In Reply to: Re: "oil change cost pretty dam expensive"---not a posted by spuds davenport on October 21, 1999 at 16:31:13:
Every time you start you're engine after the car has sat a while, all the oil it in the pan. In fact, starting the engine is the worst thing you can do to it. Except for maybe filling the filter, the difference of which is probably inconsequentially small, the lag in getting oil through the engine after an oil change is the same. Given the benefit of a fresh additive package and the removal of contaminents suspended in the old oil, the change is a no lose proposition, from the standpoint of engine wear.
As far as the oil companies benefitting, this is true. In most conditions, and especially with good synthetic, 3000 is somewhat excessive (depending on environment and driving load). However 15K is too far the other direction. As I've said before, twice a year sounds about right, especially if BMW is picking up one of them.
: : : When you consider the fact that the most possible damage to your engine, is those few seconds after an oil change when there is a lag time before the new oil is pumped to all surfaces, i think that the person who changes more often is at greater risk then one who follows manufacturers reccomendations with synthetic oil...the oil co's love for people to use the'it's cheap insurance" cliche to justify at the best unecessary and at worst damaging idea that more oil changes equal engine longevity. Obviously if you do lots of stop and go and or encounter dusty conditions every 7500 miles or 6mos would be prudent, more than that is overkill!