Oil recommendation 1989 BMW 535i/M (M30)

[cwlesq]

I have read a ton of posts, but would still appreciate your thoughts on oil for my baby. She is a E34 535i/5 speed (1 of about 1100 built in the 1989 model year) with the M30 motor with about 160,000 miles. The valve cover was off last month and there was no sludge in slight. She resides in the garage and is driven on the weekends, because I have a company car for work. When it is driven, it sees short trips (>10 miles) and an occasional hwy run. I drive the car fairly aggressively, but the motor never sees more than 4800 rpms...never.

During a recent run on Supertech 5w30 syn (Yes - I know the M30 likes "thick oil", but I read the AE Haas article and went off the deep end), the motor burned less than 1/4 quart for 2600 miles, so even with thin oil, it burns little oil for an m30. Preparation for winter, it currently has PYB 10w40 in the crankcase (250 miles), but I am growing weary of 3k oci, and would like to increase to a 7k+ oci and/or follow the oil inspection indicator.

Many of the BMW guys run Mobil1 15w50, but that seems mighty thick for a New Jersey in year-round use. The same is true for 15w40 oils - just seem too viscous for the Northeast winter. I have considered 5w40 diesel oils, but Rotella T6 and TDT aren't much thinner than 10w40 @ 40C, according to the PDS. Based on my searches, I could run these oils year-round:
-Mobil1 10w40hm
-Castrol Syntec 10w40
-Maxlife semi syn 10w40

With all of that in mind, what are your thoughts and suggestions?

As always, thanks in advance. This is a great forum.

 

[dparm]

The KV @ 40C figure is not really that useful for comparing low-temp performance. 40C = 104F...most oil will spend almost no time at that temperature.

MRV/CCS values are more relevant when it comes to very cold starts.

 

[cwlesq]

dparm: Thanks for the clarification. In light of that distinction, what's your suggestion?

 

[CATERHAM]

To bad you don't have an oil pressure and/or oil temperature gauge as it eliminates all the guess work out of recommending an oil viscosity.
Anyway Mobil 1 0W-40 or Pennzoil Ultra 0W/5W-40 is the heaviest oil you should need to use.
I'm not as familiar with the M30 engine but the M52 and newer L6 NA engines actually don't require anything heavier than a light A1,A5 0W/5W-30 synthetic oil even for fast street use.

 

[cwlesq]

Caterham: You're right about the oil pressure gauge. I only have an "idiot light" for oil pressure. Thanks for the advice on the 0w40 Mobil1, it's easy to find and comparatively cheap at Wally World. Many of the UOAs for Mobil1 0w-40 have an oci of about 5k, no problems running this oil 7500?

 

[CATERHAM]

M1 0W-40 is an approved BMW oil meeting the LL-01 long drain spec'. So 7,500 miles should be no problem.

 

[cwlesq]

Caterham: Thanks for the reply. Mobil1 0w-40 it is.