Hi all - I have a 2010 Mercedes GLK350 with the 3.5L V6 port injected motor. Engine is running great at 110k miles and consumes very little oil over it's 10k/1yr oil change interval. It has had a steady diet of M1 0w-40 and Mahle filters over it's life. I was thinking of switching to Liqui Moly from FCP Euro to take advantage of their lifetime warranty program. I have some Mobil 1 0w-40, Castrol 5w-40 laying around. Can I mix that up with some Liqui Moly and run it for my next 10k? Everything is MB229.5 approved.
Mix up all my leftovers for my next oil change
- Thread starter randomhero439
- Start date
Once it’s mixed it’s not MB 229.5 approved because MB hasn’t tested that mixture.
It will probably be OK, but it’s probably not worth the minor risk, when it’s easy enough to buy the correct oil. Save it for a beater or top-ups.
It will probably be OK, but it’s probably not worth the minor risk, when it’s easy enough to buy the correct oil. Save it for a beater or top-ups.
It will do 10k and you won't notice much downsides, but if you run a UOA, that mix will be at or very close to the end of it's life. While either of those oils by itself will still have plenty of life left in same interval. That said - I'd run it for 5k without thinking twice about it.
Edit: I agree with @SR5 above, it won't exactly be a 229.5 oil anymore. But it will be perfectly fine with plenty of safety margin at @5k mark.
Edit: I agree with @SR5 above, it won't exactly be a 229.5 oil anymore. But it will be perfectly fine with plenty of safety margin at @5k mark.
Some Mobil1 and a dash of Castrol constitutes, "all my leftovers"?
Yeah, not the best Frankenbrew, but go for it!
gathermewool
Site Donor 2023
I see no reason why you can’t. Why would the sum of the constituents be lesser than any individual? Sounds absurd. I bet your next 10k analysis would look just fine. I’d bet on it.
Yes, mix and use to your hearts content.
I used to mix ALL weights of oil back in the day. If I could still change my own oil today I would still mix.
I used to mix ALL weights of oil back in the day. If I could still change my own oil today I would still mix.
While the oils are compatible, they never completely mix if different brands are mixed (like Mobil + Castrol). As result it never becomes a super duper w40 that has the best of both worlds, but instead it stays as two weakened w40 oils that work side by side in the same crankcase. Therefore a 5k OCI would be wiser on a mix, while 10k is perfectly doable by either of the oils on its own.
gathermewool
Site Donor 2023
I don’t agree with that. Why won’t they mix?
Thanks! It seems most of you would feel comfortable running it 5,000 miles (1/2 the normal OCI). I'll do just that.
Some additive as zinc need to be above a certain level to work at all. Some newer oils do not use zinc. So if you mix the two then that purposed additive of each of the mixed oils are only there at half of the needed concentrations. Many oils are said to be compatible, that is they can be mixed. That does not mean they will work as intended when concentrations of numerous additives are cut in half. I never mix oils.
Ali
Ali
Sounds like all the oil OP is mixing is Eurocar A3/B4 stuff that should have around 1000ppm of phos, even then all S rated PCMOs should have at least 600ppm of phos, the only oil I know of that doesn't have any phos is Chevron Delo 600 ADF but that's only CK-4 rated and probably some ACEA E sequences and related manufacturer specs for HD diesel engines.
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They are all similar in Zinc content
for no scientific reason whatsoever and based on absolutely no data, i only use leftover mixed oils in my beater. no frankenbrews in my good stuff.
Yep.
wemay
Site Donor 2023
I used to frown on mixing but have come to realize that any danger stemming from this is less than what could happen to you sitting at a stop light. Life is too short to worry if a one off mix is going to harm my vehicle.
My Mother had a Suuzuki Jimmny from 2013 to March this year. It had nothing other than yearly frankenbrew changes. Whatever I had on the shelf from 20w50's to 0w20's. Some fills were literally lots of 500ml dribbs and drabs from different bottles.
Engine was spotless and running perfect (including the VVT system) when she told it with 40k on the clock.
Engine was spotless and running perfect (including the VVT system) when she told it with 40k on the clock.
I would use that mix for your normal oci
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