blending different oil grades?

[320touring]

So the iS is overdue an oil change...

The book oil for the car is 10w40 semi synth-local supermarket had some castrol going cheap,so I now have enough 10w40 for 3 changes I may purchase more..

Question is this-could I 'blend' in some 5w30 to make it a bit thinner?

Just thinking it may be better being thinner in the cold weather we have..

[gone-ot]

...yes, you can "do it," but, no, it won't make the oil 'thinner' overall.

[320touring]

Originally Posted by Old Tele man

...yes, you can "do it," but, no, it won't make the oil 'thinner' overall.

Thanks,exactly the answer I was looking for...

Guess i'll just plough more cash into the 10w40 as its 1/2price

[mwebb]

using 10w40IF AND I REPEAT IF it is approved by BMW for your application is the way to go

but
more important than the viscosity values are the BMW oil specifications which are applicable for that car/engine .
BMW LL01 afaik
so a off the shelf 10w40 semi synthetic is NOT acceptable and
there are many if not all oils that meet BMW LL01 that are not 10w40
ALL OF THEM ARE FULL SYNTHETIC and meet the
ACEA A3 B3 - A3 B4 specification as well as the BMW LL01 specification

i would contact BMW direct
OR
look in the BITOG forum in the European section to clarify exactly what the minimum oil specification for your car really is and never use an oil that does not meet that specification .

and

mortals who are not lubrication engineers should never "blend oils"
unless they are salad oils for salads only
unless

unless you enjoy pain and internal engine work on older BMW engines

Originally Posted by 320touring

So the iS is overdue an oil change...

The book oil for the car is 10w40 semi synth-local supermarket had some castrol going cheap,so I now have enough 10w40 for 3 changes I may purchase more..

Question is this-could I 'blend' in some 5w30 to make it a bit thinner?

Just thinking it may be better being thinner in the cold weather we have..

[320touring]

Originally Posted by mwebb

using 10w40IF AND I REPEAT IFit is approved by BMW for your application is the way to go
but
more important than the viscosity values are the BMW oil specifications which are applicable for that car/engine .
BMW LL01 afaik
so a off the shelf 10w40 semi synthetic is NOT acceptable and
there are many if not all oils that meet BMW LL01 that are not 10w40
ALL OF THEM ARE FULL SYNTHETIC and meet the
ACEA A3 B3 - A3 B4 specification as well as the BMW LL01 specification
i would contact BMW direct
OR
look in the BITOG forum in the European section to clarify exactly what the minimum oil specification for your car really is and never use an oil that does not meet that specification .

The oil meets the relevant standards as required by the owners manual.

and

mortals who are not lubrication engineers should never "blend oils"
unless they are salad oils for salads only
unless

unless you enjoy pain and internal engine work on older BMW engines

Old Tele man's response indicated that already,so i honestly don't see what your response adds to this thread.thanks for dropping by, in your whacky blue way,but I feel I've got the answer i needed after one post.

[jakobnev]

If you want thinner for cold weather 5w-40 is what you should look for.
Motor Oil Viscosity Grades Explained in Layman's Terms

We have full synth 5w-40 API SM/CF, ACEA A3/B3/B4 for £5.60/L here.

[320touring]

Originally Posted by jakobnev

If you want thinner for cold weather 5w-40 is what you should look for.
Motor Oil Viscosity Grades Explained in Layman's Terms

We have full synth 5w-40 API SM/CF, ACEA A3/B3/B4 for £5.60/L here.

Thanks for the recommendation!

Will see what I can find over here

[mwebb]

the oils referred to in the owners manual
no longer exist
which is a good thing
the BMW specifications have been upgraded to reflect current lubricants

spend a wee bit of time in the BITOG forum
study and learn
it does not hurt
your engines will thank you

Originally Posted by 320touring

The oil meets the relevant standards as required by the owners manual.



Old Tele man's response indicated that already,so i honestly don't see what your response adds to this thread.thanks for dropping by, in your whacky blue way,but I feel I've got the answer i needed after one post.