Engine Oil: what's best?

[Shepherd]

A 4th possibility is that your mechanic accidentally put in used oil.

If you are saying the oil he put in was darker after 50km than the Nulon after 7000km, that seems to be the most likely explanation.

One oil shouldn't clean out the engine so much better than another.

[KWAWD]

A 4th possibility is that your mechanic accidentally put in used oil.

If you are saying the oil he put in was darker after 50km than the Nulon after 7000km, that seems to be the most likely explanation.

No way I believe that happened.
Maybe I should try and describe it better:
On the dipstick it looks dark, like dark honey, but not jet black like old oil does.
In the drainage container it all looks very black, you couldn’t shine a light through it for instance.

The Nulon, OTOH, looks a light golden colour and translucent.

Maybe some cheaper oils are just dark from new.

[Shepherd]

I found the Safety Data Sheet for Magnatec Professional A5 5W-30. It describes the colour as "dark brown", so it seems that it is unusually dark.

[KWAWD]

I found the Safety Data Sheet for Magnatec Professional A5 5W-30. It describes the colour as "dark brown", so it seems that it is unusually dark.

Thank you Shepherd! That must explain it. Stuff is ugly thats for sure.

[leadfoot6]

I found the Safety Data Sheet for Magnatec Professional A5 5W-30. It describes the colour as "dark brown", so it seems that it is unusually dark.

Personally, I would be very surprised if any oil manufacturer/retailer attempted to market any engine oil that could be described either visually or in words as being "dark brown".

Checking both of the data sheets in this link( both in page 5 of 9 of the respective documents under "Appearance" - "Colour" ):

https://msdspds.castrol.com/msdspds/...edmb=No&cols=0

A5 https://msdspds.castrol.com/ussds/amersdsf.nsf/Files/E197FFA34267F52F802583930057F6EF/$File/11445843.pdf

C3 https://msdspds.castrol.com/ussds/amersdsf.nsf/Files/49468C44EC50286B8025828F0052B4FE/$File/11350908.pdf

only referred to "brown".....not "dark brown".

@Shepherd, you were possibly looking at a different data sheet to the ones I found for this type of oil?

The reason that I would be very surprised is that most customers of mine(or of other salesmen) seeking to purchase a used car, would at some point check the appearance of the engine oil via the dipstick.....unless the used car industry has undergone very significant changes since I retired a number of years ago.

Many would not pass a comment about oil that appeared transparent or generally of a lighter shade of brown.

To them, it was how they perceive that it should be.

If it was dark, they are generally quick to remark that "this oil is old"..... "the car needs servicing"....."didn't you just say that the car has been recently serviced in your workshop?" or similar comments.

(often, this is a bargaining tactic used to attempt to force the price down aka "objections")

If I told them that "yes, this car has been workshop serviced, but the oil they use is "dark brown", my credibility would instantly disappear.....leading to much reduced chance of a sale.

No.

An oil manufacturer or retailer would be asking for customer backlash by attempting to convince customers, either home mechanics or workshops, that a dark coloured oil straight out of the container was the "norm".

P.S. I looked at 3 different sources for reviews of this product, totaling some 20 reviews, and not one made mention that the oil appeared "dark".

If it were indeed so, I would have expected at least one reviewer to pass a comment about it's appearance.

P.P.S. Another data sheet:

https://cdn.opieoils.co.uk/msds/cast...nalA55w-30.pdf

provides the description of appearance as "Amber"....."Light".

See section 9.1 on page 6 of 10

9.1 Information on basic physical and chemical properties
Appearance

Physical state Liquid

Colour Amber. [Light]
[.....]

That is how I would perceive any passenger car petrol engine oil fresh out of the container to be.

As stated above, I would be very surprised if it were otherwise.

[Shepherd]

The Safety Data Sheet I found was for Magnatec Professional supplied by BP Singapore (which would be what we get) whereas the SDS showing the colour as light amber is for oil supplied by Castrol UK - so there could be a difference in colour (though I agree that dark brown would be an odd choice). The other 2 SDSs are for Magnatec Stop-Start.
I should add that the SDS for the Singapore oil is dated November 2010, so it might not be current. Also I don't know if its the correct grade.