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Johnboy65

Mixing Oil viscosities?

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Apologies in advance if this topic has already been covered.

My F10 is due an oil change. Last one I did, I used Castrol Edge 0w-30.

Having bought too much I still have approx. 2.5 litres left over.

 

My dilema is this. I've managed to source Castrol Magnatec 5w-30 at almost one quarter the price of the forementioned Castrol Edge!

Both oils are BMW LL 04. Both are Fully Synthetic. Both Castrol.

 

Would you recomend mixing roughly 50:50 ?

Will my engine explode? No seriously will it make any difference?

 

Thanks in advance!

 

magnatec.jpg

Edge.jpg

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This is a difficult one but the 0w and 5w measures are only important when the oil temperature is at or below a certain level ( can’t remember what that threshold is) both act exactly the same once the engine is warmed up. Both are also approved grades by BMW. Would I mix them, for a few 10s of pounds - no. But as I’ve mentioned I’m anal about this stuff. 

 

Is is your car going to explode? No. And you probably will never notice any difference. I can’t imagine there will be any negative impact on the engine. Maybe they will act together and give you 2.5w30??

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Buy more 5W-30 LL04, enough to do the change.

 

Don't buy too much of this stuff other wise you will be in the same boat next time around. I would be inclined not to mix it as you have the opportunity to put all of the same stuff in at the right time. Use the left over 0W-30 as top up.

 

I'm sure I've read in a BMW handbook that incase of a need to top up you can mix the viscosities. It will do no harm, both oils are LL04, some oil is better than no oil or low oil!

 

If you have the N47 variant you want to be anal about the frequency of oil changes. Max 10k miles or 12 months whichever comes first to keep the chains sounding sweet. To be honest you should do that no matter what the engine is as it helps keep the turbo bearings in good nick too.

 

If you buy oil in 4l bottles you will always have some left as these engines (4 and 6 pots) use about 6 to 6.5 L at a time I'm guessing this is what you did with the 0W-30? It's a bit of a pain.  My E60 used 8L at a time which meant none left for top ups and I had to buy a single litre (at higher cost) just for top ups.

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28 minutes ago, bmwmike said:

It's not subjective it's science.  Look at the chart I posted. Unless you plan on driving at lower than -32.5c..

Your chart is showing what the numbers on the pack of the oil tin do.   Not what happens when you Mix the oil.

 

Please provide a paper or scientific document that tells us that mixing of oil has no detriment to either of the oils being mixed and then we can claim its science ;) 

 

I am sure these companies spend millions to formulate their oils over long periods of time just to be proven that they can mix it with any old stuff and it does exactly the same thing :D

 

I would not advise anyone to mix oil for the sake of a few quid :)

Edited by Enzo503

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14 minutes ago, Enzo503 said:

 

Your chart is showing what the numbers on the pack of the oil tin do.   Not what happens when you Mix the oil.

 

Please provide a paper or scientific document that tells us that mixing of oil has no detriment to either of the oils being mixed and then we can claim its science ;) 

 

I am sure these companies spend millions to formulate their oils over long periods of time just to be proven that they can mix it with any old stuff and it does exactly the same thing :D

 

 

Do not mix your oil unless as a last resort it is for top up purposes and the original oil is coming to the end of its cycle/useful life.

 

 

Ah the old "show evidence". Thought it was past bedtime.

 

https://www.opieoils.co.uk/t-new-faq.aspx

 

Check out the "is it ok to mix oils".

 

If you still don't believe it IDGAF. The fact is mixing oils of same type is fine and the net effect is the 5w mixed with 0w means you get something like 2.5w because it's a BLEND. Which funny enough is what most of the oil packers do.. they blend oils.

 

Do what you like at the end of the day but don't pull the "show me the link or you're lying" type BS because it's tedious. Google.

 

 

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A webstore that sells oil saying its ok to mix oils does not change my mind on the matter.

 

Edit:  I am no expert, I would like to learn.  From the research I have done though, it is not advised to mix oils.  Now if there is something that shows otherwise great but I have yet to find it.

If you have this evidence that it is ok, I would like to read it.     But don't get all butt hurt because I have questioned your "its science" quote.  

Edited by Enzo503

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18 minutes ago, Enzo503 said:

A webstore that sells oil saying its ok to mix oils does not change my mind on the matter.

 

Edit:  I am no expert, I would like to learn.  From the research I have done though, it is not advised to mix oils.  Now if there is something that shows otherwise great but I have yet to find it.

If you have this evidence that it is ok, I would like to read it.     But don't get all butt hurt because I have questioned your "its science" quote.  

 

I'm not butt hurt LOL. What is that anyway?  Oh on second thoughts don't tell me... :wacko:

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Cheers Guy!

I think if we start a Brexit and an oil combo thread, then we'll have great fun. 

 

On a serious note, I can agree with both of you.

On one hand Mike makes sense as the oils are practically identical. Both BMW LL 04 & both FULLY synthetic. I will not be track driving, just very moderate everyday use. Also I will not be driving in extreme weather conditions, eg Alaska or Siberia. Therefore it shouldn't make any difference to me. I will end up with something like a 2.5w-30 grade oil.

 

Then we have Enzo who introduces (quite rightly) a large dollop of doubt. ie we do NOT know with 100% certainty how the chemicals/additives in these 2 oils will interact. They may not interact at all. The interaction might be totally benign. But it might be very negative, and damage my engine!

 

I will be saving/losing approx 25 quids worth of 0w Edge, to take that risk.

