Bottom line on 5W20

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Fast forward 29 years from 1980 to 2009. Isn't it possible that the advances made in engine oil chemistry, improved metals used in making an engine, now protect an engine better with a thinner more shear stable oil than it could in 1980, or 1990 or even 1999, etc.? I'd like to think so.
 
Originally Posted By: ZiTS


I really can not believe that some they are "1 upping" someone or something by mixing 5w-20 and 5w30. If the differences are already so close, is dilluting one with the other doing anything?! I think not.



New castrol hyper hybrid 5w-25 gives you the best parts of 20 and 30 wt oils, to protect your engine 50X better than 5-20 or 5-30 alone!
 
my answer from the thinner is better thread

After reading all these posts plus tons of others I have decided to use 5-30 instead of 5-20. Why you may ask? Dosent it just make sense! If you have questions about 5-20 being too thin, or shearing down to a 5-10 then why not just use 5-30? Is it too thick? No because its a 5 wt, it was recomended in the exact same engines before 5-20 became "the thing", and much thicker oil is recomended in everyother place besides north america.

But 5-30 is cheaper oil and just sheares down to 5-20: Ok well I guess you only have to live with the 5-30 for a month and then you have 5-20!

It dosent flow as well in cold temps: Its a 5wt how different can it be, and it has far better flow than the 10-30 that you used 10 years ago.

My oil cap says 5-20: well in a month it will be 5-20. Your owners manual probably says to only use oem fluids and parts too, or only service you car at the dealership but you dont do that.

5-20 gives me better gas milage: Barely! And remember the 5-30 will be 5-20 in a month so I think your ok.

I think the answer is obvious! But poke holes, I know its comming.

Like G.I. Joe said "Now you know, and knowing is half the battle!

Or some dumb rapper "and if you dont know, now you know n!gga"
 
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Being a 5W isn't the whole picture. A 5w30 is thicker at 40C than a 5W-20 is, and a 5W-40 is thicker yet. A 5W-50 can actually be twice as thick at 40C than a 5W-20 is. Just look at the spec sheets that are available from Pennzoil, Valvoline, Amsoil, etc.
 
Here.

Pennzoil Platinum.
Viscocity at 40C

5W-20 45.73
5w30 57.5
5W-50 106

It's the viscosity at 100C that changes the most when an oil sheers. Its 40C number is usually right around the same as when it was new. So a 5w30 will not end up being the same thing as a 5W-20 once it has sheered.
 
Originally Posted By: ADFD1
Fast forward 29 years from 1980 to 2009. Isn't it possible that the advances made in engine oil chemistry, improved metals used in making an engine, now protect an engine better with a thinner more shear stable oil than it could in 1980, or 1990 or even 1999, etc.? I'd like to think so.


I don't know, GM went from hand-fitted pistons to universal bore and piston sizing that led to all sorts of piston slapping fun. The "fix" was to coat the skirts in teflon..... Doesn't sound like superior construction to me, rather a cost-saving measure at the expense of precision.
 
Originally Posted By: ADFD1
That's GM, how about the Japanese cars, or Ford?


Ford's modulars last forever, so obviously they are doing something right.

I have no knowledge that I would deem "factual" in regard to how pistons are fitted in a Japanese engine, so I cannot comment one way or the other on that one.
 
The clearances in engines may not have changed since the 70's and 80's but many other things that affect oil have:

- wide spread use of fuel injection

- electronic ignition

- advanced computer controls

- overhead cams and roller rockers much more prevalent

- higher average specific power (hp per cubic inch)

etc

So the engines, plus the oil itself have advanced to the point where 5W20 is fine in most late model cars and trucks.
 
I will repost since nobody answer my questions earlier in this thread:

and the molecule size topic brings up a question I have:
Does thicker (heavier weight) oil have larger molecules than thinner (light weight) oil?????????????

shouldn't the molcules get bigger as they get hotter?



http://www.dantheoilman.com/fordoilfaq.doc

it claims MC 5w-20 is better oil than 5w30, but that was in 2004 or was it 2001, well what about now? is the base oil in 5w30 up to grade now that MC 5w30 is synblend too?
 
