Synthetic oil versus standard oil, same source (crude oil)

[R1150Rclean]

So I have heard talk about synthetic oil causing leaks, and that may be true, but synthetic oil is a mineral oil (i.e., from crude oil). The difference between synthetic oil and regular oil is that they refined synthetic more to remove hydrocarbons (that is why it costs more). The hydrocarbons in regular oil burn and cause the oil to break down faster. Remember when Mobil 1 first came out and they had a commercial with Mobil 1 and a regular oil in frying pans? When they turned on the heat the Mobil 1 stayed clear and the regular oil turned into a black sludge (i.e., it burned). That was due to the hydrocarbons burning.

The name "synthetic oil" is just sales hype , though it does protect your engine way better than regular oil

[The Meromorph]

Group 4 and group 5 oils (PAO and Esters respectively) are not made from crude oil.

Group 3 oils are made from crude oil. Note that made from. The generic technical term for the manufacturing process is 'severe hydrocracking'.

Groups 3, 4, and five are all 'synthetic' in that they are made, i.e. the molecules that constitute them are constructed by breaking apart and reconstructing other molecules. That is the definition of 'synthetic.

Group 2 oil is refined from crude oil, then some of the undesirable molecules left are modified (processed) (Group 2) or some of the molecules are reconstructed (Group 2+).

Group 1 oil is simply refined from crude oil. It is often called 'brightstock'.

Synthetic oils have different heat tolerances (Flash Points and Volatility). These were the differences Mobil was attempting to demonstrate to an uninformed public. They are still the main reason that engine manufacturers will specify the use of synthetic oil (to handle excessive hotspots within an engine, without oil breakdown). For example, the Corvette engine specifies synthetic oil because testing reveal that under extreme conditions, the oil would break down, and there was nowhere to put an oil cooler at that stage of the design, it was cheaper and simpler to simply specify the use of synthetic oil.

The difference in costs (to the oil company is due to the cost of the feedstock for the Group 4 and 5 oils, and the higher cost of manufacturing over refining). The difference is cost for the Group 3 synthetics is due to the additional manufacturing only. It is also much smaller than the difference in cost for Group 4 and Group 5 oils.

[R1150Rclean]

Group 4 and group 5 oils (PAO and Esters respectively) are not made from crude oil.

Group 3 oils are made from crude oil. Note that made from. The generic technical term for the manufacturing process is 'severe hydrocracking'.

Groups 3, 4, and five are all 'synthetic' in that they are made, i.e. the molecules that constitute them are constructed by breaking apart and reconstructing other molecules. That is the definition of 'synthetic.

Group 2 oil is refined from crude oil, then some of the undesirable molecules left are modified (processed) (Group 2) or some of the molecules are reconstructed (Group 2+).

Group 1 oil is simply refined from crude oil. It is often called 'brightstock'.

Synthetic oils have different heat tolerances (Flash Points and Volatility). These were the differences Mobil was attempting to demonstrate to an uninformed public. They are still the main reason that engine manufacturers will specify the use of synthetic oil (to handle excessive hotspots within an engine, without oil breakdown). For example, the Corvette engine specifies synthetic oil because testing reveal that under extreme conditions, the oil would break down, and there was nowhere to put an oil cooler at that stage of the design, it was cheaper and simpler to simply specify the use of synthetic oil.

The difference in costs (to the oil company is due to the cost of the feedstock for the Group 4 and 5 oils, and the higher cost of manufacturing over refining). The difference is cost for the Group 3 synthetics is due to the additional manufacturing only. It is also much smaller than the difference in cost for Group 4 and Group 5 oils.

Like I said, synthetic oils are made from crude oil as you point out above for group 3 (from crude oil paragraph 1, and also considered synthetic paragraph 2). The main point being that the hydrocarbons are removed from synthetic oil, THAT is what causes regular oil to break down!

If chemists had to actually synthesize oil from scratch it would be too expensive for anyone to buy! if you break a bike chain into three pieces is it now a synthetic bike chain?, no it is just a broken chain.

[Beemeridian]

23

[popsnicker]

My understanding is the Mobil1 EP is what Mobil1 was before the Castrol lawsuit.

[ebincia]

My understanding is the Mobil1 EP is what Mobil1 was before the Castrol lawsuit.

Now I'm really confused. So is the castrol 10w50 really a synthetic?

[Beemeridian]

22

[iowabeakster]

Synthetic wigs are made from standard hair wigs. The only difference is that the follicles have been processed by a hydro polymerization technique that neutralizes the need for adhesives.

