Anyone still using 20w50?

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My father had a Buick with a 3800 series 2. Like so many of those it hydro locked due to a faulty egr design in the intake manifold at less than 50k. Wiped the bearings out. It had almost no oil pressure with 30wt oil at temp and the low pressure light would flicker at idle. With 20w50 the light never came on and pressure was within spec.

He ran the car like that for another 250,000 miles. No issues and no oil consumption. Engine ran like new when the car was sold… With full disclosure. Right tool for the job in this case.
 
Wow, Ive had my experience with 20w50 in the teens and it wiped out my oil pump and rod/main bearing on my dodge Aries kcar. I remember older peoplease using it then but nowadays seems like they dont. Just curious I'd anyone still did.
 
Originally Posted by Doublehaul
My father had a Buick with a 3800 series 2. Like so many of those it hydro locked due to a faulty egr design in the intake manifold at less than 50k. Wiped the bearings out. It had almost no oil pressure with 30wt oil at temp and the low pressure light would flicker at idle. With 20w50 the light never came on and pressure was within spec.

He ran the car like that for another 250,000 miles. No issues and no oil consumption. Engine ran like new when the car was sold… With full disclosure. Right tool for the job in this case.


I swear those 3800s are indestructible!!
 
I use Brad Penn 20w50 oil in my street/strip 493 Mopar. Has loose bearing clearances and runs about 220F oil temp.
It has a HTHS of 6.2. Works good for a 750hp engine.
 
I use 20/50 brad penn in my drag engines(chevy) and upon tear downs
switching from a brand like valvoline or castrol to a real race oil defiantly showed me
a better looking bearing
 
Hi,
I ran 20W50 in my 1L Morris Minor Traveler in the 80's. I have owned 70's cars since then & never put 20W50 in them.

I would say there about five different types of 20W50. (List could easily be expanded to 5+) Price doesn't really come into the equation but I'm sure profit does.
• Oil blends form the 60's. Group 1 oils. 5H1T3
• Grp1 or Grp 2 "Classic car oils" with added ZDDP in advertising. Extra ZDDP was not required then & less so now, as no Pb in pump fuel. 5H1T3
• Modern formulated mineral oils that are Grp 3 or higher.
• Fully synthetic oils Grp4 & above.
• Boutique oils. Boutique use. Boutique price. Poor flow rate at ambient starting temperatures is not an issue if you use these I guess.

I know nothing about air-cooled engines.
If your engine is burning oil or leaking it go Green & fix the problem not mask it with thicker oil.
If your engine has low oil pressure & you believe that moving to 20W50 will magically increase the flow/oil pressure; Dream on. Fix the problem as 20W50 will not make things better.
IF BMW is specifying 20W50 for some of their engines I would suspect engine designed issues & not recommendations for using 20W50 in the 21st century.

My engine design is from the 60's & 20W50 oil of that era was one of the handfuls of viscosities recommended for my engine. 20W50 API SE being one of them.
I do not recommend 20W50 in a 20th-century car engine. Far better viscosities are available. I run M1 0W40 all year on my daily Spitfire Six.
Cheers,
Iain.
 
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Originally Posted by SpitFire6
Hi,
I ran 20W50 in my 1L Morris Minor Traveler in the 80's. I have owned 70's cars since then & never put 20W50 in them.

I would say there about five different types of 20W50. (List could easily be expanded to 5+) Price doesn't really come into the equation but I'm sure profit does.
• Oil blends form the 60's. Group 1 oils. 5H1T3
• Grp1 or Grp 2 "Classic car oils" with added ZDDP in advertising. Extra ZDDP was not required then & less so now, as no Pb in pump fuel. 5H1T3
• Modern formulated mineral oils that are Grp 3 or higher.
• Fully synthetic oils Grp4 & above.
• Boutique oils. Boutique use. Boutique price. Poor flow rate at ambient starting temperatures is not an issue if you use these I guess.

I know nothing about air-cooled engines.
If your engine is burning oil or leaking it go Green & fix the problem not mask it with thicker oil.
If your engine has low oil pressure & you believe that moving to 20W50 will magically increase the flow/oil pressure; Dream on. Fix the problem as 20W50 will not make things better.
IF BMW is specifying 20W50 for some of their engines I would suspect engine designed issues & not recommendations for using 20W50 in the 21st century.

My engine design is from the 60's & 20W50 oil of that era was one of the handfuls of viscosities recommended for my engine. 20W50 API SE being one of them.
I do not recommend 20W50 in a 20th-century car engine. Far better viscosities are available. I run M1 0W40 all year on my daily Spitfire Six.
Cheers,
Iain.


Your argument about poor flow rate at ambient starting temperatures is just not true, in above freezing temps, even Group 1 20W-50 flows just fine, go read some of Shannow's posts.

