Quote:
Originally Posted by zkeeper
It's not break down of new oil that is the concern on really any decent motor, not withstanding any new car. It's to remove any swarf, any thing that could interfere with rings and bearings. It's not the oil issue, it's the motor cleansing. I will get tons of disagreements...but
Personally, I would change any new motor's oil--if you wish longevity. To run a new motor of any make for upwards of 10K is IMHO, just not wise.
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Nail on the head.
Modern motors are machined to very exacting tolerances, but the effects of temperature expanding the shapes of every metallic piece will invariably be every so slightly out of alignment out of the projected engineered ideal. -Anyone remember the E36 M50 motor cylinders that would have a tendency to become oval shaped? That metal didn't just disappear, it mostly went into the oil system (some out of exhaust, but a small percentage, ~3%). It was because we as a species didn't know 100% about the nikasil composition, thermal expansion properties, variances in machining and casting, etc. Let alone every engine block's crystalline structure is different. BMW took a bit of a risk on a new alloy, and they wound up having oval shaped bores after a long period of time. They simply wore unevenly. Thankfully it took a long time before compression was affected, and the rest of the car was thoroughly worn out - but the mass loss of metal was measurable. Let us not forget that these are still machines that have a large percentage of metal sliding against other pieces of metal.
After the manufacture of a new engine, it's engineering is never perfect - there is a break in period where all of the major parts are designed to wear just enough to create a perfect fit. Why else would you hone a bore? If they wanted the bores to be perfect, they would have lapped their surfaces instead of intentionally roughed them up. So, I'm talking below micrometers of material being shaved off here - but that amount of grit in a bearing is like chewing on a burger with sand in it. You are going to notice. You don't want those break-in byproducts circulating through your engine and scraping away your bearing surfaces for very long. ESPECIALLY if you plan on increasing the power output of the motor in any fashion. As a point of example, formula 1 cars are warmed up intravenously to bring all of their mechanical pieces into the exact thermally expanded size that they were designed to operate at - else they will either fail or wear down so quickly during warm-up that they will not perform correctly. Our cars don't have that luxury, so they have to have relaxed tolerances to operate in a wider temperature range, and for more than a few races.
Change your oil & filter after 1,000 miles or so after you get your car. Don't even think about it, just do it. It's less than a hundred dollars to do so on a multi-thousand dollar car and it will be very beneficial to it's longevity.
Edit: I was actually surprised when I bought my 135 that this wasn't a standard procedure. I'm pleasantly surprised and delighted that this is something BMW actually recommends on their new generation. Regardless, I still changed both oil and filter on my own after I hit 1K miles.