Mixing Oil Brands - OK or not?

[enzed4]

I have about 4 litres of Castrol Titanium 5W-30 left from my last oil change, and there's a new product (Nulon brand) which is also 5W-30 and LL-04 (it's cheaper). So, in theory, it should be okay to mix them during the next oil change, right?
Can't see why they'd be any different, and it would only be for 2 years until the next oil change.
Any thoughts on doing this?
The Nulon brand is made in Australia, so maybe that should be reason enough to avoid it... :evil: :lol: (just kidding, any Aussie members. No need to cross the ditch and hunt me down )

 

[Grumpyowl]

You only need 2:1/2 litres, got to buy 3 litres I guess.
How much are you going to save ?
I would imagine there's no technical reason why not, but I wouldn't mix oil just to save a few Bob,
anymore than I'd mix brands of tyres.
Only IMO.

 

[mmm-five]

I wouldn't mix oil myself, as you don't know what may conflict in the different formulations.

When was your last oil change - i.e. how old is the 'old' oil?

I use part bottles all the time, but my oil changes are less than 6 months apart.

I wouldn't use an oil that's been in an opened container for 2 years, to save £10. I'd only use it for top ups.

 

[Smartbear]

I have about 4 litres of Castrol Titanium 5W-30 left from my last oil change, and there's a new product (Nulon brand) which is also 5W-30 and LL-04 (it's cheaper). So, in theory, it should be okay to mix them during the next oil change, right?
Can't see why they'd be any different, and it would only be for 2 years until the next oil change.
Any thoughts on doing this?
The Nulon brand is made in Australia, so maybe that should be reason enough to avoid it... :evil: :lol: (just kidding, any Aussie members. No need to cross the ditch and hunt me down )

Should be ok if they're both the same grade, I'd also only mix like with like regarding synthetic/semi-synthetic etc.
I'd be more inclined to change the oil more often than 2 years, plenty of people feel this is far to long for the engines long term health
Regards

 

[Smartbear]

I wouldn't mix oil myself, as you don't know what may conflict in the different formulations.

When was your last oil change - i.e. how old is the 'old' oil?

I use part bottles all the time, but my oil changes are less than 6 months apart.

I wouldn't use an oil that's been in an opened container for 2 years, to save £10. I'd only use it for top ups.

Hi, oil won't go "off" in an opened container, when I worked as a motorbike mechanic we had a bulk oil container in the yard which stored the economy type oil, it didn't get used much so the oil must have been stored for years with no ill effects
Regards

 

[mmm-five]

Hi, oil won't go "off" in an opened container, when I worked as a motorbike mechanic we had a bulk oil container in the yard which stored the economy type oil, it didn't get used much so the oil must have been stored for years with no ill effects
Regards

I was told that opened oil should be replaced when it's 2 years old, as it breaks down a little as it oxidises.

But that was buy someone at OpieOils, so maybe they just wanted me to buy more of the stuff

 

[enzed4]

Thanks for the replies. Last oil change was Oct 2014, so about 16 months (and about 7,000 Km). I will probably look at increasing the changes to 12 months.
Both the 'old' oil and the new are fully synthetic, 5W-30, LL-04, so in theory should be the same.
I might just stick with the Castrol, as any increase in cost (it's about 30% more than the Nulon brand) is more than offset by the savings in labour by doing the oil and filter myself. Engine oil is so critical to the life of the engine it's probably false economy 'bargain hunting' this component. Same goes for the filters, I just buy them from BMW - yes, a bit more expensive but I know I'm getting the correct filter and not having to worry about quality or fit.

 

[Toe-side]

Same grade and spec will be ok. I would not mix types (synthetic, semi or mineral)
Always purchase from known suppliers to prevent counterfeit products