I have some leftover oil Mobil 1 Advanced Fuel Economy 0w30 from another car and was wondering if that is a suitable oil to top off my BMW full sun in one of my current cars. I do not plan to purchase any BMW oil, I got for a reasonable price and have read somewhere that Mobil 1 0w40 was a suitable substitute. I have heard BMW is like a castrol oil or is.. So you don't have to sing and dance about that..
Suitable top off oil for...
- Thread starter iluvhonda
- Start date
- Status
Ow30 into a 5W30 sump is fine from the viscosity angle but I don't like mixing additive chemistries from two completely different oils... not optimal unless you know the details of each additive package. It's not likely to hurt anything, and a severe case is additive clash is almost impossible, yet mixing tends to negate some of the good qualities of each of the oil mixed (unless you picked two that are compatible).
Also RE "Topping Off": Are you adding a cup to bring it up to full or adding a full quart? If it's less than half a quart, it's certainly unnecessary and I would counsel that unless it needs a full quart, don't bother. Oil level varies according to engine temp and it's easy to forget and add too much oil. Overfull isn't good either.
Also, FWIW, if your car uses oil, running it between add and full often reduces perceived oil consumption vs topping off constantly. When you are constantly topping off and keeping it at or above full line, the engine may try to burn off that upper half quart due to more splash onto the cylinder walls, more aeration and vaporization (which can go up the PCV valve) due to being thrashed about by the crankshaft (windage). People who constantly top off seem to have more issues with regular oil consumption that those who add a full quart when it reaches the add mark.
Also RE "Topping Off": Are you adding a cup to bring it up to full or adding a full quart? If it's less than half a quart, it's certainly unnecessary and I would counsel that unless it needs a full quart, don't bother. Oil level varies according to engine temp and it's easy to forget and add too much oil. Overfull isn't good either.
Also, FWIW, if your car uses oil, running it between add and full often reduces perceived oil consumption vs topping off constantly. When you are constantly topping off and keeping it at or above full line, the engine may try to burn off that upper half quart due to more splash onto the cylinder walls, more aeration and vaporization (which can go up the PCV valve) due to being thrashed about by the crankshaft (windage). People who constantly top off seem to have more issues with regular oil consumption that those who add a full quart when it reaches the add mark.
Last edited:
Jim shows a lot of insite in his posts, so I would tend to give him some attention.
I think he's on the mark in this post, both with regard to topping off and chemical compatibility.
Just because you won't see an outright failure when mixing oils of entirely different additive chemistries doesn't mean that you're getting an optimal result.
Apples aren't oranges and M1 is not Euro Castrol with a BMW label.
I think he's on the mark in this post, both with regard to topping off and chemical compatibility.
Just because you won't see an outright failure when mixing oils of entirely different additive chemistries doesn't mean that you're getting an optimal result.
Apples aren't oranges and M1 is not Euro Castrol with a BMW label.
To Jim. Oil topping off happens every week. But for what's its worth. It's an h22 Honda motor..
Originally Posted By: fdcg27
Jim shows a lot of insite in his posts, so I would tend to give him some attention.
I think he's on the mark in this post, both with regard to topping off and chemical compatibility.
Just because you won't see an outright failure when mixing oils of entirely different additive chemistries doesn't mean that you're getting an optimal result.
Apples aren't oranges and M1 is not Euro Castrol with a BMW label.
+2. Also Dr Haas says the exact same thing. While it won't lead to engine failure it isn't necessarily optimal.
Jim shows a lot of insite in his posts, so I would tend to give him some attention.
I think he's on the mark in this post, both with regard to topping off and chemical compatibility.
Just because you won't see an outright failure when mixing oils of entirely different additive chemistries doesn't mean that you're getting an optimal result.
Apples aren't oranges and M1 is not Euro Castrol with a BMW label.
+2. Also Dr Haas says the exact same thing. While it won't lead to engine failure it isn't necessarily optimal.
Originally Posted By: fdcg27
Did you get a real deal on the BMW syn?
Have you seen lower consumption with it?
This is a much higher HTHSV oil than the Honda calls for.
I'm just trying to understand why you selected this oil for this application.
Decent deal, it's rebadged with the mini label.
Did you get a real deal on the BMW syn?
Have you seen lower consumption with it?
This is a much higher HTHSV oil than the Honda calls for.
I'm just trying to understand why you selected this oil for this application.
Decent deal, it's rebadged with the mini label.
Some good advice here, I'm gonna stop topping off and go from there... Just an old habit ive been doing for years. But maybe some h22 guys can chime in...
To Jim again. So topping off I can understand but say its on the below a quart mark. Add or see if it actually consumes oil?
He means that many cars consume much less when people don't keep them full to the gills. I read it that you should let it get low to the point where you can add a full qt. without overfilling it.
Originally Posted By: Coprolite
He means that many cars consume much less when people don't keep them full to the gills. I read it that you should let it get low to the point where you can add a full qt. without overfilling it.
While this might be true, certain vehicles like my 3.0L Aerostar only hold 4.5 qts of oil. I would not want to wait until its down a qt to top off. I generally add top up oil when its down about 10-16 ounces. A low oil level in a small sump when it is very hot out IMO is not a good idea.
