5W20 VS 5W30

glum · May 7, 2011

What I was trying to say was in response to:

Originally Posted By: retmil46
Then, for 2005, right in the middle of the same version of the engine (2001 - 2008 mentioned above), Chrysler suddenly started specing 0W or 5W20 oil - with no apparent major change in engine design.

Maybe they didn't change any outright specs but tightened the tolerances (variance in clearances). I don't know a bloody thing so I'm just grasping in the air...

Gene K · May 7, 2011

Originally Posted By: Steve S
There isn't a whole lot of difference between the 2 oils.

If its out of warranty use which ever one makes you feel the best. If its in warranty use which ever is going to give you the least trouble with the manufacturers rep if an engine has to be replaced.

Really all this fuss over an average of 15% viscosity difference (Sometimes as little as 3%) that most 5W30 Energy Conserving Oil is going to thin within a few hundred miles anyway.

Steve S · May 7, 2011

https://bobistheoilguy.com/forums/posts/1919631/ Read the post for, if thicker oil works in Ford engines. Internt experts beware.

brick · May 7, 2011

I don't care about fuel economy i want engine protection,the best i can get.
What about those additives like lucas and others,do they really offer MORE protection?
I try to stay with 5w30 as the cap say's but do change now and then.

BlueOvalFitter · May 7, 2011

Ok,time to chime in.The reason I asked this question is I have been doing alot of reading lately.I've read so many stories about how Ford might not be filling crankcases with 5W20,but instead 5W30! Does anyone really know that they are getting 5W20 instead of 5W30 at a Ford dealership? They buy in bulk so who really knows if it's even MC oil they are using!The only real way to get 5W20 is to buy it in bottles or jugs.Opinions?

BlueOvalFitter · May 7, 2011

Originally Posted By: mattd
whats the oil cap/owners manual say?

It can't talk.......

But it does have "5W20" printed on it.

demarpaint · May 7, 2011

^^^^^
I'm sure most dealers who buy oil in bulk, buy based on price. So if 5W30 or 10W30 is cheaper, that's what's going on your car, no matter what the fill cap calls for. It isn't only Ford playing those games. I worked for Honda, Nissan, Kia, Suzuki, and VW, they all played games with bulk oil. Bottom line, the only way to know what oil is going in your car is to change it yourself, or if you decide to bring your own oil to the dealer watch him pour it in. I knew more than one dealer tech that had a nice stash of oil supplied by customers who didn't watch them pour it into their cars. They got bulk oil, and the tech got their oil.

Gene K · May 7, 2011

Originally Posted By: brick
I don't care about fuel economy i want engine protection,the best i can get.
What about those additives like lucas and others,do they really offer MORE protection?
I try to stay with 5w30 as the cap say's but do change now and then.

The problem is how you define it. A 5W30 might give you better bearing protection when oil temps are over 250F at the expense of increased wear at anything between freezing and 180F sump temps (compared to 5W20).

As to Lucas as I understand it you are basically adding viscosity index improvers. Why not just by 5W30 instead of 5W20 if thats what you want?

Clevy · May 7, 2011

Originally Posted By: Gene K
Originally Posted By: brick
I don't care about fuel economy i want engine protection,the best i can get.
What about those additives like lucas and others,do they really offer MORE protection?
I try to stay with 5w30 as the cap say's but do change now and then.

The problem is how you define it. A 5W30 might give you better bearing protection when oil temps are over 250F at the expense of increased wear at anything between freezing and 180F sump temps (compared to 5W20).

As to Lucas as I understand it you are basically adding viscosity index improvers. Why
not just by 5W30 instead of 5W20 if thats what you want?

Sorry bud but 5w-20 and 5w30 are the same viscosity when cold hence that number 5 up front. The second number is viscosity at operating temp so your entire statement is incorrect. I would suggest sticking around here awhile. And if you want the best protection as far as cold flow go with a 0w-30. My mustang calls for 5w-20 but after spending countless hours on this forum I went with AMSOIL Signature Series 0w30 and my mileage went up 2 mpg. I now use that oil in every vehicle my wife and I own. These once a year oil changes are fantastic and blackstone tells me there is lots of life left when I send in for analysis.

biodiesel · May 7, 2011

Originally Posted By: Clevy
Originally Posted By: Gene K
Originally Posted By: brick
I don't care about fuel economy i want engine protection,the best i can get.
What about those additives like lucas and others,do they really offer MORE protection?
I try to stay with 5w30 as the cap say's but do change now and then.

The problem is how you define it. A 5W30 might give you better bearing protection when oil temps are over 250F at the expense of increased wear at anything between freezing and 180F sump temps (compared to 5W20).

As to Lucas as I understand it you are basically adding viscosity index improvers. Why
not just by 5W30 instead of 5W20 if thats what you want?

Sorry bud but 5w-20 and 5w30 are the same viscosity when cold hence that number 5 up front. The second number is viscosity at operating temp so your entire statement is incorrect. I would suggest sticking around here awhile. And if you want the best protection as far as cold flow go with a 0w-30. My mustang calls for 5w-20 but after spending countless hours on this forum I went with AMSOIL Signature Series 0w30 and my mileage went up 2 mpg. I now use that oil in every vehicle my wife and I own. These once a year oil changes are fantastic and blackstone tells me there is lots of life left when I send in for analysis.

