0w20 vs 0w30 ??

[fins]

I'm sure this has been asked many times but I am trying to understand the difference between a 0w20 oil and a 0w30 oil.

At cold start up they would both flow the same ? But at operating temp the 0w30 would be thicker ? Would it offer better protection?

Would I get slightly less mpg with the 0w30?

I bought a different car at it calls for a 0w20 or a 5w20........I was thinking about using Mobil 10w30.

 

[Doog]

0W30 is thicker at operating temp.

 

[Doog]

Originally Posted By: fins

I bought a different car at it calls for a 0w20 or a 5w20........I was thinking about using Mobil 10w30.


Good choice.

 

[tig1]

Simple. If your calls for a 20wt then use 20. If your engine calls for a 30wt then use 30. Nothing else to add to this discussion.

 

[threeputtpar]

Originally Posted By: fins
At cold start up they would both flow the same ? But at operating temp the 0w30 would be thicker ? Would it offer better protection?

Would I get slightly less mpg with the 0w30?

I bought a different car at it calls for a 0w20 or a 5w20........I was thinking about using Mobil 10w30.


For the cold start up question, you'd have to compare the MRV and/or CCS numbers of the two oils in question. Both oils will be measured at the same temp, so the oil the lower numbers will flow better in the cold.

Less mpg? Potentially, since the 30 weight oil will be more viscous at operating temp than the 20 weight will. But that may be offset by the 20 weight flowing better at colder temps, giving slightly better mpgs while the car/oil warms up. Gues this all depends on if you put on more miles at full operating temp or while the car is less than full temp.

I cannot think of any reason to use a 10W-30 anymore now that most 5W30s are shear stable products. Skip the 10W-30 and use the 0W-20 like your car calls for.

 

[LeakySeals]

The 0w in a 0w20 is not the same as the 0w as a 0w40. Its a multi-range viscosity. The smaller the range, the less change in viscosity. Why you see people tossing abbreviations at you, its a combination of both.

 

[dave1251]

Originally Posted By: Doog
0W30 is thicker at operating temp.


And thick upon start up slightly.

 

[chubbs1]

I think the OP meant Mobil 1 0w30 and not 10w30 because that came out of left field. No reason at all to use a 0w30 but you can do it. Shoot I use 0w40 in my Hyundai 2.4GDi (not saying it is better or anything I will switch to the other end of the spectrum and use M1 0w20 next OCI.

 

[Rolla07]

Use whats recommended.

 

[fins]

Originally Posted By: chubbs1
I think the OP meant Mobil 1 0w30 and not 10w30 because that came out of left field. No reason at all to use a 0w30 but you can do it. Shoot I use 0w40 in my Hyundai 2.4GDi (not saying it is better or anything I will switch to the other end of the spectrum and use M1 0w20 next OCI.


Sorry for the error.....I meant Mobil 1 0w30.

 

[440Magnum]

Originally Posted By: LeakySeals
The 0w in a 0w20 is not the same as the 0w as a 0w40. Its a multi-range viscosity. The smaller the range, the less change in viscosity.



You didn't say that quite right. 0w30 is thicker all the time at all temperatures (in an ideal world) than 0w20, and 0w40 is thicker all the time at all temperatures than a 0w30. The range between the numbers on the two sides of the "w" does not work quite that simply either. A 0w40 oil will change viscosity quite a bit less over a wide temperature range than a 10w30 even though the 10w30's "range" between numbers is less. But the same is true of a 5w20. It tends to be very stable with temp, just like 0w40 oil. The 0w40 is just thicker all the time.

And for the OP- my example with a 10w30 brings up another point- if you're going to violate factory recommendations (please don't), then pick something besides an antiquated, outmoded grade like 10w30. At LEAST use a 5w30 or 0w30.

 

[lockguy]

Originally Posted By: 440Magnum
Originally Posted By: LeakySeals
The 0w in a 0w20 is not the same as the 0w as a 0w40. Its a multi-range viscosity. The smaller the range, the less change in viscosity.



You didn't say that quite right. 0w30 is thicker all the time at all temperatures (in an ideal world) than 0w20, and 0w40 is thicker all the time at all temperatures than a 0w30. The range between the numbers on the two sides of the "w" does not work quite that simply either. A 0w40 oil will change viscosity quite a bit less over a wide temperature range than a 10w30 even though the 10w30's "range" between numbers is less. But the same is true of a 5w20. It tends to be very stable with temp, just like 0w40 oil. The 0w40 is just thicker all the time.

And for the OP- my example with a 10w30 brings up another point- if you're going to violate factory recommendations (please don't), then pick something besides an antiquated, outmoded grade like 10w30. At LEAST use a 5w30 or 0w30.