He means that many cars consume much less when people don't keep them full to the gills. I read it that you should let it get low to the point where you can add a full qt. without overfilling it.
While this might be true, certain vehicles like my 3.0L Aerostar only hold 4.5 qts of oil. I would not want to wait until its down a qt to top off. I generally add top up oil when its down about 10-16 ounces. A low oil level in a small sump when it is very hot out IMO is not a good idea.
I think demarpaint is on the right track. Top it off and keep it full and don't give it a chance to go below the "needs oil added" line. All engines need good oil and running an engine low is about the worst thing you can do to an engine IMO. Listen to demarpaint.
If I had a car that used oil, I would aim to keep it right below the full mark, avoiding overfill, but not letting it get too close to the add line. In other words, let it go to somewhere between 1/4-1/2(up from the bottom) and then add a 1/2 qt. So that it would be back up near the top mark. This assumes 1 qt separates the two marks.
That is my interpretation of the earlier remarks and avoids overfill problems. Luckily, I haven't had to put this into practice recently.
That is my interpretation of the earlier remarks and avoids overfill problems. Luckily, I haven't had to put this into practice recently.
Well overfill was never a concern but this h22 motor is a "notorious oil consumer, frm cylinder walls and Old school VTEC. So if I saw it was a half quart low I would add. But I also use aftermarket filters with "bigger capacity"
Originally Posted By: iluvhonda
I have some leftover oil Mobil 1 Advanced Fuel Economy 0w30 from another car and was wondering if that is a suitable oil to top off my BMW full sun in one of my current cars. I do not plan to purchase any BMW oil, I got for a reasonable price and have read somewhere that Mobil 1 0w40 was a suitable substitute. I have heard BMW is like a castrol oil or is.. So you don't have to sing and dance about that..
Mobil 1 Advanced Fuel Economy 0w30 would be fine for topping up your Bimmer particularly in the winter. It will marginally lighten up the spec' BMW 5w30 oil which is heavier than necessary for winter use in your climate.
I have some leftover oil Mobil 1 Advanced Fuel Economy 0w30 from another car and was wondering if that is a suitable oil to top off my BMW full sun in one of my current cars. I do not plan to purchase any BMW oil, I got for a reasonable price and have read somewhere that Mobil 1 0w40 was a suitable substitute. I have heard BMW is like a castrol oil or is.. So you don't have to sing and dance about that..
Mobil 1 Advanced Fuel Economy 0w30 would be fine for topping up your Bimmer particularly in the winter. It will marginally lighten up the spec' BMW 5w30 oil which is heavier than necessary for winter use in your climate.
I'll bet if you consult your owners manual, you'll not find a single case where the mfgr recommends adding oil when the level is in the safe zone(anywhere above the add/low mark)... I'll only top off prior if I'm going to be driving enough distance that the level would likely fall below the add mark before I returned home...
Originally Posted By: TFB1
I'll bet if you consult your owners manual, you'll not find a single case where the mfgr recommends adding oil when the level is in the safe zone(anywhere above the add/low mark)... I'll only top off prior if I'm going to be driving enough distance that the level would likely fall below the add mark before I returned home...
Well I was trying to make that a point with a certain motor...
I'll bet if you consult your owners manual, you'll not find a single case where the mfgr recommends adding oil when the level is in the safe zone(anywhere above the add/low mark)... I'll only top off prior if I'm going to be driving enough distance that the level would likely fall below the add mark before I returned home...
Well I was trying to make that a point with a certain motor...
Originally Posted By: TFB1
I'll bet if you consult your owners manual, you'll not find a single case where the mfgr recommends adding oil when the level is in the safe zone(anywhere above the add/low mark)... I'll only top off prior if I'm going to be driving enough distance that the level would likely fall below the add mark before I returned home...
While that might be true, I'm not going to wait until I'm down a qt in my 4.5 qt sump to top it up. Sorry, and this is not an attack on you. But no one is going to convince me that being a qt low is as good as having the oil level at or near the full level.
I'll bet if you consult your owners manual, you'll not find a single case where the mfgr recommends adding oil when the level is in the safe zone(anywhere above the add/low mark)... I'll only top off prior if I'm going to be driving enough distance that the level would likely fall below the add mark before I returned home...
While that might be true, I'm not going to wait until I'm down a qt in my 4.5 qt sump to top it up. Sorry, and this is not an attack on you. But no one is going to convince me that being a qt low is as good as having the oil level at or near the full level.
Last edited:
I thought the study published on the Neptune site pretty well resolved the issue of whether you should top up before you're down a full quart. Those guys found that even small amounts of top up oil had a profound impact on the used oil analysis taken at 1000 mile intervals. TBN numbers jumped significantly with as little as 1/2 qt top up. Since reading their study, I decided to keep the sump full.
So far as mixing oil brands is concerned, my brother in law has a Ph.D. in chemistry and worked in the petro chemical business for years. He told me that if the oil was free, he'd put 4 different oils in his car at oil change time.
So far as mixing oil brands is concerned, my brother in law has a Ph.D. in chemistry and worked in the petro chemical business for years. He told me that if the oil was free, he'd put 4 different oils in his car at oil change time.
- Status