His entire statement is not incorrect and you shouldn't be so hasty to assume you know more than someone else.

You just suggested to Gene, who has been here 7 years longer than you, to "stick around here awhile". I laughed.

demarpaint · May 7, 2011

Originally Posted By: Clevy
Originally Posted By: Gene K
Originally Posted By: brick
I don't care about fuel economy i want engine protection,the best i can get.
What about those additives like lucas and others,do they really offer MORE protection?
I try to stay with 5w30 as the cap say's but do change now and then.

The problem is how you define it. A 5W30 might give you better bearing protection when oil temps are over 250F at the expense of increased wear at anything between freezing and 180F sump temps (compared to 5W20).

As to Lucas as I understand it you are basically adding viscosity index improvers. Why
not just by 5W30 instead of 5W20 if thats what you want?

Sorry bud but 5w-20 and 5w30 are the same viscosity when cold hence that number 5 up front. The second number is viscosity at operating temp so your entire statement is incorrect.

crazyoildude · May 7, 2011

that is the whole idea you want your oil to flow FAST

glum · May 7, 2011

That's it, I'm loading up my crankcase with WD-40!

I'll post UOA results in 8,000 miles.

crazyoildude · May 7, 2011

Use the 5w20, like i said before maybe just maybe the people that design the engines that require the 5w20 know something about the engines they build maybe more than the rest of us...

glum · May 7, 2011

^ That idea has been floated before, the response to which usually ends up being something like "Sure, they know more, but their agenda is appeasing government-mandated fleet fuel economy ratings and getting the drivetrain past the warranty period... Rather than truly long-term engine life."

crazyoildude · May 7, 2011

blue
the dealers buy any oil they want some use 5w30 in everything but that does not make it correct from the factory it is 5w20 i have sent 2 oil samples of new fords and they were both 5w20

crazyoildude · May 7, 2011

their agenda? being government mandated and to last only through the warantee?
Being in the engine rebuilding business i wish that were true because i would be doing thousands of bad engines caused by the bad 5w20... Many engines are waranteed for 100,000 miles that require 5w20 and they run a long time past that

BlueOvalFitter · May 8, 2011

Originally Posted By: crazyoildude
their agenda? being government mandated and to last only through the warantee?
Being in the engine rebuilding business i wish that were true because i would be doing thousands of bad engines caused by the bad 5w20... Many engines are waranteed for 100,000 miles that require 5w20 and they run a long time past that

Ok,as an engine builder,would you use 5W30 over 5W20?

Gene K · May 8, 2011

Originally Posted By: BlueOvalFitter
Originally Posted By: crazyoildude
their agenda? being government mandated and to last only through the warantee?
Being in the engine rebuilding business i wish that were true because i would be doing thousands of bad engines caused by the bad 5w20... Many engines are waranteed for 100,000 miles that require 5w20 and they run a long time past that

Ok,as an engine builder,would you use 5W30 over 5W20?

Professional engine builders use oil from 0 to 70 Grade. It depends on application.

cmf · May 8, 2011

Originally Posted By: Clevy
Originally Posted By: Gene K
Originally Posted By: brick
I don't care about fuel economy i want engine protection,the best i can get.
What about those additives like lucas and others,do they really offer MORE protection?
I try to stay with 5w30 as the cap say's but do change now and then.

The problem is how you define it. A 5W30 might give you better bearing protection when oil temps are over 250F at the expense of increased wear at anything between freezing and 180F sump temps (compared to 5W20).

As to Lucas as I understand it you are basically adding viscosity index improvers. Why
not just by 5W30 instead of 5W20 if thats what you want?

Sorry bud but 5w-20 and 5w30 are the same viscosity when cold hence that number 5 up front. The second number is viscosity at operating temp so your entire statement is incorrect. I would suggest sticking around here awhile. And if you want the best protection as far as cold flow go with a 0w-30. My mustang calls for 5w-20 but after spending countless hours on this forum I went with AMSOIL Signature Series 0w30 and my mileage went up 2 mpg. I now use that oil in every vehicle my wife and I own. These once a year oil changes are fantastic and blackstone tells me there is lots of life left when I send in for analysis.

The first number actually means that it meets a certain specification at a certain temperature. Nothing less, nothing more.

An easy example is comparing the viscosity at 40 C from two mobil 1 product data sheets.

0w-30 62.9 cSt

5w30 61.7 cSt

So at 40 C the 0w30 is actually thicker than the 5w30.

You can read more about the requirements for the SAE grades at http://www.roymech.co.uk/Useful_Tables/Tribology/Viscosity.html

Edit: I live in Florida so I take "cold" to mean the temperature when the car is first started; which for me is above 30 C most of the year.

Also since this is about 5w-20 vs 5w30, here's Mobil 1 5w-20:

Much thinner than the 5w30 with 49.8 cSt at 40 C

You can also compare all the syntec grades on one PDS: here

5w-20 is 49.35 cSt at 40 C and 5w30 is 62.64 cSt at 40 C. Similar trends are followed for all major synthetic brands, I just used these because they came to mind for brands that offer 0w/5w/10w in one product line.

5W20 VS 5W30

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