorn:
I was considering Redline because of its relatively high HTHS for a 20 wt. However, now I'm wondering whether the Redline may react with the "soft" metallurgy of the Honda bearings that was mentioned in another post describing Honda's engineering of new engines in the '90s.

Could this exacerbate the high Pb readings that some people mention regarding Redline?

Thorn · Apr 25, 2005

I'll be the first to admit that I don't know anything about motor oil. I'm just a Honda owner that's trying to figure out what to do about the 5w20 question.

As is usually the case, a little bit of knowledge can be dangerous. Based on information from separate posts that I read here, I merely became curious as to whether there is any connection between some things that have been written about Redline's chemistry and things written here about Honda's bearing materials.

The UOAs that you pointed to are generally good, and in cases where there is even a slight cause for concern, it is usually completely explained by the circumstances, such as racing with the tested oil.

But there are a few comments scattered in these UOAs that may be at least worth considering. I took only one negative comment from any one UOA, so they don't all refer to one bad sample.

"not sure I would agree wear metals are trending down. Si the same but copper and lead are up over a year ago. Good report, statistically insignificant in the differences but some up some down would be my interpretation."

"great numbers, finally get to see some low lead numbers in a Honda with Redline. might dispell some of those rumours out there about RL and Honda bearings."

"Redline consistently shows high lead readings in Honda/Acura engines. I believe it has to do with the specific type of metallurgy used in their main/rod bearings...."

"Wear numbers all look better with the Mobil 1. The only number that was worse was nitration. -Joe"

And finally, one more from Redline:

"Oil analyses is primarily used by fleet operators to help determine change intervals and to watch for developing trends. As such it isn't really designed to compare wear between oils. We find with our oil when it is initially installed the reaction of the additives shows higher wear metals, with further use these numbers will tend to decrease, this is just due to an initial reaction and protection of the surface. I wouldn't be concerned with slightly higher test results between one product an another. These levels are very-very small, the accuracy is generally +-20%, determining a better product as a result is problematic.

Regards, Dave
Red Line Oil"

The positive comments outweigh the negatives by a ton. However, some of the negative comments were made by regular contributors that seem to know what they're talking about.

I'm just curious.

427Z06 · Apr 26, 2005

Thorn, my comment wasn't directed at you. It was directed at the person that started the rumor by not qualifying his opinion carefully enough.

quote:

Originally posted by Thorn:
However, some of the negative comments were made by regular contributors that seem to know what they're talking about.

The operative word here is "seem".

This is after all the internet. I don't care what someone claims their credentials are, I'll ask for corroborating evidence more times than not.

(Isn't that right, Terry?)

buster · Apr 26, 2005

I like Redline for hard driving/racing conditions. I prefer M1/Amsoil for longer drains.

427Z06 · Apr 26, 2005

See here Thorn. Here's a perfect example of what I mean.

quote:

Originally posted by buster:
I like Redline for hard driving/racing conditions. I prefer M1/Amsoil for longer drains.

(Just funnin' with you buster.)

TooSlick · Apr 26, 2005

As a practical matter, there is very little difference between an API/SM rated, 5w-20 and 5w-30 in terms of high temp, high shear viscosity. In addition, the small amount of higher quality Group III base stock in the SAE 5w-20's tends to make them more shear stable.

So in reality, it would be correct to say the 5w-20's are only slightly thinner and offer a small benefit in terms of performance, cold weather behavior and fuel efficiency.

If you don't feel comfortable using an SAE 5w-20, you have to go up to at least an Xw-30 thick enough to meet the ACEA 'A3/B4" specs to significantly effect oil pressure and oil film thickness. Running a typical, API/SM rated, 5w-30 or 10w-30 isn't going to do ANYTHING for you....
Modern engines just aren't that sensitive to small variations in viscosity anyway. This is why the Mobil 5w-30 and 10w-30 work just fine in VW 502.00 applications - even though they are about 10%-15% too thin to meet the min HT/HS spec of 3.5 Cp @ 150C.

427Z06 · Apr 26, 2005

quote:

Originally posted by TooSlick:
Modern engines just aren't that sensitive to small variations in viscosity anyway. This is why the Mobil 5w-30 and 10w-30 work just fine in VW 502.00 applications - even though they are about 10%-15% too thin to meet the min HT/HS spec of 3.5 Cp @ 150C.

I guess the same could be said for people who obsess over the HT/HS spec of 3.5 Cp @ 150C when their engine manufacturer calls for 3.0-3.2 @150C SAE 5-10w30 oil. M1 0w40 and GC users in LSx fans you listening?