Modern 20W-50 oils are a more than reasonable and good oil choice for many European pre-80s classic cars.
My Capri sure likes 20W-50.
It's noisy and uses oil on synthetics, perfect on 20W-50, good oil pressure, no noise, no oil consumption or leaking.

The high HTHS is certainly positive for older engines and their bearing designs that necessitate it.
 
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You can get quality modern thick oils in Australia

Penrite 10-Tenths Racing 20W-60
It's 100% PAO and Ester
TBN = 9.8
KV100 = 23.7 cSt
Boron = 630 ppm
Zinc = 1680 ppm
And it's rated API SN

Good for the street and good for the track. But we do like our oils thick and full of zinc.

BTW 20W-50 / 20W-60 is a fine winter grade for most of Australia, as it's a bit warm here, and it's my preferred outback grade for an older car.
 
My engine also is an design from the late 60s that just underwent very minor changes throughout the time it was built.

It does consume very few oil, but the engine is quite noisy due to its design. The engine itself is in great condition and I have no oil-pressure issues at all. A thicker oil just quiets it down really well.

Using Mobil 1 0W-40 in an older engine has some up- and downsides that need to be considered and based on the specific case it must not necessarily be a great idea.
For instance:


1) Seals: The thin oil is much more likely to leak out of the weaker, older seals. If your engine was re-sealed you can ignore this point. If it was not, don't bother using 0W-40 as there are no notable advantages that would be worth renewing some leaking seals.

2) Viscosity: Older, sometimes carbureted engines tend to dilute the oil with more gasoline than newer engines. They run very rich amongst cold start and still not stoichiometric once they reached temperature.
The thin base-oil can quickly become a 0w30 with enough fuel dilution.

3) HTHS: The HTHS is not really an issue with an older car. Modern 0W-40 oils with HTHS values > 3,5 are likely more sheer resistant than the most 20W-50 oils from back in the day. That is by the way one reason why they used those thick oils, to help boost the HTHS which was generally speaking very poor for older mineral oils.
However, modern 20W-50 oils are more sheer resistant than a 0W-40 and if you are a sporty driver, why not use this advantage?


If you are scared of using a 20W-50 there are many steps in between like a 10W-40, 10W-50 or 15W-50 one can try out.
 
Originally Posted by Mitsu_Joe
My engine also is an design from the late 60s that just underwent very minor changes throughout the time it was built.

It does consume very few oil, but the engine is quite noisy due to its design. The engine itself is in great condition and I have no oil-pressure issues at all. A thicker oil just quiets it down really well.

Using Mobil 1 0W-40 in an older engine has some up- and downsides that need to be considered and based on the specific case it must not necessarily be a great idea.
For instance:


1) Seals: The thin oil is much more likely to leak out of the weaker, older seals. If your engine was re-sealed you can ignore this point. If it was not, don't bother using 0W-40 as there are no notable advantages that would be worth renewing some leaking seals.

2) Viscosity: Older, sometimes carbureted engines tend to dilute the oil with more gasoline than newer engines. They run very rich amongst cold start and still not stoichiometric once they reached temperature.
The thin base-oil can quickly become a 0w30 with enough fuel dilution.

3) HTHS: The HTHS is not really an issue with an older car. Modern 0W-40 oils with HTHS values > 3,5 are likely more sheer resistant than the most 20W-50 oils from back in the day. That is by the way one reason why they used those thick oils, to help boost the HTHS which was generally speaking very poor for older mineral oils.
However, modern 20W-50 oils are more sheer resistant than a 0W-40 and if you are a sporty driver, why not use this advantage?


If you are scared of using a 20W-50 there are many steps in between like a 10W-40, 10W-50 or 15W-50 one can try out.


+1
 
[/quote]

Your argument about poor flow rate at ambient starting temperatures is just not true, in above freezing temps, even Group 1 20W-50 flows just fine, go read some of Shannow's posts.

Modern 20W-50 oils are a more than reasonable and good oil choice for many European pre-80s classic cars.
My Capri sure likes 20W-50.
It's noisy and uses oil on synthetics, perfect on 20W-50, good oil pressure, no noise, no oil consumption or leaking.

The high HTHS is certainly positive for older engines and their bearing designs that necessitate it.

[/quote]
Hi,
20Wx is not OK in any engine from any era that is not worn out. Your engine is. So keep using it or "fix" your engine.
I do not know of "Shannows" posts so can not comment.
So you are saying that you burn oil with 20W50 group 4/5 oils but not 20W50 minerals?
"High HTHS" oils are required for old engine designs? Suggest you rebuild your engine to OEM spec & use a modern oil if you love your car. You appear to love your car.
Group 1 or 2 oils are SH1te, period. End of.
Cheers,
Iain.
 
Some modern cars spec 20W50 via fsm for reasons such as racing,extended high speed driving,and high ambient temperature operation.

Shannow is a very respected member here and probably one of the most intelligent and educated members of this forum. If memory serves me right,he's an engineer who's been involved in lubricant production. Search the forum and read some of his posts and you'll understand what FordCapriDriver is talking about.
 
