Syn thinner than dino...5w30 or 10w30?

[FastSUV]

My g/f's '08 G6 GXP VVT 3.6L calls for 5w30 I think. Per another thread, I will be switching it to PP for the 1st oil change (new to her, 15k on the car right now with house dino from the car lot).

But, since synthetics are supposed be thinner, then wouldn't a 10w30 PP fill be better than using 5w30 PP?

This motor did not come factory with Mobil-1 like many GM hp motors, but it probably should have. The Chevy dealer used cars she just bought it from said they did an oil change on it with 5w30 Mobil bulk dino oil. After that dino gets 3k on it, I will be switching to PP (per concensus on a previous thread I started)but am curious what people have to say about using 10w30 instead of 5w30 due to my reasons above.

 

[AndyH]

Synthetic isn't necessarily "thinner" than conventional oil. I'd go with the 5W-30 PP and be done with it. My $0.02

 

[FrankN4]

Originally Posted By: AndyH
Synthetic isn't necessarily "thinner" than conventional oil. I'd go with the 5W-30 PP and be done with it. My $0.02


This is correct. I would also go with the PP if you like Pennzoil oil.

Synthetic 5W-30 is not necessarily thinner. Just remember that 5W-30 means a 30 GRADE oil with a given cold flow. A 30 grade can be as "thin" as a 9.3 100C cSt to as "thick" as a 12.49 100C cSt. A synthetic will be molecularly more uniform and will therefore flow better.

 

[tig1]

One thing about synthetic oil is that it doesn't thicken over time the way dino does. Even after 10 to 12,000 miles my syn. drains very well.




M1 5-30

 

[Steve S]

Originally Posted By: tig1
One thing about synthetic oil is that it doesn't thicken over time the way dino does. Even after 10 to 12,000 miles my syn. drains very well.




M1 5-30
???? what?

 

[FrankN4]

Originally Posted By: tig1
One thing about synthetic oil is that it doesn't thicken over time the way dino does.


"it doesn't thicken over time the way dino does."

If that is your qualifier, then you are correct. However, synthetics will indeed thicken, some more/more easily/more ofter than others.

If you look at the data sheets for a given oil, look for the Noack Volatility. This is an indication of how resistant an oil is to volatilizing, boiling off and thickening as it were. The lower the number, the better. You will find conventional oils with a Noack of 15, minimum to meet specifications, through synthetics with a Noack of 6-7. One of the most popular synthetics on BITOG has a Noack of 11. Better than a conventional but it can volatize.

Oil also thickens because of contaminants such as blow-by carbon/soot from the combustion process. This happens to conventional and synthetics.

I believe and am convinced that synthetics handle thickening problems better than conventional(dino), but they are not immune

 

[Nickdfresh]

I'd use the PP 5W-30 as I like the way it meets the Acura/Honda HTO-06 spec, and it is about the same 'thickness' as the 10W-30 at temperature...

 

[tig1]

Originally Posted By: FrankN4
Originally Posted By: tig1
One thing about synthetic oil is that it doesn't thicken over time the way dino does.


"it doesn't thicken over time the way dino does."

If that is your qualifier, then you are correct. However, synthetics will indeed thicken, some more/more easily/more ofter than others.

If you look at the data sheets for a given oil, look for the Noack Volatility. This is an indication of how resistant an oil is to volatilizing, boiling off and thickening as it were. The lower the number, the better. You will find conventional oils with a Noack of 15, minimum to meet specifications, through synthetics with a Noack of 6-7. One of the most popular synthetics on BITOG has a Noack of 11. Better than a conventional but it can volatize.

Oil also thickens because of contaminants such as blow-by carbon/soot from the combustion process. This happens to conventional and synthetics.

I believe and am convinced that synthetics handle thickening problems better than conventional(dino), but they are not immune





Yes ,you are correst. As I said synt doesn't thicken the way dino does. My only experience with synt has been with M1 so I,ve never seen it thicken, at least so far as I could tell.

 

[jldcol]

If you compare a syn 10w30 and a dino 10w30, the syn can have no vii's and therefore is real 30wt. The dino 10w30 has some/a lot of vii's and is a 20 wt. without them so the syn is not thinner it's actually thicker.

 

[Zaedock]

Originally Posted By: jldcol
If you compare a syn 10w30 and a dino 10w30, the syn can have no vii's and therefore is real 30wt. The dino 10w30 has some/a lot of vii's and is a 20 wt. without them so the syn is not thinner it's actually thicker.


So dino 10W30 is imaginary 30 weight oil?

 

[CharBaby]

Originally Posted By: Zaedock
Originally Posted By: jldcol
If you compare a syn 10w30 and a dino 10w30, the syn can have no vii's and therefore is real 30wt. The dino 10w30 has some/a lot of vii's and is a 20 wt. without them so the syn is not thinner it's actually thicker.


So dino 10W30 is imaginary 30 weight oil?


No! What I beleive that jldcol means is, the syn oil is developed into a 30 weight oil and a dino oil will requier VII's to become a 30 weight oil. I wouldn't call that imaginary, it just needed a little help.

