[richardmontgomery]

i want to buy a top up for my 335i 2006 the bmw book recommends castrol but does not state the grade..

do you know thanks

[roadkillrob]

BMW Castrol 5W30 full synthetic - if you can't get that (available from the dealer) you need to find a BMW approved oil which it will say on the bottle - Mobil 1 0W40 is bmw approved and a few others.

[XLR8MF]

Many people have misinformation or opinions that are stated as fact.
Here is some factual evidence to base your decision on. Castrol legally is a synthetic.
Now you ask what does legally mean. There are specific institutions that rate and grade oil throughout the world. Castrol synthec was never a Grade A (the best) or a grade B (also very good) oil. Castrol takes the average oil refining process and then adds additives that themselves are made synthetically. The institutions wanted to NOT allow Castrol the rights to be labled as a TRUE SYNTHETIC but the LIARS, I mean Lawyers, for Castrol took them to court and basically said that since a certain percentage of our oil is made with sythetics it should be allowed to be a synthetic. To make a long story short (too late) they compromised and Castrol Synthec is a GRADE B synthetic motor oil but it will never ever be put in my high performance machine. There are other good after market Grade A synthetics but the Mobil 1 European CAR Formula 0W40 is just about the best GRADE A synthetic their is. I have researched this topic to exhaustion so if you do not believe me then research it yourself but I would suggest you save yourself the time and effort and just use the European formula. I repeat that type because their is a Mobil1 0w40 that is not Euro formula and it is not approved for e90 or e92. Good luck.

[tripDHL]

^ha you typed liars when you meant to say lawyers, that's funny.

[b335i]

Took a quart of sythetic 5w-40 Castrol yesterday! works like a charm. BTW, it even says specifically formulated for BMW MB etc on it. No biggie

[richardmontgomery]

thanks for the help... nice one...