Synthetic Oil

[Bobingabout]

I have "Acquired" some synthetic 15/40 oil, marked "For use in Diesel Engines".
My engine has always been run on "Real" 15/40 oil (For diesels).
Does anyone know if I can safely replace the normal oil with synthetic, without any ill effects? (Bearing in mind it's not possible to remove 100% of the old oil, especially when pumping it out through the dipstick hole, as I do).

 

[tome]

I asked my VP agent this question and was told that it's ok to put in synthetic BUT that you then have to use the stuff always, and can't go back to ordinary oil.

I didn't bother

 

[rich]

I was told by sabre to run on the oil that the engine was first tested on,,,do not change spec,,

rich )

 

[Guest]

Rather depends upon your engine. If its an older type, e.g. Perkins 6354, BMC 1.5 and so on then you could end up glazing the bores if you use to high-tec an oil. Look at the API rating on the can (usually small letters somewhere) If it says API CF or API CG or the like then the oil will be too slippery for an older type engine but perhaps perfect for a turbo Volvo. If it says API CC or API CD then its probably fine for an old plodder, not so good for a high tec high stress screamer.

 

[vyv_cox]

Perfect advice from the bargee. Your synthetic will almost certainly be a high performance oil, no point in the expense otherwise, with an API grade of CG or maybe more. Its TBN (base number) may be as high as 15, whereas the TBN of a CD is about 3. So in use, the oil will remain basic instead of neutral, which is the intention. Basic oils give several problems, one of which is an increased tendency for bore polishing.

 

[Guest]

Do not mix the two

If you put synthetic in and theres standard base oil still there it is possible to sludge up. Flushing before change is advised with appropriate flushing oil based on oil changing TO>

Basically I would stick to cheap base oil instead of tempting gods with synthetic ......