Why The Dislike For 20W-50?

[Red91]

I don't want to argue. I'd like us all to get along honestly. When I first came here, I got myself into some arguments and really didn't have a leg to stand on. In fact, I may have been snide with you regarding how to calculate final viscosity of an oil mix. It was petty and stupid of me to act that way. I suppose I'm a middle of the road person when it comes to oil. I'm not a synthetic user or supporter, but I also don't bash it. Although I will state that I think it's overkill in certain situations. I use conventional myself, and recommend it if asked. I do think now that we all read a little too much into our obsession(nature of the beast?). For example, I cannot find a reason why SL rated 10W-30 couldn't be used in a 2014 Camry, nor why SN rated 0W-20 couldn't be used in a '71 Ford F100 with a 351 V8. Both decisions may not be optimal or socially popular, but little to nothing would change about the vehicles or their respective engines. I can't join one camp or the other(thick vs. thin), as both have good factual points and folklore walking hand in hand. The point of this thread is to hear why some dislike the grade, and completely disregard it as an option. As for me, I'll probably run 10W-40 and 20W-50 of various API service indices until I become bored with it, then probably start using 5W-20's for awhile....

 

[SilverSnake]

Originally Posted By: FastLane
My airplane likes 20W50. Not sure why you would use it in a car engine.


+1 My HD loves 20W-50 Syn 3 in the engine, transmission, and primary chain case. Great oil for that application. Can't think of a car I would use it in.

 

[zray]

I haven't used 20w-50 in a car, but the since the old Triumph vertical twin motorcycles loved it in the 1960's, and still do.

But I do use Mobil 1 15w-50 in vintage cars, and it works much better than the 10w-30 that Ford recommended for them when they were new. Of course there were no synthetic oils back then. In an extreme duty environment, such as endurance racing where the engine is at the red line for extended periods of time, the Mobil 1 15w-50 has proven, to the vintage racing community, to be a vital component for the cars that can actually finish a long distance race, and be at the front of the pack too. I, and others, have been using it for so long that no one can remember when a lubrication related failure has happened. I acknowledge that there be a small HP loss vs. a thinner oil. But that seems a small price to pay for reliability in this instance. And Mobil 1 recommends it for all vintage flat tappet engines (non roller cam).

Z.

 

[riggaz]

It's not unpopular, It's an oil, it has an application.

What is popular is not always what is correct for the application, for example

If you were to ask anyone over here in the British Isles what oil is needed for a car that is pre 1990 they would almost all say "you'll need 20w50 in that", they will not
say "have a look in the owners manual for the recommended viscosity".

The trouble is what is popular is usually based on what is well known and available to people who do not understand the importance of getting the application right.

Many cars like E-types, Healeys, Austins etc required SAE30 or 10w-30 but because 20w-50 was widely available and marketed well (and egged on by the counter staff that also had no idea about oil either and more importantly only stocked 20w-50) that's what they got in them rather than the owner sourcing what was recommended in the manual.

In hot countries it will still be widely used as it will suit engines operating in that climate but in moderate or cold climates (in the same engines)it will not be right for the application so will not be widely used.

Source the recommended specification and viscosity for your ambient temperature/climate in the owners manual, simple.

 

[Clevy]

Originally Posted By: Red91
I don't want to argue. I'd like us all to get along honestly. When I first came here, I got myself into some arguments and really didn't have a leg to stand on. In fact, I may have been snide with you regarding how to calculate final viscosity of an oil mix. It was petty and stupid of me to act that way. I suppose I'm a middle of the road person when it comes to oil. I'm not a synthetic user or supporter, but I also don't bash it. Although I will state that I think it's overkill in certain situations. I use conventional myself, and recommend it if asked. I do think now that we all read a little too much into our obsession(nature of the beast?). For example, I cannot find a reason why SL rated 10W-30 couldn't be used in a 2014 Camry, nor why SN rated 0W-20 couldn't be used in a '71 Ford F100 with a 351 V8. Both decisions may not be optimal or socially popular, but little to nothing would change about the vehicles or their respective engines. I can't join one camp or the other(thick vs. thin), as both have good factual points and folklore walking hand in hand. The point of this thread is to hear why some dislike the grade, and completely disregard it as an option. As for me, I'll probably run 10W-40 and 20W-50 of various API service indices until I become bored with it, then probably start using 5W-20's for awhile....



You can't use an SL spec oil in a 2014 Camry because of potential emission equipment fouling,thus shortening it's life.
Sm and SN reduced phos to combat the non existent issue of shortened emission equipment life.
Just sayin.

 

[Geonerd]

Originally Posted By: Shannow
Originally Posted By: MalfunctionProne
4. Oil doesn't make engine parts "ride on a film of oil" or "cushion" an engine with thick oil.


