Lubricants for high mileage 535i

[Unregistered]

Prior owner put in Chevron 20/50 to avoid leaks, but never bothered to tighten oil pan bolts, which were all finger tight. Bolts are now tight, and engine clean, with no signs so far of external leaks.

Car has ~240,000 miles and good engine compression, good automatic tranny, and good differential.

What engine oil (including synthetic) is best for this engine?

Redline for tranny and differential?

[Mark Hillenbrand]

I have had great luck with Mobile 1 (I also ran Amsoil until they came out with the o-40 Mobile 1). I run 0-40 in my 150K miles 525i, If it's not too hot you might want to start with that.

Conventional oil is too expensive to run.....every 3K miles plus a filter and disposal....no way. With Mobile 1 or other reasonable synthetic, you can extend your oil changes and add a quart and a filter along the way if 5 to 10 K oil changes bother you...

[Warren N.CA]

for the diff, RedLine 75W90 or 75W90NS, as appropriate.

As for the tranny, if you are not sure when and with what it was last changed (if it was changed), I would suggest investigating and considering VERY carefully before you do anything at all.



Prior owner put in Chevron 20/50 to avoid leaks, but never bothered to tighten oil pan bolts, which were all finger tight. Bolts are now tight, and engine clean, with no signs so far of external leaks.

Car has ~240,000 miles and good engine compression, good automatic tranny, and good differential.

What engine oil (including synthetic) is best for this engine?

Redline for tranny and differential?