[combustor777]

What about Motorex 10w-60? Thats gotta be a group 4/5 right?

[boxermania]

The bottom line is:

If you perform your oil changes as recomended by the OEM the dino oil is as good as the synthetic. If you require longer change intervals and additional heat breakdown potential go with the synthetic.

The following link will give you a general overview

http://www.carbibles.com/engineoil_bible.html

[ebincia]

OMG another oil thread that ends with the same conclusion "oil is oil." [SARCASM]

[Beemeridian]

22

[sweatmark]

So I have heard talk about synthetic oil causing leaks, and that may be true, but synthetic oil is a mineral oil (i.e., from crude oil). The difference between synthetic oil and regular oil is that they refined synthetic more to remove hydrocarbons (that is why it costs more). The hydrocarbons in regular oil burn and cause the oil to break down faster. Remember when Mobil 1 first came out and they had a commercial with Mobil 1 and a regular oil in frying pans? When they turned on the heat the Mobil 1 stayed clear and the regular oil turned into a black sludge (i.e., it burned). That was due to the hydrocarbons burning.

The name "synthetic oil" is just sales hype , though it does protect your engine way better than regular oil

Unwilling to walk into an argument here. But would like to respond to original post, based on the training I received at Mobil Oil when working as lubrication engineer in the 1980s (I've worked in a different technical field for the past 20 years):

1. It's not true that "synthetic oil is a mineral oil". The chemistry used for true synthesized lubricant base stocks is more likely derived from esters (alcohols+acids) and/or natural gas. The origin of synthetic lubricant development came from R&D into non-petroleum-based fluids that would function as viscous lubricants, with improved high temperature performance capability. The Wikipedia citation seems to agree with my old Mobil Oil training manual:
http://en.wikipedia.org/wiki/Synthetic_oil
(Note the explanation of term "synthetic" being applied to Class 3 petroleum-based oils in the US only.)

2. If crude oil in its natural form was sufficiently slippery, then we'd have just poured it into motors all these years to keep parts from wearing out:

Come and listen to a story about a man named Jed
A poor mountaineer, barely kept his family fed,
Then one day he was shootin at some food,
And up through the ground came a bubblin' crude.

Oil that is, black gold, Texas tea.

Straight from ground to gearbox would have been so simple. Problem is that the slippery "oily" components found within crude oil (and not just any crude oil) comprise a small portion of the crude, and thus refining/separation is required to extract the good stuff for lubricant use. Refining technology has made big strides over the century, resulting in these "Class 3" base stocks that are derived from crude petroleum and have high purity and performance... and cost more to make than older, "cruder" (excuse the pun) methods.

3. That Mobil 1 frying pan commercial harkens from the days when Mobil 1 and its Mobil industrial lubricant cousins (my former field of work) were produced using Chevron's poly-alpha-olefin (PAO) synthetic lubricant basestock. Yes, the old engine oil that turned black in the frying pan was indeed burnt hydrocarbons. The bright & shiny Mobil 1 in the other frying pan was in fact unburnt hydrocarbons.

PAO turns out to be a great hydrocarbon chemical for lubrication use because of its chemical and temperature stability, and because it's a viscous fluid within a very wide range of temperatures that correlate nicely with typical operating conditions for machinery :: if PAO - like many other hydrocarbon chemical compounds - was a solid or gas under such conditions, then it would obviously not have been a candidate for synthetic lubricant applications.

I became a big believer in PAO-based lubricants as a result of my Mobil work. There are some select lubrication applications that absolutely work best with a PAO. It's possible to exceed the temperature exposure limits of PAO though, and under such conditions another synthetic lubricant chemistry must be used; that's where ester-based materials often find a fit. The old adage about synthetic lubes and leak problems seems to have originated with the use of esters and seal material incompatibility (there are many other "theories" about this connection).

4. FWIW - I don't use PAO crankcase lubes in my motorcycles. I'm too cheap, and the applications don't benefit from ultra tough lubricant technology... it's better to just change oil more frequently. For Rockster and Buell, I use commercial diesel crankcase oil (e.g. Mobil Delvac 1300 Super, Shell Rotella T) available in gallon jugs at WalMart. The Rockster gets Mobil 1 "synthetic" gear lube for transmission and final drive. The Buell's gearbox/primary gets the H-D oil as specified for good wet clutch operation... with long-term oil changes. For my wife's F800 I use the specified BMW engine/transmission oil just to keep my favorite local BMW dealer in business.