Fred W writes:
<OK, I don't get it... Why do you *not* trust BMW engineers to tell
when to change the transmission and diff oils (never), but trust them
completely when it comes to the engine oil? >
The problem with this statement is not that I don't trust BMW
engineers, I do, but that I don't trust BMW "marketing." Every since
BMW went to "free" maintenance, its fluid changes have either been
extended or become "lifetime."
For example, BMW previously recommended that coolant be changed, of
course using *only* BMW coolant, every 2 years. That now has been
extended to 4 years. In the US, BMW coolant is Valvoline Zerex G 48,
its composition has not changed since 6/03, yet the recommended change
interval is now longer.
Similarly, BMW use to recommend that tranny and differential fluids be
changed every 30K. Now, its NEVER! Sorry, I still change those fluids
every 30K. Note, the 30K fluid change is for MANUAL transmission. Its
my understanding that BMW automatic trans fluid is very expensive and a
longer interval may be adequate.
As for engine oil, I still use dino oil in my 1990 E34 535i, 5 speed,
105K miles. I change oil and filter every 3-4K.
I normally use Redline fluids. However, my last tranny & differential
fluid change was with Royal Purple. I figure for $6-7/quart, its not
too expensive. So far, I have about 3k-4K on RP and at least for the
tranny, the shifting seems fine. We will see. If not, its back to