synth vs. dino

[Dnyce]

why cant you go back to dino after u go full synth? no smartass answers like why would you wana go back, etc etc. everyone says once you switch, you cant switch back. why the hell not? never got a straight answer. some oils are semi synth....im not changing oils-but i like knowing how shit works.

[marko138]

I had heard that years ago...but I'm told now it isn't a big deal if you get all the old Synth out first.

[Trip]

it has something to do with mineral oil coating being thicker than synthetic and the tolerances your engine develops running synthetic.

[6doublefive321]

I would think you can, as long as you do a good flush out. That is, drain the syth, fill up with dino, run for a few minutes. Drain and repeat. Its hard for me to believe that what little synth is left could damage your engine.

Speaking of which, what about "semi-synthetic" oils? What's the difference between having a little synth left over and using a semi-synth oil? Maybe there are some stabilizers in play to eliminate any incompatibilities?

[t-homo]

I use a "parasynthetc" or blended oil. They say if I ever run low and need to get some, I can get conventional and add to it but not synthetic. Don't really know why.

[Amber Lamps]

I got this from Mobile1's website,


Can different synthetic motor oils be mixed together?

Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. However, it is important to note that the superior performance of Mobil 1 will be reduced by diluting it in any way.

They also dispute the need to breakin a motor using dino and the need to flush a motor before using synth. There wasn't any mention of flushing before going back to dino. Altho',I don't get why you'd want to flush out the good stuff before putting in the cheap crap. That'd be like making sure you rinse your glass before switching from Grey Goose to Heaven Hill!

Originally Posted by Trip

it has something to do with mineral oil coating being thicker than synthetic and the tolerances your engine develops running synthetic.

Um doesn't viscosity determine an oil's "thickness" and if so wouldn't ANY 10W40 oil be the same? I always thought the "superiority" of synth was it's ability to retain it's viscosity for longer under harsher conditions.

[Trip]

Originally Posted by TIGGER

Um doesn't viscosity determine an oil's "thickness" and if so wouldn't ANY 10W40 oil be the same? I always thought the "superiority" of synth was it's ability to retain it's viscosity for longer under harsher conditions.

Not the viscosity of the oil, the thickness of the coating on the parts they are lubricating.

Parts getting use to running with a thinner gap than is required with dino lubricants, where dino runs at a larger gap.

[Amber Lamps]

Originally Posted by Trip

Not the viscosity of the oil, the thickness of the coating on the parts they are lubricating.

Parts getting use to running with a thinner gap than is required with dino lubricants, where dino runs at a larger gap.

hmmm...so you're saying that your oil can determine how far apart the metal parts in your engine operate from one another and that synth oil puts a "thinner" coating on metal parts than dino oil does? I always thought that the tolerances in your motor are what they are,minus wear ofcourse,and your oil can't affect that other than by allowing wear. For the most part,internal components are surrounded by oil,so the gap is always going to be the same no matter what you run. How can you increase the gap on one side of a part without reducing the gap on the other side? Unless you are stating that dino oil "compresses" parts,making them smaller,thus allowing for a larger gap all the way around.

Anyway,I've checked a couple of other websites and they all state in their faqs that it's ok to run/mix synth with conventional oil and to change back and forth at will.

[Amber Lamps]

Repsol;
- Can two lubricants be mixed in the same engine?

All lubricants on the market (whether petrol or diesel engines, mineral or synthetic) can be intermixed. Nonetheless, mixing two different quality oils reduces the overall quality.

- What is the difference between a synthetic and a mineral lubricant?

A mineral lubricant is made up of a base obtained directly from oil distillation plus some additives which improve its performance.

With a synthetic lubricant, the bases are treated through a physical/chemical process in order to obtain a higher quality and performance. With semi-synthetic lubricants, mineral and synthetic are combined.

- Are synthetic lubricants the best?

