View Full Version : Oil Change Frequency, 15,000 miles Really?

02-02-2005, 04:27 PM
Have new X3 and was wondering if I should get my oil changes more frequently than the suggested 15,000 miles?

02-02-2005, 04:36 PM
You probably do not need too. Not with the X3. I would probably recommend changing the "filter" every 5K though b/c of city driving. At most, you probably would do every 7500 miles ... no need to do more with synthetic.

So, I would do the oil change at 15K; but, change the filter every 5K. The filter is what is important to the equation.

02-03-2005, 08:03 AM
I change my oil and filter when the computer says that it is about half way through service interval. This works out to about every 5,000 to 7,500 miles. I only reset the service computer on every other oil change.

The only reason that BMW now recommends the 15,000 mile interval is that they are paying for the service as part of their free service program on new cars. In fact, BMW had an issue with the oil filters not being able to stay intact past about 11,000 miles and had to make the filters more robust to last 15,000 miles.

The free service program is also the reason the other lubricants in your BMW are now magically good for 100,000 miles when just a few years ago BMW recommended changes about every 30,000 miles.

The main reason that you need to change oil is that as you drive the oil slowly gets contaminated with dirt, fuel, moisture, metal, etc. The filter removes some of these, but not all of them. The additives in the oil help to buffer the fuel and moisture effects, but the additives eventually get depleted and the oil gets saturated with small particles that the filter does not remove. By changing your oil and filter, you remove these particles from the inside of the engine and refresh the additives.

I don't think you need to change the oil "every 3,000 miles" like the quick lube places want you to, but every 15,000 miles like BMW now "recommends" is probably at the limit of the engineers at BMW would except.

02-06-2005, 03:43 PM
I agree with the note above that points to BMW NA's oil change interval being driven by economics vs. good engineering sense.

I certainly don't have a scientific sample size, but a dozen cars over the years, including 5 currently with three with over 150 kmiles, has validated my practice of changing the oil and filter every 5 kmiles, regardless. None are using oil appreciably, and one has over 300 kmiles and still only needs a quart between changes. Synthetic oil can certainly extend the change cycle duration but 15K miles, about a year in typical car, just seems too long.

Changing the filter is a must between intervals. Changing the oil, in my mind, is good insurance as well, and it's so cheap, why wouldn't you do it? The cost for the oil (except for the M5) is insignificant compared to the expense/inconvenience of rebuilding the top end or the whole engine. Besides, as the car ages, climbing around underneath it keeps you in touch with other things that may be getting ready to fail.

Change your own oil and stay in touch with your car.

00 M5
94 F150 (the ultimate beater vehicle!)
92 Grand Caravan (wife's beater)
+2 others with the college kids

02-07-2005, 10:50 AM
i've been changing the oil filter and the oil every 75k. and change just the filter at around 3k. With Mobil-1, the oil should be plenty good for at least 75k. Changin oil filter every 3k is a cheap insurance.

02-07-2005, 12:32 PM
i've been changing the oil filter and the oil every 75k. and change just the filter at around 3k. With Mobil-1, the oil should be plenty good for at least 75k. Changin oil filter every 3k is a cheap insurance.
I hope you meant 7,500 miles and not 75,000 miles :-)

02-07-2005, 12:41 PM
oh yeh.. :) 7500 is what i meant. :)

02-08-2005, 03:31 PM
If you drive short daily trips like I do (15 min one way) I wouldn't wait to 7500 miles. Make sure to have it changed at least every 6 months maybe sooner in the summer (humid) months. As for the rest of the fluids, don't believe for a second that BMW has finally reached the holy grail of everlasting fluids. It blows my mind that the marketing department is willing to risk BMWs reputation as a very reliable auto just to save a couple bucks. Very shortsighted on their part.