is it ok to mix 0w -30 with 5w -30?

[the_stink]

Ahh I see, cheers for all th replies guys

[danny_p]

the 0 and 5 parts are fine but wtf are you doing putting  /30w oils in it for ?   they are way to thin when hot

[the_stink]

the 0 and 5 parts are fine but wtf are you doing putting  /30w oils in it for ?   they are way to thin when hot

when i ordered it from eurocar parts it was one of the oils it said was for the car, typical stink getting it wrong as usual!! well im going to drain that out ASAP and get the 10/40 in think ill have to see if i can borrow some money from someone broke till 17th and i can only assume the longer the oil is in there its not really going to be doing me or the car any good

[AudiA8Quattro]

the 0 and 5 parts are fine but wtf are you doing putting  /30w oils in it for ?   they are way to thin when hot

Surely it would be worse to have thin oil when the cold? it would probably just fall through the engine.

[Agreeable Slick]

Cold oil = thick oil.

5W30 would have been ok when it was a new engine, but considering age, it needs something a little thicker now.

[the_stink]

well there are no leaks, but im grabing some castrol magnatec 10/40w tonight and going to drain the oil an replace it, also will be getting a replacement oil temp sensor on thurs

[AudiA8Quattro]

Cold oil = thick oil.

5W30 would have been ok when it was a new engine, but considering age, it needs something a little thicker now.

Yes i understand that.
What i meant was when the engine and oil are cold, the tolerances are bigger than when warmed up, so surely a thicker cold oil would be better.
Hence why people use 10w40 instead of 5w40.

[Agreeable Slick]

The numbers on the bottle are like this: first number is when the engine is cold, and the second when the engine is hot. 10w-40 for example the 10 bit means that the oil must have a certain maximum viscosity/flow at low temperature. The lower the "W" number the better the oils cold temperature/cold start performance. The 40 means that the oil must fall within certain viscosity limits at 100 degC, again the lower the number the better the performance at temp.

Basically when the engine and oil are cold two things happen, engine tolerances open up by a nats knacker, and the oil becomes thicker (read molecules move closer together) so that it cannot pass through the micron thick gaps that open up.

[AudiA8Quattro]

Well put there Mr.Slick.
But still an old engine will use more oil when warming up, is this not true?
After disconnecting the breather on an old polo i think this must be true, the volume of blow by was much greater when the engine was cold.
Even though oil is thicker when cold, surely this is when you will lose the oil?
Like i said already, this is why people use 10w40 instead of 5w40.
I think we are probably saying the same thing in a roundabout way.

[Len]

well there are no leaks, but im grabing some castrol magnatec 10/40w tonight and going to drain the oil an replace it, also will be getting a replacement oil temp sensor on thurs

Good choice!