Help me understand (synthetic no better than dino?

[zerosoma]

Looks like in this article, synthetic has absolutely no advantage over conventional oil in flow properties.

What I'm getting from this article is you can run a conventional oil and a synthetic oil in the same engine and you're going to get the same wear on the top piston bearing. It seems the only advantage synthetic has over conventional is that it has extra additive to protect once the oil passes the hydrodynamic and mixed film stages.

If so, why do they say synthetic "flows" better in cold weather? If, according to this article, they both have the same flow properties, then what is the deal with this claim?

http://www.bobistheoilguy.com/effects-of-shearing/

 

[CourierDriver]

Originally Posted By: zerosoma
Looks like in this article, synthetic has absolutely no advantage over conventional oil in flow properties.

What I'm getting from this article is you can run a conventional oil and a synthetic oil in the same engine and you're going to get the same wear on the top piston bearing. It seems the only advantage synthetic has over conventional is that it has extra additive to protect once the oil passes the hydrodynamic and mixed film stages.

If so, why do they say synthetic "flows" better in cold weather? If, according to this article, they both have the same flow properties, then what is the deal with this claim?

try this at bob main page, tons of data on your inquiry
http://www.bobistheoilguy.com/motor-oil-101/
http://www.bobistheoilguy.com/effects-of-shearing/

 

[Ken2]

First, motor oil is a mixture of base oil and an additive package. The base oil can be from any of five groups, or mixtures of these groups, as long as the finished product meets the spec on the package label. Here are the groups:
Group I base stocks contain less than 90 percent saturates and/or greater than 0.03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.

Group II base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.

Group III base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have viscosity index greater than or equal to 120.

Group IV base stocks are polyalphaolefins (PAO).
Group V base stocks include all other base stocks not included in groups I, II, III or IV.
Base oils in Group III, Group IV, and Group V have the legal right to be marketed as "synthetic." That is a marketing term, not necessarily a technical term.

The additive package contains antiwear agents, antioxidants, antifoamants, anticorrosives, friction modifiers, pour point depressants, viscosity index improvers, dye, etc.

Your point about the type of wear shown is for the need for antiwear agents to handle boundary lubrication when either the hydrodynamic film of oil hasn't yet formed or has broken down due to excessive force. The strength of the oil film is mainly dependent on the viscosity of the oil, although PAO base oil has a slightly higher film strength. I am not suggesting that a higher viscosity oil will let your engine live longer...ordinary 5w30 oil in many modern engines works fine for the first 300,000 miles or so. Use whatever oil viscosity the engine maker designed the engine to use.

The Group III, IV, and V base oils with their inherently higher viscosity index do flow somewhat better when cold and thin somewhat less when hot without the addition of non-lubricating chemicals for the depression of the pour point and viscosity index improvers to thicken them when hot.

So-called synthetic oils do perform better under extreme circumstances. Conventional oil performs fine under normal circumstances. For the best protection when very cold, very hot, or extended drain intervals, synthetics work better longer.

 

[Garak]

Originally Posted By: zerosoma
If so, why do they say synthetic "flows" better in cold weather? If, according to this article, they both have the same flow properties, then what is the deal with this claim?


In addition to what Ken said, synthetics also provide more viscosity options. There's no guarantee that a 5w30 conventional will flow worse than a 5w30 synthetic. However, the synthetic can be had in grades like 0w-30, too.

 

[friendly_jacek]

I haven't seen a proof that synthetic fluids decrease wear, except for extremely cold starts. That's where the SAE 0W comes in.

There are also other benefits: cleanliness, long OCI, high temp resistance, etc.

 

[fdcg27]

Synthetic labeled oils do offer a higher VI and typically better cold starting characteristics.
Check the PDSs for the numbers on cold start, which most give, as well as VI, which most give.
The typical OTS synthetic is not a whole lot more expensive than the typical conventional.
Consider also that synthetic labeled oils are often heavily promoted, so between deal pricing and MIRs, they can be quite cheap to use.
Are they no better?
I think they are.
It might be more useful to think of them as the premium oils in each blender's product line, since there really isn't any bright line distiction between the two.
I know that some like to discuss basestocks, but none of us really know what blend of basestocks are used in formulating any given oil. We really know only a little of the additives used as well. We never see those that aren't metallic.