What I beleive is that a 10W30 grade oil is actually a 10 oil to start with and it needs VII's to maintain a 30 at temp. Same with a 5W30. It starts out being a 5.

This may be incorrect but Im always willing to learn more.

 

[jldcol]

Dino 10w30 is not imaginary, but it's not a real 30wt. either, it's a analog that approximates a 30wt. with adds. People on this forum often say in general terms that syn is thinner than dino, even in the same grade, but it is more likely that the syn is thicker. Example 10w30 syn with no vii's is a 30wt. at all temps and a 20w50 dino is about 10 cst. at 100degC for the base oil, so a 30wt. without vii's. So in these terms that's about 2 grades thicker oil needed to get the same thickness, at least in terms of base oil visc.

 

[Zaedock]

Originally Posted By: jldcol
Dino 10w30 is not imaginary, but it's not a real 30wt. either, it's a analog that approximates a 30wt. with adds. People on this forum often say in general terms that syn is thinner than dino, even in the same grade, but it is more likely that the syn is thicker. Example 10w30 syn with no vii's is a 30wt. at all temps and a 20w50 dino is about 10 cst. at 100degC for the base oil, so a 30wt. without vii's. So in these terms that's about 2 grades thicker oil needed to get the same thickness, at least in terms of base oil visc.


I was being a little sarcastic. Even though your info may be true, dissecting a 10W30 dino has no real relevance in comparing the operating thickness of dino vs. syn. It is what it is. At operating temp, it IS a REAL 30wt, most being between 10-11cSt. It is not more likely that the syn is thicker. It depends on the manufacturer. There are plenty of cases where a company's 10w30 dino is thicker than it's syn counterpart at operating temps.

 

[jldcol]

If you read my post I hoped that it was clear I was talking about the base oils of each. Most of the time oil is below ideal temp, so the 100degc numbers are less relevant anyway. Even at operating temps a real 30wt. and a analog 30wt. are different, if say you compare wear rates. The real 30wt. has lower wear than a 30wt. analog, search here and other forum to find that info.

 

[farrarfan1]

Real 30wt? Analog 30wt?

 

[jldcol]

A analog is a thinner base oil with vii's added to approximate the functional characteristics of a real,( a straight, mono grade oil). Real 30wt. oils are about 9.5-12.5 cst. at 100degC, mono grade typically upper 1/2 range or 11-12 cst. A 10w30 dino oil without any vii's base oil is about 6 or so cst. and this is a 20wt. oil and near the bottom of that range. The only way for a multigrade to get good cold flow numbers is to be rather thin to start and hope the vii's hold up under use and keep it in grade. Hope this is more clear.

 

[Zaedock]

Originally Posted By: jldcol
If you read my post I hoped that it was clear I was talking about the base oils of each. Most of the time oil is below ideal temp, so the 100degc numbers are less relevant anyway. Even at operating temps a real 30wt. and a analog 30wt. are different, if say you compare wear rates. The real 30wt. has lower wear than a 30wt. analog, search here and other forum to find that info.


I read the post and it's still irrelevant info. Who cares about the viscosity of the base oil used in the dino. I don't put the base oil into my engine, I put the final product into my engine. The OP wants to know if syn is thinner than dino. The answer is: It depends on the manufacturer.

Originally Posted By: jldcol
Even at operating temps a real 30wt. and a analog 30wt. are different, if say you compare wear rates..

Dude, where do you get your info? If a syn 10W30 is 10.5cSt @100*C and a dino 10W30 is 10.5cSt @100*C, then please tell me; how is the viscosity different?

Originally Posted By: jldcol
The real 30wt. has lower wear than a 30wt. analog, search here and other forum to find that info.


That's not true. Let's take the Jeep 4.0L: Mobil 1 typically shows higher Fe numbers in this engine than dino. Go take a look at one of Bill's (from Utah) dino UOAs and tell me he'd get lower wear from syn.
There are many, many awesome UOA's on engines running syn. However, I'd bet there are just as many on dino too.

 

[jldcol]

Until the oil is heated up and the vii's function as intended the viscosity of the base oil is going to determine how it works. This is probably why syn typically does better than dino, less dependent on vii's. As for wear rates, on the aircraft pages straight 30wt. did better that 10w30. As for base oil thats primarily what you put in the engine and until the temp allows the additives to fully work thats all that is working, save for some AW stuff. 6 is smaller that 10 so dino is thinner and syn is thicker, the opposit of common thought.

 

[Greggy_D]

And BITOG falls 500 feet further into the Abyss.......

 

[Zaedock]

Originally Posted By: jldcol
The real 30wt. has lower wear than a 30wt. analog, search here and other forum to find that info.


Well, if this is true, please explain the results of the following UOA.

https://bobistheoilguy.com/forums/threads/07-corolla-yb-penn-5w30-4814-miles.92788/

Originally Posted By: jldcol
... People on this forum often say in general terms that syn is thinner than dino, even in the same grade, but it is more likely that the syn is thicker...


When you read this UOA, please take notice that the dino oil is ever so slightly thicker than the syn.