• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

Rationale for not mixing brands of oils in the same oil change?

N

ncpbmw1953

Member
Assuming API, JASO and SAE weight spec are the same, both synthetic, can you think of a valid reason not to mix a couple of quarts of each in an oil change? I don't know where I got this idea but presumably from reading an opinion somewhere or other. I have a couple of quarts of Brand A so tempted to mix it 50:50 w/ Brand B.
 
ncpbmw1953 said:
Assuming API, JASO and SAE weight spec are the same, both synthetic, can you think of a valid reason not to mix a couple of quarts of each in an oil change? I don't know where I got this idea but presumably from reading an opinion somewhere or other. I have a couple of quarts of Brand A so tempted to mix it 50:50 w/ Brand B.
Click to expand...

Well, as BMW owners, we should only be using BMW-Branded Oil in our Teutonic Steeds. Therefore, we should never be in a position to mix different oils. Similar to how the mechanic at my local BMW Dealership only puts air imported from Germany in my tires.




My feeble attempt to stir the pot.
 
The chemistry of the oil is not going to necessarily mix as thought. They take time to blend oils in the lab and mixing oils affect the fact doesn't accomplish the blending. I suspect it's OK to do this just to get to the next oil change, but I wouldn't do it as a matter of course. I would just buy the best oil I could get.
 
Nope, no issue.

1. does it meet spec?
2. Does it meet your budget?
3. Mix away!

Also remember any oil is better than no oil so if you don't see your spec in a auto store and you're on a long trip, just grab your recommended weight and put it in, .5L out of spec but within weight oil to get oil back in the sight glass is better than running low.
 
There was a time when there was a danger of additive packages from different brands not being compatible, but in the last 30 years or more, as long as all the designators are the same you shouldn't have any problem.
 
I don't see the overall point. My position is that oil is one of the most critical maintenance items in the bike. Get the best quality oil you can find, change it religiously, and motor on down the road. Why take the chance that it might work? Ask a branded petroleum engineer and I don't think he'll tell you it's OK to mix...the line from them is to use their product or a given product by itself. I'm not sure where you would find out other than on a long duration test stand. There are proprietary products in an oil blend.
 
20774 said:
I don't see the overall point. My position is that oil is one of the most critical maintenance items in the bike. Get the best quality oil you can find, change it religiously, and motor on down the road. Why take the chance that it might work? Ask a branded petroleum engineer and I don't think he'll tell you it's OK to mix...the line from them is to use their product or a given product by itself. I'm not sure where you would find out other than on a long duration test stand. There are proprietary products in an oil blend.
Click to expand...

To me, the issue becomes what to do on a trip. Assume using BMW's latest and greatest Advantec. And here I am is West Misletoe, Wyoming and need to add oil. Am I supposed to detour 400 miles to a dealer to buy Advantec ; have a dealer ship me some oil; haul oil with me; or add a different brand of in-spec oil? I have not had an oil burner lately so the issue hasn't arisen, but in the earlier days of my R1150R this would have been a valid issue.

I do know what I would do but as for everybody else, their bike, their choice.
 
I might have read something into the original post. I didn't feel it was an "on the road" situation, but rather "hey, I found two oils at home and want to mix them". Given that the OP was talking about a precise 50:50 mix, that seemed the most likely. Paul, I do agree that you do what you have to on the road...you probably wouldn't be able to control the mixture so precisely.
 
Once or twice around the galleries at 70 or 80 psi is going to mix whatever you put in there into a one homogeneous lubricant. If the different oils going in meet spec then the combined lubricants will meet spec.

Nothing like a high pressure trochoidal oil pump spinning 3,500 rpm to turn strangers into friends.
 
PGlaves said:
To me, the issue becomes what to do on a trip. Assume using BMW's latest and greatest Advantec. And here I am is West Misletoe, Wyoming and need to add oil. Am I supposed to detour 400 miles to a dealer to buy Advantec ; have a dealer ship me some oil; haul oil with me; or add a different brand of in-spec oil? I have not had an oil burner lately so the issue hasn't arisen, but in the earlier days of my R1150R this would have been a valid issue.

I do know what I would do but as for everybody else, their bike, their choice.
Click to expand...

This was how I took the question, as well. After all, if you're someplace buying oil for a planned change, why would you be thinking of mixing it? That wouldn't make sense, to me anyway.
 
I doubt there would be an issue mixing them, but why take the chance if you don't need too? But a couple more quarts of each so you have enough for a complete change.

That said, while traveling would not worry about it. I had a Harley that was burning oil. (don't blame Harley, it was a self inflicted issue!) I was coming home on the trip and have about four different brands in the crankcase before I got home. I was concerned that my buddy that was riding with me was going to have an aneurism! Especially when I dumped in a quart of 5W-30 on top of the assorted 20W-50 oils that were in there already. Hey, it got me home!
 
Stebe said:
This was how I took the question, as well. After all, if you're someplace buying oil for a planned change, why would you be thinking of mixing it? That wouldn't make sense, to me anyway.
Click to expand...

Too many bikes with different requirements and a lot of different but similar brands and weights single quarts left sitting around? Not that I would know anything about that...
 
The OP was clearly talking about an oil change, not adding oil on a road trip. He also talked about having a couple of quarts of oil on hand.
 
You must log in or register to reply here.

Similar threads

V
2012 K1600 GTL Oil Change Question....mixed weights and types...
Replies
7
Views
2K
boogerman
boogerman
G
New (to me) K1300GT owner
Replies
5
Views
1K
HSVPhil
HSVPhil
senseamidmadness
Tiny metal flakes on the drain plug -- should I be worried about my transmission?
2 3 4
Replies
74
Views
17K
senseamidmadness
senseamidmadness
gtgt_bangbang
Dances with Snowflakes; My Rear Wheel Hidden Balancer Story
Replies
5
Views
757
pauls1150
pauls1150
D
F-Twins Tech – F650/700/800 - Engine Oil Change with Filter
Replies
11
Views
7K
drneo66
D
Back
Top