Syn thinner than dino...5w30 or 10w30?
- Thread starter FastSUV
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I'll finish haranging with this, in the old days all they had was base oil really, group1 and maybe group2 in OTR diesels, along with none/lousy additives. This stuff is ok, if changed often enough, but it leaves deposits, rust, has to much wear, acidifies and eats bearings, and not to good for mpgs. The additives especially modern ones largely are there to counteract the bad tendencies of the base oil, namely the things I mentioned. Now with modern base oils group2/2+ is really good enough, and group 3 is overkill, well until it got a lot cheaper which it did, really after group2/2+ just go ahead to PAO or other real syn. This is for those talking about the total product like by magic the 80-95% of the stuff in the bottle now doesn't matter. Base oil is extremely important, the better it is the less adds needed and since adds wear out and oil does not the better base oil will give you a better product, here I am talking about the same add pack added to various quality base oils. With the few add pack producers out there, really little difference between them, especially the rated ones.
Originally Posted By: BuickGN
Very good info jldcol! Makes me feel better about my synthetic straight 30wt decision. Your points are completely understood.
Some of it is. Syn always being thicker or producing better wear numbers are not.
Very good info jldcol! Makes me feel better about my synthetic straight 30wt decision. Your points are completely understood.
Some of it is. Syn always being thicker or producing better wear numbers are not.
Originally Posted By: Zaedock
Originally Posted By: BuickGN
Very good info jldcol! Makes me feel better about my synthetic straight 30wt decision. Your points are completely understood.
Some of it is. Syn always being thicker or producing better wear numbers are not.
What he is saying is take the VIIs out of the dino oil and you have something around a 6cst base oil. If the VIIs shear, you're running a 6cst oil.
Since a synthetic can get the 10w-30 rating without VIIs, it's a true 30wt base oil.
I know it's a different subject but I don't put much weight in UOAs when used for wear.
Originally Posted By: BuickGN
Very good info jldcol! Makes me feel better about my synthetic straight 30wt decision. Your points are completely understood.
Some of it is. Syn always being thicker or producing better wear numbers are not.
What he is saying is take the VIIs out of the dino oil and you have something around a 6cst base oil. If the VIIs shear, you're running a 6cst oil.
Since a synthetic can get the 10w-30 rating without VIIs, it's a true 30wt base oil.
I know it's a different subject but I don't put much weight in UOAs when used for wear.
I believe that in a given grade the syn is always thicker that the equivalent dino namely in base oil visc and less if any need fo vii's in the syn. All the adds can do is alter the properties of the base oil, and vii's can't make a thin oil thick, they can just make it pump like it was a thick oil. Except for the oil pump I don't think any thing else in the engine responds to this additized oil like it was a thick one. Vii's make the oil pump harder at a given temp, they do not lubricate, in fact they probably are the chief ingredient of sludge and other deposites in engine. To compare a 10-20wt. base oil to a real 30wt. syn is quite a big leap, I think. As to wear numbers a few UOA's is not enough proof and then it's not the right kind of proof anyway, you need teardowns of many, many engines and measurements on them to reach a conclusion. In bearings the vii's string out and can get sheared up and no longer function, the real 30wt. here has more lubricating molecules, and the thinner analog a mix of oil(lubricant) and vii's (not lubricants, and taking up space that lube molecules could). Wear is a factor of lack of lubricating largely so a less lubricating oil has more wear.
Originally Posted By: jldcol
To compare a 10-20wt. base oil to a real 30wt. syn is quite a big leap, I think.
Once again, the original poster didn't ask to go off on a tangent about the base oil. He simply asked if Syn is thinner than Dino. The dino oil, being comprised of the base oil and VII's can be thicker than an equivalent grade syn at operating temp. That's the bottom line.
To compare a 10-20wt. base oil to a real 30wt. syn is quite a big leap, I think.
Once again, the original poster didn't ask to go off on a tangent about the base oil. He simply asked if Syn is thinner than Dino. The dino oil, being comprised of the base oil and VII's can be thicker than an equivalent grade syn at operating temp. That's the bottom line.
Originally Posted By: Zaedock
Originally Posted By: jldcol
To compare a 10-20wt. base oil to a real 30wt. syn is quite a big leap, I think.
Once again, the original poster didn't ask to go off on a tangent about the base oil. He simply asked if Syn is thinner than Dino. The dino oil, being comprised of the base oil and VII's can be thicker than an equivalent grade syn at operating temp. That's the bottom line.
The VII enhanced oil reverts back to it's 10-20wt base oil under pressure in a bearing while a VII-less straight 30wt that is a true 30wt base oil retains it's viscosity. So in reality, even though both pump and pour as a 30wt, when the going gets tough, the base oil (pre VII) does matter because that is the weight that is actually lubing the bearing.
Originally Posted By: jldcol
To compare a 10-20wt. base oil to a real 30wt. syn is quite a big leap, I think.
Once again, the original poster didn't ask to go off on a tangent about the base oil. He simply asked if Syn is thinner than Dino. The dino oil, being comprised of the base oil and VII's can be thicker than an equivalent grade syn at operating temp. That's the bottom line.
The VII enhanced oil reverts back to it's 10-20wt base oil under pressure in a bearing while a VII-less straight 30wt that is a true 30wt base oil retains it's viscosity. So in reality, even though both pump and pour as a 30wt, when the going gets tough, the base oil (pre VII) does matter because that is the weight that is actually lubing the bearing.
Some synthetics will be thinner than the same weight conventional, some will be thicker, some 5W-30's will be thicker/thinner than other 5W or 10W-30's.
You'll REALLY just have to look through the UOA's/VOA's and their websites to find what their viscosities are. This may blow your mind, but Castrol Syntec (aka German Castrol) 0W-30 is probably one of the thickest 30 weights you see.
You'll REALLY just have to look through the UOA's/VOA's and their websites to find what their viscosities are. This may blow your mind, but Castrol Syntec (aka German Castrol) 0W-30 is probably one of the thickest 30 weights you see.
It seems some understand, I wonder save for the oil pump what else in the engine thinks that analog(admit it it's your new favorite word) oil is as thick as the bottle says? Your bearings most likely don't. Syn have less/none of vii's therefore their viscosity is mostly/solely from the base oil, and if you compare a 10w30 syn that's an actual 30wt. to a dino 10w30 that' only a thin 20wt. then I would argue that the syn is thicker in general and really in the bearings.
Originally Posted By: BuickGN
The VII enhanced oil reverts back to it's 10-20wt base oil under pressure in a bearing while a VII-less straight 30wt that is a true 30wt base oil retains it's viscosity. So in reality, even though both pump and pour as a 30wt, when the going gets tough, the base oil (pre VII) does matter because that is the weight that is actually lubing the bearing.
If it reaches the point of shearing and even then, I doubt it shears to a 10 weight. We're not talking about 1980's oils. Besides, syn can shear too.
Hey, if it goes back and forth between the point of shearing, does that make it digital oil?
The VII enhanced oil reverts back to it's 10-20wt base oil under pressure in a bearing while a VII-less straight 30wt that is a true 30wt base oil retains it's viscosity. So in reality, even though both pump and pour as a 30wt, when the going gets tough, the base oil (pre VII) does matter because that is the weight that is actually lubing the bearing.
If it reaches the point of shearing and even then, I doubt it shears to a 10 weight. We're not talking about 1980's oils. Besides, syn can shear too.
Hey, if it goes back and forth between the point of shearing, does that make it digital oil?
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