I'm still :unsure:

Edited by Johnboy65

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If it panics you don't do it. Send the oil to me and I'll have it LOL

 

Not worth the stress is it.

 

(Would 100% be fine tho!)

 

Edit to add are you sure that magnatec is OK for your engine In the first place ?

 

Edited by bmwmike

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26 minutes ago, bmwmike said:

If it panics you don't do it. Send the oil to me and I'll have it LOL

 

Not worth the stress is it.

 

(Would 100% be fine tho!)

 

 

Fair point. Like most things in life, if it keeps you awake, then probably best to avoid.

PS the 0w-30 is in the post!

 

Edited by Johnboy65

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8 hours ago, Johnboy65 said:

Wow! I never thought oil could be so involved, interesting or contentious. 

 

 

Did I not tell you discussing oil on here is always interesting? Lol:D

 

8 hours ago, bmwmike said:

 

 

Edit to add are you sure that magnatec is OK for your engine In the first place ?

 

 

That's a good point as it never used to be LL04. Possibly as oils have improved over the years, Castrol Magnatec might now meet the spec of LL04.

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I only use Mobil1 0W-40 have run it in all my cars some for mega miles, Only Oil i have used where I can thrash car from cold without worrying about the engine.

Edited by NeilV535
spelling

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6 hours ago, 535i Andrew said:

 

Did I not tell you discussing oil on here is always interesting? Lol:D

 

 

That's a good point as it never used to be LL04. Possibly as oils have improved over the years, Castrol Magnatec might now meet the spec of LL04.

 

Indeed. Well I've ordered it from Halfords. The website states (as does the bottle image) it's BMW LL04. If it's not on the bottle when I go to collect, then I wont be having it

 

 

magnatecback.thumb.jpg.58ab3b9efb7f2180e9b9e0d19e7160a7.jpg

Edited by Johnboy65

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16 hours ago, 000000000000 said:

 

Your chart is showing what the numbers on the pack of the oil tin do.   Not what happens when you Mix the oil.

 

Please provide a paper or scientific document that tells us that mixing of oil has no detriment to either of the oils being mixed and then we can claim its science ;) 

 

I am sure these companies spend millions to formulate their oils over long periods of time just to be proven that they can mix it with any old stuff and it does exactly the same thing :D

 

I would not advise anyone to mix oil for the sake of a few quid :)

 

One  point I want to dispute with Enzo. He said and I am mixing "any old stuff". Clearly that is not what I'm proposing. These oils appear to be very similar, albeit the Edge will have better performance on start-up at extremely low temps.

 

One thing I cant figure though, is why the huge price difference? Is it just marketing, or is there a real and substantive difference between the 2? Why is Magnatec always so much cheaper?

 

I actually might mix a small bottle of the 2 oils 50:50 and put it in my freezer (along with a sample of the 2 unmixed oils) overnight and see how their viscosity is affected, if at all

Edited by Johnboy65

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Castrol Magnatec with out being offensive is any old stuff.

Have you seen the demo's for magnatec oil with all its clinging properties.    So you mix normal castrol edge with it, what happens to those clinging properties of the magnatec.  Does ALL of the oil now cling like it did with just magnatec?  does none of it now cling because its been diluted?   or worst of all does the magnatec cling and the edge not causing separation? 

 

"I'm no scientist, but I actually might mix a small bottle of the 2 oils 50:50 and put the my freezer (along with a sample of the 2 unmixed oils) overnight and see how their viscosity is affected if at all "

Its not about what happens when the oils are cold, there is a reason why its advised you should not rev your engine until everything is warmed up. 

 

There is also a reason why when I finish building one of my racing engines I spend the money to run it in on a decent mineral oil before moving to an old favorite Slick 50 or castrol R (which strictly cannot be mixed full stop) or similar oil.

 

Like everything else, these oils are tested in set situations in a lab,  up to 100c for example.  After 100c these formulations may do completely different things.    A modern bmw diesel if doing an active regen will get quite hot in the turbo.    I am not expert enough to say what happens to the oil but I would not want some concoction of cheap oils in there.  Sure it maybe ok and your engine is not going to blow up now.    But in 20k/40k miles time will there be bearing issues where the oil is starting to separate and your getting differing cooling and thinning properties.  What about your  20d and its sensitive Timing chain tensioner? 

  If 1 oil breaks down at 110c and the second breaks down at 120c, you think the mix will give you a break down point of 115c?  

These are all extreme examples but this is what you pay your money for, to save you money if something goes wrong and something goes extreme.   A blocked dpf maybe?   what temps do you get then?     You still want your self mixed oils in your engine?

 

For someone to advise yeah its fine mix your oils nothing will happen in fact it will "blend"""Which funny enough is what most of the oil packers do""    is just insane.  

 

Its like saying you can mix your run flats with your standard tyres, radials with your crossply's.  The car is still going to drive but should anyone advise it? Well google says its ok so...…..  

 

 

edit: If anyone has legitimate proof that all the oils are the same and they break down the same and they do the same thing as long as your within spec, please post it.   It will save me lots of money and I can just go and buy my oil from asda.

 

 

Edited by 000000000000

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Hi all apologies if ive been a little on the abrasive side or upset anyone's belief system here.  

 

Hopefully we can all agree that the best course of action always is to do what you feel is best. Ask the Internet a question and you'll get many answers. Who knows. Maybe the OPs engine will turn to mush or seize up if these two oils are combined. Somehow I doubt it. I also left wondering what a dealer would do in such a situation.

 

Have a good day. Peace out :P

 

 

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