 

[zerosoma]

Originally Posted By: CourierDriver

try this at bob main page, tons of data on your inquiry
http://www.bobistheoilguy.com/motor-oil-101/


OK, different question in the same vein...so apparently it doesn't matter what viscosity you use as it is all flowing at the same rate at operating temp (212*F). So technically since I drive highway a lot, if I were to put say, 10w40 Royal Purple in my car this winter at an average outside ambient temp of 10*F (article says ambient temp no longer matters in motor oils), it shouldn't matter as long as I let the car warm up first before taking off.

Am I reading into this right?

 

[zerosoma]

Originally Posted By: Ken2


The Group III, IV, and V base oils with their inherently higher viscosity index do flow somewhat better when cold and thin somewhat less when hot without the addition of non-lubricating chemicals for the depression of the pour point and viscosity index improvers to thicken them when hot.



This article posted above says the following :

"More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. It would be more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this is the problem."

So according to this oil does not thin when it gets hot. Right?

 

[Quattro Pete]

Originally Posted By: zerosoma
OK, different question in the same vein...so apparently it doesn't matter what viscosity you use as it is all flowing at the same rate at operating temp (212*F). So technically since I drive highway a lot, if I were to put say, 10w40 Royal Purple in my car this winter at an average outside ambient temp of 10*F (article says ambient temp no longer matters in motor oils), it shouldn't matter as long as I let the car warm up first before taking off.

But it does matter because you can't skip the entire warm up process and start right at around 212F if the engine was shut off for a few hours before. If you compare 10w-40 to 0w-40, the 0w-40 will always flow better at cold startup and therefore result in less wear. Remember, most wear occurs at cold startup, regardless if you let it sit in your garage/driveway to warm up or if you start driving right away. And the lower the startup temp, the more pronounced the difference between the two oils will be.

 

[Nodak]

Great topic men!! I'm learning a lot reading the responses. Keep it going - I too, like zerosoma, have been curious about this.
I've got a car that has been running mostly Valvoline conventional, Havoline and a little Quaker State Conventional all of it's life and it has over 205,000 miles on it. It sits outside, even in the winter,and starts like a champ and runs like a champ. (I do plug it in once and a while).In other words-straight dino all the time and it seems to run well and uses very little oil. I use synthetic in my other vehicles, but does it really matter? Man! it does get cold up here.!!

______________________
97 Prk. Ave.-5-30 Havoline and Wix filter
03 Corolla-5-30 Quaker State Ultimate Durability and Wix filter
04 Rav 4 Mobil 1 High Mileage 5w30 and Wix filter

 

[KrisZ]

Originally Posted By: zerosoma

This article posted above says the following :

"More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. It would be more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this is the problem."

So according to this oil does not thin when it gets hot. Right?


Absolutely wrong. You should read that quote again, very carefully.

 

[Quattro Pete]

Originally Posted By: zerosoma
So according to this oil does not thin when it gets hot. Right?

Wrong. You misunderstood. It does thin, but that's not the problem. The problem is that it thickens as it cools, and that's why we have things like 0w-XX grades available to help minimize the problem.

 

[RamFan]

Think of it this way. Synthetic and conventional oil will flow the same at operating temperature. However, when the oil is at ambient temp let's use 50*F, the synthetic will remain less thick than its conventional equivalent. It's during the ambient to operational temperature phase that a synthetic is superior to conventional in terms of fluidity.

 

[Garak]

Originally Posted By: Quattro Pete
It does thin, but that's not the problem. The problem is that it thickens as it cools, and that's why we have things like 0w-XX grades available to help minimize the problem.


Exactly. Maybe to aid comprehension of the readers, there's no problem with how thin the proper viscosity oil is at temperatures - it's supposed to be that way. One wants to limit how thick it gets when it cools to the ambient temperatures. A 0w-40, 5w-40, 15w40, and straight 40 will all be of similar thickness at operating temperatures. The differences appear when the oil cools down, and I have started vehicles unaided in -40 C with a 0w-40. I wouldn't want to try that with a straight 40.

