Originally Posted by Kuchar' post='455652' date='Aug 6 2007, 04:04 AM

Check out what Bavarian Machine Specialties here in Houston has to say about the 15k oil change:
Full Article Link

"I routinely see engines at 45,000 miles that have had two oil changes and are so gunked up that the engine will have serious problems with lifters, rings and bearings before the 60,000 mile mark."


"As a general rule, we recommend oil changes depending on each customer?s driving habits. Usually the mileage period for changes is 5000 to 7500 miles. We arrived at this range based on laboratory analysis of oil we drained from customer?s cars.

For comparison, the following picture is of an engine with 82k that we have serviced for its life time."

Originally Posted by jordan23junkee' post='455627' date='Aug 6 2007, 02:45 AM

yes the bmw dealer uses Castrol full synthetic whuch runs about $12/quart and $5/quart at Autozone. Theyre both the same. Mobil 1 has 0w 30 for European engines fully synthetic which im going to give a try next oil change.

Originally Posted by jordan23junkee' post='455627' date='Aug 6 2007, 08:45 AM

yes the bmw dealer uses Castrol full synthetic whuch runs about $12/quart and $5/quart at Autozone. Theyre both the same. Mobil 1 has 0w 30 for European engines fully synthetic which im going to give a try next oil change.

Originally Posted by cocy00' post='455651' date='Aug 5 2007, 09:03 PM

I say this due to personall experience. Had a E39 which I changed my oil according to schedule and after 3 years of driving it (abt 150k miles), the valve cover started leaking, so had a change of the gasket. When the mechanic took the valve cover off.... it was all yucky and gooey. when I reached the 165k miles mark had to have the head cleaned b'cos the carbon ond oil deposit had bloked all the lubricating holes. Had a E46 and changed oil every 7k miles and its still going strong (abt 200k miles and counting). Had a friend send me his E46 318i engine photos as per attached. Only done 100k km England and you can see the engine yourself. Mind you this was taken when the car was only 3-4years on the road.

Originally Posted by fjwagner' post='455751' date='Aug 6 2007, 05:29 AM

well, I am an engineer and deal with facts and your facts are certainly compelling. Thanks for spending the time to post those pictures. Those combined with my oil analysis will create a conservative approach for me. More conservative than the straight up analysis would suggest. I have a 318 with 152 k miles and it looks good still. However, those intervals have been closer to 7 k. An interval between I Drive recommended changes certainly does sound appropriate for the 530. Fred

Originally Posted by cocy00' post='455753' date='Aug 6 2007, 05:55 AM

Well, I'm also intrigue with your findings.... but I have no doubt that the engine oil can still perform but that doesn't mean that they do not leave residues that will clogged the engine. Maybe BMW did not take into account the dirt which gets blown into the cylinder and also the carbon from combustion or maube they don't want your engines to last that long Anyway, the goeey stuff does not show up in the oil when its being drained and also BMW engines runs much hotter than many other car maker's engine. It just makes you wonder if the oil filters are doing their job at all...