I don't see the problem going with a slightly thicker oil. Many of the cars driven both here and over seas have a different oil spec'd depending on where the car is..

I have been using tropartic 5w-30 in my ford when spec'd for 5w-20 and can't tell the difference in fuel effeciency, smoothness etc.. Im only using the thicker oil because i get it on the cheap, not because i think it will protect better, which it may.

 

[pennzoil_guru]

Originally Posted By: tig1
Simple. If your calls for a 20wt then use 20. If your engine calls for a 30wt then use 30. Nothing else to add to this discussion.

 

[Errtt]

Just checked my book (2010 Tucson) and it says 5w-20 for better fuel economy.
But then when I look at the temp/SAE chart, it shows 10w-30 covers at just a tad under 0 up to 120 (F).
The bar for -30 to 120 (F) shows 5w-20, 5w-30.
Now next time I pop the hood, I'll have to see what the oil fill cap says.
I generally don't see 0 (F) here at home, or temps up to 120. But we do get triple digit temps every summer. Might hit 109+ just end of this week (forecast). I might see near 0 (F) during the winter if I'm up in the Sierra's.

So, looks like I can use 5w-20, 5w-30 or 10w-30. I dunno.

I haven't bought oil/filters yet as my 1st oil change is not due yet, but will have to decide when time comes.

 

[CATERHAM]

Originally Posted By: 440Magnum

But the same is true of a 5w20. It tends to be very stable with temp, just like 0w40 oil. The 0w40 is just thicker all the time.

Magnum you were on the right track up until this point.
The 5W-20 grade is not the most viscosity stable grade; considerably less so than the 0W-20 grade, and the 0W-30, 5W-30, 0W-40, 5W-40 and 5W-50 grades.

This is a better way to look at it. The 0W, 5W, 10W etc are viscosity ranges at very cold temp's; -40 degrees, -35C, -30C etc.
At hot oil temp's, the second number of the SAE oil grade applies; a 40wt is heavier than a 30wt which is heavier than a 20wt which is heavier than a 16wt oil and all those grades have viscosity ranges within themselves.

At less extreme cold temp's, the biggest factor that tells you how light an oil will be on start-up is the oil's viscosity index. For example a 0W-20 oil will be lighter at normal start-up temp's than a 5W-20 because it has a higher VI.
If a manufacturer spec's a 0W-20 grade vs a 5W-20, it has nothing to do with the fact the oil will still pump at -40 degrees and the 5W-20 will not, but rather that it will be lighter at more normal start-up temp's. And the sole reason is because the OEM 0W-20 oil has a significantly higher VI. It's just happens that in formulating high VI 20wt oils they wind up with a 0W rating.

Yes I know it is confusing but the SAE grade will only tell you so much and there is a lot of overlap when you start looking at individual oils.
If you really want to know the viscosity characteristics of a particular oil brand, you have to look up the actual PDS spec's from the companies website.

 

[azsynthetic]

Originally Posted By: tig1
Simple. If your calls for a 20wt then use 20. If your engine calls for a 30wt then use 30. Nothing else to add to this discussion.


Then this forum has no purpose.

 

[surfstar]

Originally Posted By: azsynthetic
Originally Posted By: tig1
Simple. If your calls for a 20wt then use 20. If your engine calls for a 30wt then use 30. Nothing else to add to this discussion.


Then this forum has no purpose.


Boring answer, yes, but still some of the best advice that people should actually pay attention to on this forum. Don't try to out-think the auto engineers.

 

[440Magnum]

Originally Posted By: CATERHAM
Originally Posted By: 440Magnum

But the same is true of a 5w20. It tends to be very stable with temp, just like 0w40 oil. The 0w40 is just thicker all the time.

Magnum you were on the right track up until this point.
The 5W-20 grade is not the most viscosity stable grade; considerably less so than the 0W-20 grade, and the 0W-30, 5W-30, 0W-40, 5W-40 and 5W-50 grades.



Good catch- I actually meant to type 0w20 in that line of my response instead of 5w20. The whole SAE system is running out of resolution as we go thinner ;-) So you can't take the "span" between the numbers BY ITSELF as being indicative of stability. These modern thin oils can still be very stable at high temperature- I would wager that if you took a modern 0w20 and heated it to 350F (extreme overheat conditions) it would hold its viscosity far better than a typical 10w30 or 15w40.

And another point to be made: people are always wanting to think of comparing very different multigrade oils in very simple terms (eg, "is a 5w20 worse or better than a 0w30?"). It just aint simple and you cannot make it so. On top of all the inherent complications, there are variations within any one grade from brand to brand and even year to year as oils evolve. And lots of things happen in between, above, and below the temps where the API ratings are determined. "What happens to Brand A 0w40 if the oil temp exceeds 300F versus what happens to Brand B 15w40 under those conditions?" for example.