1sttruck · Apr 26, 2005

Gary Allan said: "I'm a little curious about some of 1sttrucks assertions here. In other threads we are to believe that UOA can only be relied upon for testing the oil ...and not wear rates (or any indication of wear rate ..or at least to doubt it) ..but if a UOA shows that a 20 weight stays a 20 weight (actually virtually the same exact weight) ..shows limited impact of the service duty..no or minimal loss of visc, ox/nit/tbn/insloubles/etc..........is that now invalid too?? "

As I've stated previously, 5w20 will work fine for the vast majority of vehicles that 'need' it in the US, but unlike what 5w20 advocates refuse to acknowledge, it doesn't offer the same protection a heavier oil. Looking at some more specifics....

5W20 does not have 'essentially the same viscosity' or 'essentially the same wear protection' as 5w30, as Ford acknowledged a large enough difference to exclude some of the most popular vehicles in their fleet from using it. If there is no difference then why did Ford exclude the vehicles from using it ? What property of 5w20 prevented Ford from recommending it ?

Ford also recommends 5w30 in either higher performance versions of the some vehicles that use 5w20, or recommends 5w30 outside of the US when it's filled with 5w20 at the factory, because Ford, like the rest of the world, acknowledges that a heavier oil will provide better protection than a lighter oil, and in some cases that protection is needed. At any higher operating temperature 5w20 will have a lower viscosity than a 5w30, it will have a thinner film, and consequently will suffer more with a given population of particles and surface roughness than a 5w30.

5w20 isn't one oil, it's a 'weight' for a large number of oils that will be used. Some makers know enough to put caution labels on their bottles stating that it should only be used in vehicles approved for it, as there has been too much hype about it being better than 5w30. It's ironic that with either a light dino or synthetic being promoted for 'being green' it's not unusual for some people to experience a noticeable increase in oil consumption, which will produce more air pollution. One can only imagine how much more oil would be burned in the population of older cars, some running 40 weight to try to control oil consumption.

1sttruck · Apr 26, 2005

A couple of more items...

5w30 seems to be used in some vehicles with turbos, but 5w20 doesn't seem to be used much in that application. I don't know what a good hp rating is for cars, bikes are at 180 hp per liter in the 1 liter sizes, but let's use 100 hp per hp a cutoff; what vehicles with that kind of output are using 5w20 ?

'One must use 5w20 because of the tight clearances, otherwise the engine damage will occur....' seems to be another another false statement, as some police agencies are using not only 5w30, but 15w40.

427Z06 · Apr 26, 2005

quote:

Originally posted by 1sttruck:
5w20 isn't one oil, it's a 'weight' for a large number of oils that will be used.

Actually it is called a SAE Viscosity Grade, and in this case, it's a MultiGrade.

quote:

Originally posted by 1sttruck:
Some makers know enough to put caution labels on their bottles stating that it should only be used in vehicles approved for it, as there has been too much hype about it being better than 5w30.

When the first 5w20 oil was made to Ford specifications, it had to pass more stringent tests than the average 5w30 dino of the time. So if you don't strictly define "better" as thicker, it was.

Now that doesn't mean I would put in a VW/Audi engine and run it on the Autobahn at WOT for an extended period of time. Many other engines wouldn't do well with it either. But running your engine spec-ed for it at WOT for extended periods of time shouldn't be a problem since the manufacturer tested it under this condition.

TooSlick · Apr 26, 2005

Domestic and Japanese auto manufacturers don't specify a minimum HT/HS viscosity for their various engines. However from the standpoint of an experienced propulsion/materials engineer, I'd like to see them do so. Technically it's the correct approach ....

There are a number of domestic engines that exhibit optimum wear and NVH characteristics with the xw-30, "A3/B4" formulations. Paradoxically these tend to be the lower rpm, GM and DC pushrod designs....The OHC and DOHC Ford motors run better with the thinner 5w-20/0w-30/5w-30 grades - at least that's the feedback I get from end users.

The high rpm Japanese motors also do just fine on the thinner 5w-30/10w-30 and even 0w-20/5w-20 formulations.

Tooslick

JohnnyO · Apr 26, 2005

I think the 20 weights are used largely for better gas mileage, on the other hand they are perfectly fine when used in an engine designed for them. I got good UOA's from my wife's 3.0 Taurus with both Motorcraft 5w-20 and M1 0w-20, wear metals and everything else looked great, so I'm okay with it.

I am tired of everybody saying 20 wt oils exist only for gas mileage

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