Originally Posted By: ryland
my answer from the thinner is better thread

After reading all these posts plus tons of others I have decided to use 5-30 instead of 5-20. Why you may ask? Dosent it just make sense! If you have questions about 5-20 being too thin, or shearing down to a 5-10 then why not just use 5-30? Is it too thick? No because its a 5 wt, it was recomended in the exact same engines before 5-20 became "the thing", and much thicker oil is recomended in everyother place besides north america.

But 5-30 is cheaper oil and just sheares down to 5-20: Ok well I guess you only have to live with the 5-30 for a month and then you have 5-20!

It dosent flow as well in cold temps: Its a 5wt how different can it be, and it has far better flow than the 10-30 that you used 10 years ago.

My oil cap says 5-20: well in a month it will be 5-20. Your owners manual probably says to only use oem fluids and parts too, or only service you car at the dealership but you dont do that.

5-20 gives me better gas milage: Barely! And remember the 5-30 will be 5-20 in a month so I think your ok.

I think the answer is obvious! But poke holes, I know its comming.

Like G.I. Joe said "Now you know, and knowing is half the battle!

Or some dumb rapper "and if you dont know, now you know n!gga"



I am tired of being nice to people who won't learn the principles of oil viscosity and what the J300 means.

Your comments are foolish. You would be embarrassed at your comment if you took the time to learn. I am not going to take the time to explain. Research. read and post less until you have a slightly better grasp on the subject matter.
 
Originally Posted By: Bryanccfshr
Originally Posted By: ryland
my answer from the thinner is better thread

After reading all these posts plus tons of others I have decided to use 5-30 instead of 5-20. Why you may ask? Dosent it just make sense! If you have questions about 5-20 being too thin, or shearing down to a 5-10 then why not just use 5-30? Is it too thick? No because its a 5 wt, it was recomended in the exact same engines before 5-20 became "the thing", and much thicker oil is recomended in everyother place besides north america.

But 5-30 is cheaper oil and just sheares down to 5-20: Ok well I guess you only have to live with the 5-30 for a month and then you have 5-20!

It dosent flow as well in cold temps: Its a 5wt how different can it be, and it has far better flow than the 10-30 that you used 10 years ago.

My oil cap says 5-20: well in a month it will be 5-20. Your owners manual probably says to only use oem fluids and parts too, or only service you car at the dealership but you dont do that.

5-20 gives me better gas milage: Barely! And remember the 5-30 will be 5-20 in a month so I think your ok.

I think the answer is obvious! But poke holes, I know its comming.

Like G.I. Joe said "Now you know, and knowing is half the battle!

Or some dumb rapper "and if you dont know, now you know n!gga"



I am tired of being nice to people who won't learn the principles of oil viscosity and what the J300 means.

Your comments are foolish. You would be embarrassed at your comment if you took the time to learn. I am not going to take the time to explain. Research. read and post less until you have a slightly better grasp on the subject matter.


Shame one bad apple spoils it for the whole bunch. I'm new but a long time lurker. You have some very informative posts.

AD
 
I apologize if it seems harsh. I don't know it all but I take the effort to learn as much as I can before making a declaritive statement on a topic.
 
So. Any comments regarding Scott Whitehead's post that I linked to and that thread?

Hey makes it clear 5W-20 is a no-no.
wink.gif
 
A disemfranchised employee is not a source of "credible" information. I really don't care who he claims he is or was, he is a "former" employee. THere were differences.
 
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Originally Posted By: Bryanccfshr
A disemfranchised employee is not a source of "credible" information. I really don't care who he claims he is or was, he is a "former" employee. THere were differences.

What exactly do you mean by "disenfranchised"? Does that mean "former"?

In many cases, a former employee is the only one who is willing to tell the truth because existing employees would get fired if they said anything derogatory about company statements or policy, even if those statements and policies were wrong. I am not saying that has happened in this case, but it is certainly possible.

If it were true that 5W-20 had no benefits other than increasing fuel economy, and that it could result in less engine protection than 5w30, no existing employee or company pronouncement is going to state that, since 5W-20 is the stated company policy.
 
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