does 5w-20 thin out during use?

Pennzoil motor oil
Status
Not open for further replies.
K

kmrcstintn

Joined
May 11, 2006
Messages
672
Location
Palmyra, PA
I am asking this out of curiosity since my Jeep calls for 5w-20 oil...

does 5w-20 conventional oil, such as Pennzoil or Valvoline, thin out during use? if so, what weight does it become?

are synthetic blends and full synthetic oils in 5w-20 affected the same way?

and finally, can the thinned out oil continue to protect, clean, and transfer heat effectively enough? thanks
 
Originally Posted By: The Critic
Yup, just like any other oil. But they rarely drop out of the 20wt range.

It's safe to say that they NEVER drop out of grade in terms of their kinematic viscosity spec's, but they do in terms of HTHSV.
Since all 5w20 conventionals have a nominal HTHSV of 2.6cP, the minimum for the 20wt grade, any oil shear at all will drop them technically out of grade.

The point is it doesn't matter. All vehicle manufacturers allow for a good 15% of oil shear before condemning an oil and the 5W-20 grade rarely shears that much. The 20wt grade is most shear resistant SAE grade.
 
Originally Posted By: CATERHAM



The point is it doesn't matter. All vehicle manufacturers allow for a good 15% of oil shear before condemning an oil and the 5W-20 grade rarely shears that much. The 20wt grade is most shear resistant SAE grade.


I'm certainly not an advocate of running 0w20 in everything under the sun, but I get amused at all the hand-wringing and worry when someone buys a car or truck and the manual RECOMMENDS 5w20 or 0w20. Its been proven SO many times that engines designed for Xw20 live enormously long and happy lives on it, even in the severest conditions. In quality brands, its a robust grade that as you point out is very stable. It won't be optimal for an engine that really needs a thicker oil, but its silly to feed an engine made for Xw20 a thicker oil and thinking its adding safety margin. It usually doesn't, and in some cases probably is doing the opposite.
 
Originally Posted By: 440Magnum
Originally Posted By: CATERHAM



The point is it doesn't matter. All vehicle manufacturers allow for a good 15% of oil shear before condemning an oil and the 5W-20 grade rarely shears that much. The 20wt grade is most shear resistant SAE grade.


I'm certainly not an advocate of running 0w20 in everything under the sun, but I get amused at all the hand-wringing and worry when someone buys a car or truck and the manual RECOMMENDS 5w20 or 0w20. Its been proven SO many times that engines designed for Xw20 live enormously long and happy lives on it, even in the severest conditions. In quality brands, its a robust grade that as you point out is very stable. It won't be optimal for an engine that really needs a thicker oil, but its silly to feed an engine made for Xw20 a thicker oil and thinking its adding safety margin. It usually doesn't, and in some cases probably is doing the opposite.



+1 .... Well said....
 
Originally Posted By: Oregoonian
Originally Posted By: 440Magnum
Originally Posted By: CATERHAM



The point is it doesn't matter. All vehicle manufacturers allow for a good 15% of oil shear before condemning an oil and the 5W-20 grade rarely shears that much. The 20wt grade is most shear resistant SAE grade.


I'm certainly not an advocate of running 0w20 in everything under the sun, but I get amused at all the hand-wringing and worry when someone buys a car or truck and the manual RECOMMENDS 5w20 or 0w20. Its been proven SO many times that engines designed for Xw20 live enormously long and happy lives on it, even in the severest conditions. In quality brands, its a robust grade that as you point out is very stable. It won't be optimal for an engine that really needs a thicker oil, but its silly to feed an engine made for Xw20 a thicker oil and thinking its adding safety margin. It usually doesn't, and in some cases probably is doing the opposite.



+1 .... Well said....


I was unaware 5w20 or 0w20 had been around long enough to make that claim. Thought only new engines were running it.
 
Last edited:
Originally Posted By: LeakySeals
Originally Posted By: Oregoonian
Originally Posted By: 440Magnum
Originally Posted By: CATERHAM



The point is it doesn't matter. All vehicle manufacturers allow for a good 15% of oil shear before condemning an oil and the 5W-20 grade rarely shears that much. The 20wt grade is most shear resistant SAE grade.


I'm certainly not an advocate of running 0w20 in everything under the sun, but I get amused at all the hand-wringing and worry when someone buys a car or truck and the manual RECOMMENDS 5w20 or 0w20. Its been proven SO many times that engines designed for Xw20 live enormously long and happy lives on it, even in the severest conditions. In quality brands, its a robust grade that as you point out is very stable. It won't be optimal for an engine that really needs a thicker oil, but its silly to feed an engine made for Xw20 a thicker oil and thinking its adding safety margin. It usually doesn't, and in some cases probably is doing the opposite.