Yes. Synthetic lubricants have been specially created to respond to the demands of the engine or to be used in extreme temperatures and very intense service conditions.•

Castrol;
Can I switch between a synthetic and a conventional oil?
It is a common myth that you cannot go back to a conventional motor oil after using a synthetic. All of Castrol's oils are fully compatible with one another, and there is no cause for concern if you choose to switch from conventional to synthetic or vice versa. Another common myth is that you cannot switch from a conventional oil to a synthetic oil without first flushing your engine. If you currently use conventional oil, you do not have to flush your engine before you switch to Castrol SYNTEC.


Valvoline;The Aging Standard
Conventional motor oil has been the benchmark in engine lubrication since Carl Benz invented the car in the late 1800s. Over the years, oil manufacturers have improved the refining processes to remove impurities. Still, mineral-based oil, even in its most pure form, remains somewhat imperfect.
This liquid lubricant performs two primary functions inside your engine. It reduces friction between moving parts, and it dissipates heat created by the combustion process. At normal operating temperatures, conventional oil protects the internal workings of your engine. This ability to protect as well, however, when engine temperatures rise or fall below the norm (as you would find upon start up, during spirited driving or in extreme climates) is limited because at lower temperatures conventional oil becomes thick, or more viscous. (NOTE,vicous=thick,Tig) In this state it may have difficulty reaching critical components. At higher temperatures, the same oil often becomes too thin to adequately coat and effectively protect moving parts.
Synthetic oil, on the other hand, has a higher tolerance for temperature extremes, thereby maintaining a more consistent viscosity. This means your engine is better protected overall regardless of engine operating temperatures.
Size Does Matter
Synthetic oil is also more resistant to thermal and oxidative breakdown, processes that occur when oil is exposed to the severe conditions inside an engine. When motor oil begins to break down, it is essentially burned away, which causes it to lose its ability to protect valuable engine parts and dissipate heat.
The reason for synthetic oil's increased resilience stems from its uniform molecular structure. Conventional base oil is composed of several sizes and shapes of hydrocarbon molecules. This variation brings with it a range of evaporation, oxygenation, and burn points. Included in the mixture are some comparatively unstable molecules, some of which break down very soon after the conventional oil is poured into your car. This forces the remaining oil to work harder.
To overcome the problem of thermal and oxidative breakdown, synthetic base oils are created through a series of chemical synthesis. The starting materials may be a mixture of relatively pure small molecules. In this case the small molecules are combined to make new, larger molecules. Alternatively the starting material may be a broad mixture of larger molecules. In this case the large molecules are broken down and rearranged. The result is motor oil that is composed solely of pre-selected similarly sized molecules devoid of any weak links that inhibit performance. The new molecules are specifically shaped to offer optimum lubrication and maximum resistance to thermal breakdown.

Anyway,that's just a few of the sites I got from a google search.

[Trip]

Originally Posted by TIGGER

hmmm...so you're saying that your oil can determine how far apart the metal parts in your engine operate from one another and that synth oil puts a "thinner" coating on metal parts than dino oil does? I always thought that the tolerances in your motor are what they are,minus wear ofcourse,and your oil can't affect that other than by allowing wear. For the most part,internal components are surrounded by oil,so the gap is always going to be the same no matter what you run. How can you increase the gap on one side of a part without reducing the gap on the other side? Unless you are stating that dino oil "compresses" parts,making them smaller,thus allowing for a larger gap all the way around.

Anyway,I've checked a couple of other websites and they all state in their faqs that it's ok to run/mix synth with conventional oil and to change back and forth at will.

The matter in between moving parts can determine the tolerances as wear sets in because they are a factor in the wearing process. This may not be something of concern at all in a motorcycle engine, it may have stemmed from an engine that's tolerances are a lot more unforgivening. I am just simply stating what I have heard for why you aren't suppose to change back and it may be something that isn't even a concern for these engines. Instead of being completely unhelpful to this topic, why don't you try researching why this notion was started that you can't go from syn to dino.