Petro vs. Synthetic Based Motor Oils

[sgtfreyday]

Can I switch between petroleum based and synthetic motor oils?

Planed on using synthetic oil during the season but for my year-end maintenance and storage, was just going to slap in some 10W-40, run her for a few minutes then shut it down for hibernation. When spring rolled around, drain the petro. based and fill with the synthetic.

Somebody, some where (it may have been a synthetic oil salesman) said, once you go upgrade, have to stay. Didn’t make much sense.

[fj12dean]

Originally posted by sgtfreyday
Can I switch between petroleum based and synthetic motor oils?

Planed on using synthetic oil during the season but for my year-end maintenance and storage, was just going to slap in some 10W-40, run her for a few minutes then shut it down for hibernation. When spring rolled around, drain the petro. based and fill with the synthetic.

Somebody, some where (it may have been a synthetic oil salesman) said, once you go upgrade, have to stay. Didn’t make much sense.

yes, you can switch.

[XVZ RoadRunner]

Myself I just change to oil to what ever you use normaly.

Of course I store my bikes in a semi-heated garage over the down time. Any moisture that the oil may absorbed over the down time will evaporate the first time you run it at operating temp. for at least 30 minutes. Don’t get me wrong hear it’s not much and the additives are designed to do this.

[Shane]

I have always been told no. I was told that it will cause the clutch plates not to work properly if you go back to the real oil.

[In The Blood]

The Great Oil Debate (http://www.eric-gorr.com/techarticles/mototech_june_1999.htm)

[fj12dean]

cool, an oil discussion...

i've heard from trusted sources that mobil 1 red cap (15w50) as cited in the link by intheblood is the one that's okay for m/c use. i'll admit that i've succumbed to castrol gtx on occasion, but with all the additives (what are they on now, st? sz? ( :), i don't make a habit of it.

these days, i only use castrol when i'm trying to wheelie my shaft drive mc. ( :

[sgtfreyday]

Really never paid that much attention to the stuff until and article in October 7, 2003, Sport Rider ran a lab test on motor oils. Tried finding a link to post on LR.com to no avail. Have hard copy and can list if I get hold of a scanner. Interesting info viscosity, anti wear agents, acid neutralizers, etc.
The fact is most people will probably not fully utilize the stuff considering bike will be sold, rebuilt or trashed before the benefits really kick in…???
If you have a keeper, there is definitely a difference in automotive vs. m/c and synthetics.

[sgtfreyday]

Being I am not a petroleum engineer, thought they may be the appropriate party to ask:


All of Castrol's oils are fully compatible with one other, and there is no
cause for concern if you choose to switch from conventional to synthetic or
vice versa. Because of this, it is not necessary to flush the engine. It
is a common myth that you cannot go back to a conventional motor oil after
using a synthetic.
--Castrol Consumer Relations


One more urban legend debunked.........

[XVZ RoadRunner]

Well, for what it is worth I have always used a MC oil in all my bikes over the years and never had a oil related failure. Most were new bikes some where kept a while and some sold to local people and there were no oil related failure that I know of. I will run them hard at times but I do know where red line is. JM2C

[fj12dean]

Originally posted by sgtfreyday
Being I am not a petroleum engineer, thought they may be the appropriate party to ask:


All of Castrol's oils are fully compatible with one other, and there is no
cause for concern if you choose to switch from conventional to synthetic or
vice versa. Because of this, it is not necessary to flush the engine. It
is a common myth that you cannot go back to a conventional motor oil after
using a synthetic.
--Castrol Consumer Relations

i believe that, as it applies to the engine. these are automotive oils. as shane pointed out, however, i'd be curious how it would apply to clutch life. i've almost 60k on my bike with no ill effects, however.

[sgtfreyday]

The only issue I see with synthetics is that some lines have a high amount of molybdenum which can cause clutch slippage. Some mfg. spec oil with no moly because of the problem. That is all I know of the clutch issue(s).

Just have this old skeleton in the back of my head from a jillion years ago...saying dont mix (think it is) Golden Spec. (a synthetic 2-stroke)with about any other oil because it is synthetic and will gel the fuel. Albeit, this is apples to oranges but it's somewhat along the same lines...

Oil emulsifies oil. How could motor oil gel another oil?

[Motorsports Photo]

Originally posted by sgtfreyday

Oil emulsifies oil. How could motor oil gel another oil?

Texas crude and PA crude are the two bases. They really arent comaptable but do seem to tolerate each other OK.

My take and experience on the dino/synth changeover debate:

Freah motors must have dino oil to break in properly. After the break-in time the switch over to synthetic is good. Switching back to dino oils after using synthetics is fine. Switching to synth oils after using dino oils for an extended period of time is NOT a good thing.

YMMV-

-SP

[Shane]

Now I switched my beat up chevy camaro from dino to syn after 100,000 miles and I credit the mobile-1 for that beat up car making it to 200k miles. For what it is worth.

[fj12dean]

Originally posted by Motorsports Photo
Texas crude and PA crude are the two bases. They really arent My take and experience on the dino/synth changeover debate:

Freah motors must have dino oil to break in properly. After the break-in time the switch over to synthetic is good. Switching back to dino oils after using synthetics is fine. Switching to synth oils after using dino oils for an extended period of time is NOT a good thing.

YMMV-

-SP

you didn't say _why_ it's not a good thing...

[Wheelie Monster]

I've been using Mobil 1 15w50 (red cap) for years now, my R6 has over 26,000 miles on it with no problems, and I run the piss out of her all the time!!! That is all I'm putting in my bikes from now on! The bike also shifts smoother too!