Interested in exploring this further...how does hydrodynamics work ?

Streibeck curves ?

Sommerfeld number ?


Fairy Dust, and lots of advertizing dollars!

Some of the 'Thinnies' seem to think that magic base stocks or 'New and Improved!" AW additives can somehow substitute for raw HTHS. Nonsense. At the end of the day, HTHS is indeed responsible for the protective 'film of oil.'

(I'll go along with them up to a point. Some base oils can achieve a higher HTHS with lower cSt values. But this in no way justifies some of the nonsense you see around here.)

 

[Shannow]

Originally Posted By: Geonerd
(I'll go along with them up to a point. Some base oils can achieve a higher HTHS with lower cSt values. But this in no way justifies some of the nonsense you see around here.)


Agreed...it's what the new basestocks and additives do, make better oils with better HTHS for their KV numbers.

Problem is, when you are battling a storm of pixie dust and unicorn tears, they just label you a "hater" to avoid having to argue on grounds of science and fact.

 

[Lex94]

Originally Posted By: Geonerd
Originally Posted By: Shannow
Originally Posted By: MalfunctionProne
4. Oil doesn't make engine parts "ride on a film of oil" or "cushion" an engine with thick oil.


Interested in exploring this further...how does hydrodynamics work ?

Streibeck curves ?

Sommerfeld number ?


Fairy Dust, and lots of advertizing dollars!

Some of the 'Thinnies' seem to think that magic base stocks or 'New and Improved!" AW additives can somehow substitute for raw HTHS. Nonsense. At the end of the day, HTHS is indeed responsible for the protective 'film of oil.'

(I'll go along with them up to a point. Some base oils can achieve a higher HTHS with lower cSt values. But this in no way justifies some of the nonsense you see around here.)


Yup...And you have to concern yourself with shear stability as well.
A non-Resource Conserving conventional 10w30 like Pennzoil High Mileage should be shear stable thru the entire OCI and provide adequate HTHS in most applications. How many engines running Xw-20 start sounding like a blender of BBs after 100K miles? I would use 20w50 before a conventional 10w40.

Thinnies and Thickies? - Don't get that started

 

[Lex94]

The earth revolves around the sun??? - Hater!!!

When I hear "Hater"...I hear "Blasphemy"
The word "Hater" is just friggin Juvenile.

 

[kschachn]

Errm, I don't know, do you?

In my case it is zero, but I only have two (the Toyotas) that run such an oil so I don't know about everyone else.

Originally Posted By: Lex94
Yup...And you have to concern yourself with shear stability as well.
A non-Resource Conserving conventional 10w30 like Pennzoil High Mileage should be shear stable thru the entire OCI and provide adequate HTHS in most applications. How many engines running Xw-20 start sounding like a blender of BBs after 100K miles? I would use 20w50 before a conventional 10w40.

 

[Lex94]

Errm, Nope.

 

[CATERHAM]

Originally Posted By: Geonerd
Originally Posted By: Shannow
Originally Posted By: MalfunctionProne
4. Oil doesn't make engine parts "ride on a film of oil" or "cushion" an engine with thick oil.


Interested in exploring this further...how does hydrodynamics work ?

Streibeck curves ?

Sommerfeld number ?


Fairy Dust, and lots of advertizing dollars!

Some of the 'Thinnies' seem to think that magic base stocks or 'New and Improved!" AW additives can somehow substitute for raw HTHS. Nonsense. At the end of the day, HTHS is indeed responsible for the protective 'film of oil.'

(I'll go along with them up to a point. Some base oils can achieve a higher HTHS with lower cSt values. But this in no way justifies some of the nonsense you see around here.)

The reason the 20W-50 grade is obsolete is not because it is a 50 grade oil with a nominal 4.8+cP HTHSV, but rather it's poor cold start performace, being a 20W oil with a very low typical 130 VI.
The truth is, if you want to maximize the HTHSV of an oil for a given operational viscosity at normal operating temp's that is only possible by using the highest VI 0W and 5W oils.
As a result the most advanced race oils are 0W with a high VI.

 

[Doug Hillary]

Hi,
Red91 - I'll just add a little more - as I've told this story before

Duckhams introduced the 20W-50 viscosity as BMC (Austin-Morris) started to introduce the original Mini - this was in 1959. The reason was pure and simple, the combined engine-transmission permanently sheared the normal lubricant viscosities specified for the "A" series engines (SAE20W-20, SAE30 and SAE30-40)

As OCIs were then around 1k miles then you can appreciate that the permanent shear factor was very real - it led to excessive wear and leaks at every point! The 20W-50 also caused problems of its own with oil pumps when used in cold ambient temps. But that's another story!!