Iain,


It would be nice if you provided some evidence for your blanket statements.

Like, 20W is not ok in any engine from any era that is not worn out?

Group 1 or 2 oils are SH1te, period?
 
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We sell 20w-50 at work... All day, to two types of customers:
1. The guys from South of the border that put this thick stuff in anything from 80s Toyota pickups to high mileage Hondas to newer cars that spec 5w-20.
2. Old guys with old trucks and race engines.
 
Originally Posted by Silk
And why do I have to ''fix'' my engine ? Where's that cat meme - you can't tell me what to do Karen.


+1

My engine is perfectly fine i don't need to "fix it"
 
Originally Posted by SpitFire6

Hi,
20Wx is not OK in any engine from any era that is not worn out. Your engine is. So keep using it or "fix" your engine.
I do not know of "Shannows" posts so can not comment.
So you are saying that you burn oil with 20W50 group 4/5 oils but not 20W50 minerals?
"High HTHS" oils are required for old engine designs? Suggest you rebuild your engine to OEM spec & use a modern oil if you love your car. You appear to love your car.
Group 1 or 2 oils are SH1te, period. End of.
Cheers,
Iain.




The first part is utter nonsense. Sorry, but there is no other way of putting it.
Please back your statements up by factual arguments or they do have little value.
You can not just deem something to be not suitable while ignoring the application,vehicle and the environment the vehicle is used in.

Take a viscosity calculator and play with it for a little bit. Mannol Safari 20W-50 (the cheapest dino stuff you can find over here) has a viscosity of ~ 393 Cst @ 75 degrees F.
Castrol GTX 5W-40 as a benchmark shares that same viscosity at around ~ 40 degrees Fahrenheit. Using a 5W-40 grade at that temperature will surely not result in greatly increased engine wear.

Especially on older engines that were designed to run 10W-40 or even 15W-40 oils in freezing winter temperatures when they were new.
If temperatures rarely dip below 50-60 F it is completely safe to use a 20W-50 oil if the owners manual allows it.

Just to give you a relation:
How high is the viscosity of Castrol GTX 10W-40 oil at 14 degrees fahrenheit for instance? 2556.59 Cst...

20-30 years ago, nearly all cars here ran on 10W-40. Also during winter, with temperatures going as low as -10 F.
In 2014, we sold our old car that always ran 10W-40 (built in 1996) with ~170k miles, the engine still ran perfectly and without oil consumption while the rest of the car was basically falling apart.

If you want to cross-check anything I said, look at the corresponding data-sheets and a viscosity calculator of your choice, the data is all out there...
 
Last edited:
Originally Posted by Mitsu_Joe
Originally Posted by SpitFire6

Hi,
20Wx is not OK in any engine from any era that is not worn out. Your engine is. So keep using it or "fix" your engine.
I do not know of "Shannows" posts so can not comment.
So you are saying that you burn oil with 20W50 group 4/5 oils but not 20W50 minerals?
"High HTHS" oils are required for old engine designs? Suggest you rebuild your engine to OEM spec & use a modern oil if you love your car. You appear to love your car.
Group 1 or 2 oils are SH1te, period. End of.
Cheers,
Iain.




The first part is utter nonsense. Sorry, but there is no other way of putting it.
Please back your statements up by factual arguments or they do have little value.
You can not just deem something to be not suitable while ignoring the application,vehicle and the environment the vehicle is used in.

Take a viscosity calculator and play with it for a little bit. Mannol Safari 20W-50 (the cheapest dino stuff you can find over here) has a viscosity of ~ 393 Cst @ 75 degrees F.
Castrol GTX 5W-40 as a benchmark shares that same viscosity at around ~ 40 degrees Fahrenheit. Using a 5W-40 grade at that temperature will surely not result in greatly increased engine wear.

Especially on older engines that were designed to run 10W-40 or even 15W-40 oils in freezing winter temperatures when they were new.
If temperatures rarely dip below 50-60 F it is completely safe to use a 20W-50 oil if the owners manual allows it.

Just to give you a relation:
How high is the viscosity of Castrol GTX 10W-40 oil at 14 degrees fahrenheit for instance? 2556.59 Cst...

20-30 years ago, nearly all cars here ran on 10W-40. Also during winter, with temperatures going as low as -10 F.
In 2014, we sold our old car that always ran 10W-40 (built in 1996) with ~170k miles, the engine still ran perfectly and without oil consumption while the rest of the car was basically falling apart.

If you want to cross-check anything I said, look at the corresponding data-sheets and a viscosity calculator of your choice, the data is all out there...






Hi,
So you are saying the Mannol Safari 20W-50 has a viscosity of ~ 393 Cst @ 75 degrees F. Higher than the other quoted oils?
Also, much higher than all your other oils at lower than 75F?
How many cars are started at 75F?
Many thanks for clearing that up.
Cheers,
Iain.
 
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