WTA: mixing engine oil with different viscocity and/or brand

[e46_UDM]

Dear Sifu,Would like to get some feedback regarding the mixing of engine oil with different viscocity and/or brand during top up. Currently I'm using X brand fully syn 5W 30 and it's required top up. Assumed that I can't get the same engine oil. What is the damage (if any) or will it upset the engine if I:[1] top up from Y brand fully syn but same viscocity (i.e. 5W 30) engine oil.[2] top up from X brand fully syn but different viscocity (e.g. 5W 40) engine oil.If mixed with the sme amount of engine oil but different viscocity, will the viscocity been average out i.e. 5W 30 + 5W 40 = 5W 35? Hope to get some feedback and apologises for asking a rather naive question. Thx in advance.

 

[B33mEr]

Shouldn't be any problem ... you can safely mix different viscosity of oil ----> for topping up purposes only until you get to the next oil change interval.

It's the same thing as well as question no.1 ... Whether it will average out i'm not too sure on this.

 

[manjit]

The first number is never a concern(its the corresponding winter value), you should heed the second number which in your case, is 30, using 40 would not give any problem though.

 

[astroboy]

I'm running Castrol Edge 0w-40 and Torco 5w-30 now at 93:7 ratio.. just because I trust B33mEr.. :4:

 

[e46_UDM]

I'm running Castrol Edge 0w-40 and Torco 5w-30 now at 93:7 ratio.. just because I trust B33mEr.. :4:

any particular reason for this? Mind to explain a bit or should I ask B33mEr instead? Thx.

 

[astroboy]

Haha.. Because N46B20 requires 4.25L. So I pour the whole bottle of 4L Castrol Edge 0w-40, and add 0.3L of Torco 5w-30 which was bought one oil change ago, just for topping purposes..

So 0.3L liter of Torco = 0.3/4.3 = 7%

Haha.. :4:

 

[aidilj]

Haha.. Because N46B20 requires 4.25L. So I pour the whole bottle of 4L Castrol Edge 0w-40, and add 0.3L of Torco 5w-30 which was bought one oil change ago, just for topping purposes..

So 0.3L liter of Torco = 0.3/4.3 = 7%

Haha.. :4:

This is exactly the issue e46_udm is facing and his engine is n42

 

[erica34]

i remember reading at some mobil site Q&A or something of that nature, no problem mixing mobil 1 of different viscosity. it was a while back when i managed to get a 4L bottle of mobil 1 cheap, looked on the internet and decided since mobil themselves say no problem, has to be ok.

 

[e46_UDM]

Haha.. Because N46B20 requires 4.25L. So I pour the whole bottle of 4L Castrol Edge 0w-40, and add 0.3L of Torco 5w-30 which was bought one oil change ago, just for topping purposes..

So 0.3L liter of Torco = 0.3/4.3 = 7%

Haha.. :4:

i.c. this is exactly what am facing at the moment... serviced my N42 last week using Petronas 3000 5W 30 LL (4 liter), then when comes to topping up the balance of 0.25 liter, I can't find any 5W 30 LL in the market even from my regular spare part shop as they ran out of supply... Petronas stations only carry 5W 40. So, with no other choice, I top up the remaining 7% with Petronas 3000 5W 40. It seems that the 3000 5W 30 LL is quite rare in the market... where can I get one? Need to spare some for the topping up of 1 liter every 3K (no leak at the engine, btw)

 

[B33mEr]

i.c. this is exactly what am facing at the moment... serviced my N42 last week using Petronas 3000 5W 30 LL (4 liter), then when comes to topping up the balance of 0.25 liter, I can't find any 5W 30 LL in the market even from my regular spare part shop as they ran out of supply... Petronas stations only carry 5W 40. So, with no other choice, I top up the remaining 7% with Petronas 3000 5W 40. It seems that the 3000 5W 30 LL is quite rare in the market... where can I get one? Need to spare some for the topping up of 1 liter every 3K (no leak at the engine, btw)

I'd suggest you try using 5W-40 or 15W50 and then see how's your oil consumption.

 

[turbology]

Yes to what B33mEr said.
There are more than just the viscosity of the oil were changed when you mixing it, it also affect HTHS, Sulfated Ash, base number and flash point.
Flash point decide how fast your motor oil vapourized when is hot. So you need to check your engine oil regularly.
High viscosity will, sometimes, increase oil consumption too. Thus checking oil consumption, and logging it down is great practise.

Different oil company use different stuff/mineral/chemical in the motor oil. Which mean, mixing different oil in same brand is usually ok & safe.
I won't recommend mixing different brand, unless absolutely a must.

Nowadays, newer engine recommend lower viscosity oil because 1. better technology = less friction. 2. help to reduce oil consumption. Not much, maybe 1% at max per tank of fuel.
But when calculate at a bigger scale, that's few thousand of gasoline are saved in the world per day. (And a better image of car company -> greener. And to meet US fuel regulations (CAFE http://en.wikipedia.org/wiki/Corporate_Average_Fuel_Economy)

But that's sacrifice for engine protection, especially when I rev alot and drive it hard almost everytime. Thus for my preference, 40weight is the minimum I will go.

Hope this help