Can you mix engine oil types?

Soldato
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Hey guys, so I have 4 litires of 5w40 of one brand and I want to mix it with mobil 1 5w30 xe.

Are there any negatives to this?

I'm going for an oil change and I figured if I have the 4 litres laying around I may as well use it.
 
Soldato
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I don't think I'd mix synthetic with non-synthetic , but, I don't think you are proposing that, thinking non-synth might break down the synth.
 
Soldato
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There is a video on youtube where someone mixed something like 40 different oils in the same engine and it worked fine :p
 
Caporegime
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Hey guys, so I have 4 litires of 5w40 of one brand and I want to mix it with mobil 1 5w30 xe.

Are there any negatives to this?

I'm going for an oil change and I figured if I have the 4 litres laying around I may as well use it.
What brand ?
 
Soldato
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Modern multigrade oil is a mixture of different oils anyway, so provided you get the correct viscosity it'll be ok, however I wouldn't do it personally because a car engine is usually worth thousands of pounds and for the sake of £40 or so I'd prefer the peace of mind that the correct viscosity is going in.
 
Soldato
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Yeah I don't think there would be any harm from mixing them but thinking about it I'll just use it as a top up instead or grab more on the next oil change. Both weights are fine for my car :)
 
Soldato
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Check owners manual, it usually gives you range of viscosity you can use. If it says use 0w-30 up to e.g 15w50 then yea mix and match as long as you dont go outside the viscosity e.g 0w20 or 10w60 etc, well you could use the last two but need to do some balancing calculations. Lol
 
Soldato
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Two mixed oils are infinitely better than an insufficient quantity of the right oil….
That's my thought, I had to top up my m3 once on the motorway and all the garage had was 0w60 (or 5w60 can't remember) . As there were ~8 litres still in the engine I figured it was worth it, the engine was fine ever 20,000 miles later.
 
Soldato
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That's my thought, I had to top up my m3 once on the motorway and all the garage had was 0w60 (or 5w60 can't remember) . As there were ~8 litres still in the engine I figured it was worth it, the engine was fine ever 20,000 miles later.
Didn't you have to get your engine replaced? :confused::o:p
 
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