Which oil for '88 M5?

[Steve1807@xxxxxxx]

I'm about to take the plunge and (hopefully) pick up an '88 M5.  I've seen a 
number of discussions on the NG about which oil to use, and was wondering if 
there was a consensus?  I use Mobil 1 5w-30 in my other cars, but wasn't sure 
if this would be too "light".  10w-30 or 15w-50 Mobil 1?  I've seen Castrol 
5w-40 Syntec "truck" oil also.  Any recommendations?

Thanks,

steve

steve1807@domain.elided

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