If they could come up with an oil that maintained the same viscosity at -40 C and at 100 C, then there would be no issue.

 

[zerosoma]

Originally Posted By: Quattro Pete
Originally Posted By: zerosoma
So according to this oil does not thin when it gets hot. Right?

Wrong. You misunderstood. It does thin, but that's not the problem. The problem is that it thickens as it cools, and that's why we have things like 0w-XX grades available to help minimize the problem.


Ok, thank you, that was much more helpful than KrisZ's response.

 

[zerosoma]

Originally Posted By: RamFan
Think of it this way. Synthetic and conventional oil will flow the same at operating temperature. However, when the oil is at ambient temp let's use 50*F, the synthetic will remain less thick than its conventional equivalent. It's during the ambient to operational temperature phase that a synthetic is superior to conventional in terms of fluidity.


Can anyone tell me then, from the Motor oil 101 article, what this quote means? :

"One thing that is no longer important is the ambient temperature."

I mean obviously if we follow the owner's manual there shouldn't be a problem, but I'm curious as to how things work (as I'm sure a lot of you are) and I'm just trying to comprehend how this stuff works. Thanks!

 

[RamFan]

Once the engine is at operating temperature the ambient temperature does not matter. Once operating temperature has been achieved the oil will remain at that temperature, plus or minus a few degrees. Also please remember, the "feels like" temperature does not affect oil at all! If its 30* out but feels like 10*, you're oil will be affected by the 30* ambient temperature only.

 

[ueberooo]

IMO the biggest advantages of synthetic over dino is that synthetic is more durable and has better viscosity as function of temperature. Dino on the other hand has superior ability for solvency, i.e. soaks up the dirt very well.

How often is the piston bearing the first to go? Intuitively it seem like there'd be much less movement and wear on the piston bearing than the crankshaft bearings.

I've always been more worried about cylinder and piston wall and crankshaft bearing wear. Intuitively and IMO, crankshaft bearing would be more to worry about than piston bearing because you see more movement there (it's where the torque gets transferred to crankshaft); though I suppose the piston bearing could get lots possibly considerable up-down vibrations/forces if you like to over-rev your engine .

 

[Coprolite]

Originally Posted By: zerosoma

Can anyone tell me then, from the Motor oil 101 article, what this quote means? :

"One thing that is no longer important is the ambient temperature."

I mean obviously if we follow the owner's manual there shouldn't be a problem, but I'm curious as to how things work (as I'm sure a lot of you are) and I'm just trying to comprehend how this stuff works. Thanks!


In addition to what was noted above, ambient temperatures of 110 degf has no impact on the oil. Many people consider this severe service. It is severe service for the air conditioning and the cooling system, but not the oil. If anything, the oil will reach operating temperature slightly faster and remain there for those who have oil coolers.

A cold ambient temperature will cause the oil to remain below optimal viscosity, impacting fuel economy and making it necessary for the driver to drive with a lighter foot until it is warm. As already noted, the biggest problem is when the oil is too thick, not too thin. Higher VI and 0w oils will have lower comparative viscosity at these temperatures, making them fractionally better.

The biggest advantage of syn is probably the ability for extended drains. If you are changing often, the additional cost is only worth it if you like an additional safety factor.

 

[Quattro Pete]

Originally Posted By: zerosoma
Can anyone tell me then, from the Motor oil 101 article, what this quote means? :

"One thing that is no longer important is the ambient temperature."

What I think he also meant by this is that the ambient temp no longer matters when it comes to oil selection. Another words, if you choose an oil such as 0w30 or 0w-40, this oil will provide the best protection money can buy regardless if you use it in the dead of winter in Alaska or in the summer heat of Arizona.

Back in the day, some owner manuals used to recommend different oil grades for different ambient operating conditions. That was before we had shear stable multigrade synthetic oils. Nowadays, the same oil can provide the best of both worlds year round.