[wolfe]

I don't want to start a 'what oil is best argument', but I'm hoping some people here have already figured a lot of this out with their own cars.

My last bmw used bmw/castrol 5w30 synthetic oil, changed at 15k, 32k, and every 5-6k thereafter. It now burns quite a lot of oil, about a quart every 2k miles. I know BMW states anything above 1 quart/750 miles is considered normal. I've spent some time and money troubleshooting this, and it appears to be due to poor cylinder oil control.

In short, I want to start out right with the 128 both by using an oil well suited to my needs and by changing it often enough.

Some people have suggested I look at a 5w40 oil because of the hotter ambient temps (high 90s, low 100s in summer). Others have said because the N52's valvetrain has a lot of moving parts including valvetronic, that 5w30 is a better choice as it'll lubricate the valvetrain faster on startup. I've also been told that this engine in other countries would run a thicker oil, but the CAFE regulations in the US mean that BMW has specified a thinner oil to help with fuel economy and emissions. I haven't been able to verify this.

I've looked at several brands including redline, castrol, motul, and Total/elf, and there simply doesn't seem to be any clear 'winner' in terms of specifications. One might be thicker at operating temperature, while another has a better HTHS rating. Some have a much lower TBN additive rating, but are thinner when cold and thicker when hot.

From my own personal experience, the BMW oil doesn't seem like it's offered as good wear protection as I would have liked. This could well be due to the long oil change intervals before I owned the car, and/or improper break-in. I want to be on the safe side and use an oil known to be better quality in the new car.

Maximum wear protection and cleanliness is more important to me than how long I can leave the oil in there or (to some degree) the cost of the oil. I plan to change it around 5k intervals, plus a break-in service at 1200.

I would be interested to see what people's thoughts are specifically on the viscosity grade.