+1 .... Well said....


I was unaware 5w20 or 0w20 had been around long enough to make that claim. Thought only new engines were running it.


LeakySeals.....you learn something new every day on this forum....

My ride (03'Ford Focus)....was speced for 5w20 originally....and I'll be using Mobil 1 0w20 on my next oil change.
 
%w20 has been used for a while and I think it has proven itself to be very good for the engines it is spec'd for. Use with confidence. Look at the spec sheets of most brand's 5w20's to 5w30's and I think you will be surprised to see 5w20 is usually of slightly higher quality base stock. NOT ALWAYS, But quite often.
 
Originally Posted By: LeakySeals
Originally Posted By: Oregoonian
Originally Posted By: 440Magnum
Originally Posted By: CATERHAM



The point is it doesn't matter. All vehicle manufacturers allow for a good 15% of oil shear before condemning an oil and the 5W-20 grade rarely shears that much. The 20wt grade is most shear resistant SAE grade.


I'm certainly not an advocate of running 0w20 in everything under the sun, but I get amused at all the hand-wringing and worry when someone buys a car or truck and the manual RECOMMENDS 5w20 or 0w20. Its been proven SO many times that engines designed for Xw20 live enormously long and happy lives on it, even in the severest conditions. In quality brands, its a robust grade that as you point out is very stable. It won't be optimal for an engine that really needs a thicker oil, but its silly to feed an engine made for Xw20 a thicker oil and thinking its adding safety margin. It usually doesn't, and in some cases probably is doing the opposite.



+1 .... Well said....


I was unaware 5w20 or 0w20 had been around long enough to make that claim. Thought only new engines were running it.


I used Mobil 1 5w20 in 1978.
 
Have used 5w30 and 0&5w-20 in both of my last 2 vehicles. There has been no substantial difference between them in MPG's, sound of the engine, and oil usage. The only noticeable difference is that with 30 weight, at lower RPM's the motor seems more sluggish, until the motor warms up fully.
 
How long will it take before people stop questioning the protection offered by 5W20? What was it for 5W30 when the big switch over from 10W30 started?
 
Caterham: After your comment about them not dropping out of grade I had to check that out.

Sure enough all the used oil analysis I checked showed them well within grade even with long OCI's.

You seem very knowledgeable about oil related matters.
 
(tig wrote) I used Mobil 1 5w20 in 1978. In cars that I was using 10W40 in.
grin.gif
My point is, if it worked for tig back then. There sure shouldnt be any problems now.
 
Last edited:
Originally Posted By: lexus114
(tig wrote) I used Mobil 1 5w20 in 1978. In cars that I was using 10W40 in.
grin.gif
My point is, if it worked for tig back then. There sure shouldnt be any problems now.


Pretty knuckle headed reasoning here. "if it worked for tig back then" ?

I guess you are saying if the vehicle called for a 5w20 back in 1978 then fine,

But if the vehicle called for a 10w40 and a 5w20 was being used without used oil analysis etc then this is knuckle headed.
 
Originally Posted By: ZZman
Caterham: After your comment about them not dropping out of grade I had to check that out.

Sure enough all the used oil analysis I checked showed them well within grade even with long OCI's.

You seem very knowledgeable about oil related matters.

He certainly is. I however gotta play devils advocate. He does qualify pretty much every statement he makes. It's tough to win an argument with him.
 
Originally Posted By: virginoil
Originally Posted By: lexus114
(tig wrote) I used Mobil 1 5w20 in 1978. In cars that I was using 10W40 in.
grin.gif
My point is, if it worked for tig back then. There sure shouldnt be any problems now.


Pretty knuckle headed reasoning here. "if it worked for tig back then" ?

I guess you are saying if the vehicle called for a 5w20 back in 1978 then fine,

But if the vehicle called for a 10w40 and a 5w20 was being used without used oil analysis etc then this is knuckle headed.


In the 70s used oil analysis were the last thing we had money to waste on. As for the knuckle headed remark, see my PM to you.
 
Status
Not open for further replies.

Similar threads

M
  • Locked
Motorcraft 5W-20 = Synthetic blend
2
Replies
20
Views
19K
Ken2
G
  • Locked
Does Mobil 1 5w20 thicken or thin out?
Replies
4
Views
833
gregk001
B
  • Locked
5W-20 vs. 5W-30 vs 10W-30
5 6 7
Replies
136
Views
198K
Slick 55
T
  • Locked
Thin out Havoline Synthetic 5W-30?
Replies
7
Views
2K
dustyjoe1
mosaud1998
  • Locked
Running 5w-40 oil in B58
2 3
Replies
53
Views
18K
BMWTurboDzl
Back
Top Bottom