The M62 engine in my X did the first 100k miles per SII with BMW oil (dealer service). The next 100k + miles was done at 60% SII (3rd SII light turns off, around 8k miles), with Mobil 1 0w-40 EuroCar LL-01 spec oil.

No oil consumption between changes & still clean (pic is from VCG replacement last year, date on pic (1-1-05) is the default date after battery change)......

Looks nice and clean to me....

I've got anecdotal evidence... seen really bad sludge on a couple of Porsche Cayenne Turbos with 10,000 mile intervals. Gunked up lots of passages and they ran pretty badly even after flushing them a couple times. The owners ended up getting rid of them after a few flushes and they ran "okay."

I know anecdotal evidence isn't great, but... I saw those engines with my eyes which went a long ways to reaffirm my 5k-7500 mile interval. :dunno:

I have alway run engines that I would call highly modified, just as I do now. In the good ol' days most of us swore by a particular brand oil because we had good experiences with the engines we used them in. The preference was just as varied as it is now. I'm not talking about 5-10 years ago, I'm referencing the time before multi-weight, synthetics and high detergent oils were on the market. While I still use one brand of oil all the time I don't think of it as necessarily the king of the hill as my history is flooded with observations to the contrary.

There are so many variables, where on the planet the user is, what the engine is in, what model engine it is, the engine condition, how it is used and/or abused that I find it impossible to draw any solid conclusions from the experiences of others.

I have read many oil comparisons and haven't found any consistency of which oil is the best and none that offers associated tangible benefits. One reason is many are either done or discreetly sponsored by a particular MFG. IMO that leaves an assumed logic that changing the oil AND filter more frequently is a good thing. I am aware some say oil can get better with some miles on it. Wine does, maybe oil does. If that is true and matters,racing engines that are 1,000 plus HP would be aging the oil in another engine before using it in an engine that costs $50,000 and up.

Rebuilding an engine has always been expensive and it is not my favorite thing to do. Many posts here recommend preventative maintenance on fairly inexpensive stuff. Right or wrong, I think being sure the oil and filter are performing at their best is also inexpensive preventative maintenance.

Ven you worry me. Here in No VA everyone's driving is Severe service (harsh too!) Stop and goes, long idle periods everyday and everywhere. I think we just made the top of the USA's worst driving areas. Another great record of achievement! Traffic? We have no stinking traffic!

Steve, you are probably right. But most of my driving is not in traffic hours as I work from home and my wife's work hours are also off peak traffic. :)

The X3 saw only 4000 miles this year. The Jeep saw 3000 in 11 months. The X5 did 2000 since I got it 2 months ago.

When I used to commute, 8000 or 9 months was my interval for the E36 M3 or E46 xi.

Agree with BCRedliner.

An aspect of the oil topic that needs to be addressed every year or so for new members is cheap/knock-off filters.

I think most on XOut agree, Genuine BMW filters are the best bet, and avoid "Iffy Lube" shops that use bulk oil that fails to meet the specs (not to mention BMW filters not stocked, new oil & old filter).

I can't believe jcl changes his engine oil at 20,000km and claims no sludge build up. Ridiculous. To be honest. I'm a new to owning a BMW(2003 x5 4.4i). I've owned it for about 4months now. I like to tinker and fix cars and drive older model cars instead of newer cars. Older cars just have more soul and character to drive. Anyways..before owning my first BMW I knew what I was getting into. BMW already have a bad name for not being reliable..and it goes to show why.... Service intervals. Its a joke when I see 20,000kms+ engine oil service. Its no wonder why BMW leak so much. In this 4month of owning my x5 there has been afew suprises during fixes. I'm so surprised that certain gaskets can even get so brittle or can even happen! Or gaskets literally disappearing/deteriorated. Coming from a Honda car enthusiast, racing them and modifying them.. I'll guarantee you now..my 2000 integra type R(210,000km)/ and 1994 civic with a 2002 model engine dropped in, is internally cleaner and healthier than most of these BMW here period. I have changed heaps of gaskets and worked on alot of cars(non European)..but these BMW are on another level of "how can this even happen".

Oil changes is important. These bmw's wouldnt leak or have so much dam trouble if oil service was done on a regular basis and not by following the dam service light.

Put it this way, engine oil is there not just to lubricate but to also keep engine temperature down(which everyone knows). But keeping good oil in the motor does wonders especially on gaskets and seals keeping them 'rubbery' and well conditioned as they should. Keeping temperature down meaning less expansions on seals and motor.
JCL you may think your motor is healthy.. But internally you don't know what's happening..especially when engine oil is suppose to keep our famous x5 timing chain guides lubed and keeping em from getting so brittle. If anyone's interested I'll even post one of my Honda type R motors that currently sitting on 210,000kms opened.. Which looks almost brand new and HARDLY leaks and see more track racing time too. Despite the BMW having afew troubles.. I still love the thing. Next on the list is valley pan gaskets and manifold gaskets while I'm at it.

BTW whoever says spending 80-110$ every 3month - 5months is a waste of money... Well I rather spend that 110 every 3months then spend 1000$ money fixing.