Mordor110

Just change it when the odo rolls over every 5K increment. I.E 20K, 25K etc. That way you change it early and it's easy to remember.

BMW535xia

obtain some "clear" oil change windshield stickers, and do it old school, or keep a small notebook which can also be used for "noteworthy" observations, concerns, etc.

ASpec818

Just got an oil change from the dealership but the oil change counter is at 9000miles. Did they forget to reset it?

balbs

If they did you can just search YouTube on E60 service reset and do it yourself.

SilberGrauE60

Not when BMW is paying for the service!

SilberGrauE60

If you had them do an oil change before the counter shows it is due, they will not reset the service indicator.

tpaxadpom

Is 15000 miles fixed interval? I thought the car will shorten that interval if you don't drive like a gramma.

SilberGrauE60

The counter starts at 15000 miles, and counts down based on how you drive the car. That's why its called condition-based service (CBS). Shorter trips that don't keep the car at full temp for extended periods will cause the counter to click down much faster than actual miles driven. For example, I have put only 5000 miles since my oil change and my counter is showing 7000 to go, or in other words, has used up 8000 miles of oil life in only 5000 miles. Actually, driving like a "gramma" is not the way to use it. You want to get the car to operating temp and drive long periods at full operating temp.

tpaxadpom

Thank you for the explanation SilberGrauE60. That's is how I thought it works. Though most people on the forum think 15000 miles is way too long for oil change interval. I understand there is a big difference on how these cars are being driven. I am trying to understand where 15000 miles came from. Is european synthetic oil recommended by BMW not good enough for 15000 miles and BMW having the free maintenance wants to screw us over? Instruction manuals in my older japanese cars suggest changing conventional oil (non synthetic) every 7500 or 5000 miles depending on driving conditions. Most shops will tell you to do oil change every 3000 miles. If we assume more or less ideal conditions, long freeway trips, is 15000 miles acceptable from the oil longevity point of view?

BimmerFan52

15,000 miles came from BMW's marketing department.

Sometime back car manufacturer's began comparing and expressing luxury car cost as TCO or "Total Cost of Ownership", which includes the purchase or lease cost coupled with maintenance costs. In order to lower the TCO the manufacturer includes free maintenance (basic oil, filter changes, etc.). The fewer the number of oil and filter changes the less the expense for the manufacturer. A few synthetic oil manufacturer's claimed that their oil could go 15,000 miles so I think BMW latched onto those claims.

In order to provide some "science" behind the practice, BMW used an algorithm to measure engine temperature, average speed and trip length to estimate the wear on oil.

In more recent models BMW (as well as a number of other manufacturer's) measure the dielectric constant of the oil (the relative speed of an electric field in the oil compared to an electric field in a vacuum) in an attempt to measure changes in the oil which according to theory are related to changes in additive levels in the oil as well as contaminants. This technique was originally developed by tribologists who monitored lubricant quality in industrial machinery where down-time to change oil may be measured in tens of thousands of dollars per hour. The dielectric change does not tell them when to change the oil, but rather that a change has taken place in the lubricants characteristics and there is a need to send an oil sample to a laboratory for analysis.

While on-board oil sensors may some day be sophisticated enough to tell you exactly when to change your oil, no system is sophisticated enough today to say when just enough of the additives are left and when the level of oil oxidation is just barely acceptable.

When oil oxidizes past a certain point its pH becomes acidic, and some engine gaskets can be adversely effected becoming more brittle and shrink.

Oil does not age based upon miles, but rather hours of operation. And each individual engine is driven under different conditions and may have a different level of health, affecting oil contamination by fuel, coolant, condensed water vapor and soot. A highway driver's 15,000 miles of operation may relate to 300 hours of engine operation at an average of 50 mph. A city driver's 15,000 miles of operation may relate to 1500 hours of engine operation at 10mph average speed.

A good rule of thumb is to change oil twice per year, once every 300 hours of operation or every 5,000 miles, whichever comes first. To keep it simple, error to the conservative side.

If you change your own oil, and change it every 5,000 miles as compared to every 15,000 miles, how much more will this cost you over 105K miles? Assume worst case you drive a V8 that uses 9 quarts of oil per change. Buying a good quality filter at $10 and oil at $4.50 per quart (M1 at Walmart @ $22.47 per 5 quart jug) each oil change is about $50. At 5K mile drain intervals you will change the oil 21 times for a total cost of $1050. At 15K mile drain intervals you will change the oil 7 times for a total of $350.

Assuming you drive 12K miles per year, 105K miles will take 105 months. The additional $700 costs $6.67 per month, or roughly the cost of two premium coffees.

Given the cost of replacing engine gaskets, or the effect of sludge on the general health of your engine, is your BMW worth $6.67 more per month for the piece of mind that your engine is being treated to the best care possible?

I maintain that frequent oil changes are very cheap insurance.