I have recently found out that Nelson used Semi-Synthetic Castrol Magatec Oil 0/40W on my last service. :mad:

 

I have some Castrol RS 10W60 (fully synthetic) which I intend to replace it with.

 

Question: Can I do a straight oil change, or will I need to flush it first?

 

Mike

Yes,no flush needed;)

Indded, u cud even mix the 2 with no problems.;)

Would it make semi semi synthetic? ;)

Originally posted by pete shrimp

Would it make semi semi synthetic? ;)

 

No I think it would be Fully Semi Synthetic. :D

Cheers, I'll just do an oil change then.

 

Wish me luck, it's my first time, on any car! :D

 

Mike

Originally posted by pete shrimp

Would it make semi semi synthetic? ;)

 

LOL!:D

 

Most oils are safe to mix (with the exeption of engine/cooking oil/baby oil.....etc).

But the general rule is if your using fully synthetic oil, and you add semi synthetic, it will degade the fully down to semi synthetic, same as if you added mineral to fully or semi it would degrade that down to mineral.

 

There are odd exceptions to this rule but any oil which wont mix with another will have it written on the pack.

 

Thus if you are running on semi, there is no point topping up with fully as you will gain nothing from it.

 

But on complete oil changes the tiny pockets of old semi left in the engine wont be enough to degrade your new oil.

 

And seeing as your changing the oil, no problem.

 

So why am i rambling!!!:x:

If you want to do a proper job, run the engine with

flushing oil for about 20 mins with old filter in place.

 

Drain that then fit new filter and fill with the new oil.

 

Think that 40 is a bit low for the Z engine, am I right?

lower quality oils degrade faster and don't lubricate as well (don't think that's much though) - it's mainly that they degrade faster and leave more much ih the engine. A mix of good and bad wll simply be better than the bad alone and worse than the good alone. better oils usually alos have more and better additives to reduce degradation and mop up crap from the engine.

 

http://www.chris-longhurst.com/carbibles/engineoil_bible.html

A word of warning on this subject, if your car has only ever been run on non/semi synthetic oil, and you then use a flushing oil followed by using fully synthetic oil, you might find your engine starts to leak from various points, the higher the mileage the higher the risk of this.

 

Although not on my zed, I flushed and changed to fully synthetic on my last Audi with about 80K miles when I got it. Prior to this, there was not a trace of oil on or below the engine. Following though... within a week or so of normal use, everything started to oil up, especially around the rear engine to transmission area (crank seal) and I wished I'd not flushed it!!

 

This can happen because slight deposits built up over time around worn engine seals and actually stop any leaking with no real harm to your engine, suddenly, these are aggresively removed by a flushing oil, followed by a more viscous synthetic oil which finds it easier to make its way out of the engine seals.

 

I would personally not flush it, and run on a semi synthetic with frequent changes (3000miles), but then I don't drive the car hard, so maybe you'll be better with fully syn. just be aware of the above thats all!!

 

OK thats my twopence worth

 

Paul N

 

:) :)

That'll be me 'not flushing' then.

 

Mike

I think even fully synthetic is still semi synthetic! Does'nt make sense I know.

 

Mines is high mileage, been used to semi all its life and has been flushed once as well. Since I've had it its been using Castrol RS 0-40. Supposedly full synthetic. No problems no leaks.

No I think it would be Fully Semi Synthetic

 

I'd have thought equal quantities of semi-synthetic mixed with fully synthetic would give three-quarter synthetic ?

Originally posted by Herman Munster

That'll be me 'not flushing' then.

 

Mike

 

Typical bloke. LOL

Originally posted by zevans

Typical bloke. LOL

 

I'm gonna leave the seat up too :D

 

Mike

A P*ss on it too I hope.....

from what I have read, fully synthetic (Like mobil 1 and castrol RS) is still only a modified mineral oil, and not synthetic at all. True synthetic is very expensive and cannot be mixed with any form of the "so called" fully or semi synthetics

 

 

John

That maybe why Castrol will normally charge you over £40 for RS10-60?

Paid £30 for mine :D

 

Mike

.........and its still only modified mineral, sounds like a bit of a con.

 

 

John

Im not telling you how much I paid for mine, but it was cheaper ;)

Yes I know someone, can't remember who, can get it cheaper, but he's going on holiday.

 

Selfish git :D

 

Mike