Castrol quickly introduced a 20W-50 viscosity lubricant too (but did not replace their XXL 30-40), and as a later Poster (A Brit) indicated it (20W-50) became the lubricant of "default"

One of my early "Engineering" tasks was to refine the first CKD export package Mini - this started in Dec 1959 - 55 years ago. But I won't go into that either

The 20W-50 viscosity was rapidly used as a "quick fix" (leaks, oil consumption etc.) by all and sundry - Manufacturers, repairers and end users alike

Using the lowest permissible viscosity OEM conforming lubricant for the application should surely be the bottom line with modern engines at least

Some SAE50 lubricants such as Mobil 1 5W-50 are truly great lubricants - in the case of M1 5W-50 it has a great track record and many OEM Approvals

 

[aa1986]

Hi Doug,

You have such a long history in the business, back to a point where oils were, without wanting to sound too unkind and in the context of the performance we get today, quite poor.

In that time, would you say it has been a process of small incremental improvements or are there a few innovations that were real game changers?

If the latter, can you just tell us what they were?

Thanks!

 

[Doug Hillary]

Hi,
aa1986 - Just a few pointers without high jacking the Thread;

Firstly, some changes will always be incremental taking into account the end user marketplace.
Secondly, some changes were quite significant and IMO were driven by the OEM's technological developments

1 - The advent and the introduction of specific synthetic lubricants (1930s>>)

2 - OEMs testing their lubricant requirements in-house - 1950-1960s (CAT, DB etc.)
For instance DB, VW and Porsche specified HD lubricants for many years due to the substandard performance PCMOs of the era

3 - The introduction of multigrades, 10W-30 and 20W-50 viscosities in particular

4 - The OEMs "waking up" the API to significant engine developments in the late 1970s

5 - The formation of ACEA and their HTHS requirements (see 2 above)

6 - SL and CG4 generally were significant upgrades

I've found over time and even today that many engine related issues can be traced back to using a non-specified viscosity or a non OEM compliant lubricant. This is especially so with Diesel engines

At a meeting in Japan (1982) with an engine Manufacturer's Engineers I was amazed that they did not endorse a synthetic. On taking this further it became apparent that this was largely due to the final destinations of many of their products - Third World Countries etc.. They were really designed to operate on the lowest API category available. Still today many Japanese engines are very tolerant of lower API category lubricants

There are many other significant factors too but I've found over several decades that some Lubricant Manufacturers always seem to get the cleanliness and viscosity retention aspects correct

This first became really apparent to me in the last 1950s and 1960s and especially with HDEOs and diesel engine operating in very severe applications. That is one reason why I've used HDEOs in my BMWs, Porsches and Benz vehicles I've owned since the 1970s

I hope this is of interest and not too boring....

 

[aa1986]

That's awesome Doug.

I had read your mentions of some of these factors in other posts but it's invaluable to have an overall view since piecing together such a large and complex topic is difficult.

In particular, I hadn't realized that SL and CG4 were significant (given the disparity between relative performance for API vs ACEA as per Lubrizol), and also now have an explanation for why Japanese engines are generally so forgiving in their requirements.

Thanks once again!

 

[Red91]

I decided to go with Quaker State Defy 10W-40 and top off with the green bottle 20W-50.

 

[ron17571]

I don't have a problem with it. I guess getting better MPG is about the only advantage to thinner oil.
I guess living in Phoenix most of my life.Thicker oil seemed like a good idea.
I have mellowed out to 10-40.

 

[CATERHAM]

Originally Posted By: ron17571
I don't have a problem with it. I guess getting better MPG is about the only advantage to thinner oil.

Better fuel economy may be the least important advantage of thinner oils. The main advantages are less engine wear particularly on start-up and (my favorite) more power and engine responsiveness.
The key is knowing how thick an oil you need at maximum oil temp's and using nothing heavier as per the lubrication tenent "as thin as possible, as thick as necessary".

One problem most don't realize with running unnecessarily heavy oils is the huge penalty you have to pay to get just modestly greater high temperature viscosity.
Using the 20W-50 example vs say a 5W-30 syn', yes it has a 50% higher HTHSV but to get that the oil will be over 600% heavier at 32F. And if you compare the 20W-50 to a OEM high VI 0W-20, it's HTHSV is 80% higher but the price you pay is being 1400% heavier at 32F.

For the OP. If you feel the need to run a heavier than spec' 5W-30 grade oil to reduce oil consumption (you didn't mention how bad it was btw) M1 0W-40 would be my suggestion since it's relatively cheap (in the States) and you're getting the maximum hot viscosity for the minimum increase cold start viscosity.

 

[Red91]

It's not terrible for a high mileage vehicle, about 1 1/2 quarts in 1,500-1,800 miles depending on driving habits. I prefer Defy, personally.