My comments below:
- Typical climate your E70 operates in (temperatures, etc.) - Washington, DC Metro area 0F - 100F with LOTS of traffic with stop and go driving. Very hard on any vehicle. Run hours are higher than mileage typically. Average MPH per tank is usually only around 18-22. NOTE, this is MPH not MPG!
- Oil brand and specific type (a link to the oil webpage or PDF technical data sheet would be great as well) - Castrol 5W40 which has the BMW LL-01 Approval on the bottle, or at least it did last time I purchased it. Like anything the Approvals come and go depending on a lot of factors. I am not 100% hung on on BMW LL-01 oil in my vehicle because I do not believe or subscribe to the 15k mile OCI. In fact in my E46 I have reprogrammed the OCI reminder from 15k miles to 7500 miles.
- Oil filter brand - Mann brand filter usually from the dealer or online
- Typical oil change interval - About 10k miles, do not believe in the 15k mile BMW interval
- List any additives used - None. Occasionally on other cars add a can of SeaFoam or STP Multipurpose Motor Treatment about 250 miles before oil changes. This helps keep the crankcase clean.
- And a brief note about why you chose said oil/filter/additive would be great -
I do not get all wrapped up around the axle on BMW LL-01 Approvals. Some folks might. Once any vehicle is beyond the Warranty, the specified oil may or may not make much of a difference. I do not extend my oil changes to the max mileage and I am not racing or tracking my vehicle, it is a daily driver. My attitude is any good quality synthetic oil that is clean and not contaminated is more than adequate for the majority of vehicles on the road.
I do not want hear about sheer numbers and all the other oil related specs, few people care or understand. Also the folks that preach all of the petroleum specs never explain them because either they do not understand them or they think they are so much smarter than everyone else. I frequent another forum where one member continually tells people they are using the wrong oil. Funny how the engines have not immediately seized on all of these vehicles. Just because and oil does not meet some spec, does not mean it will cause catastrophic problems with an engine. The API standards that were recommended for the E70 are usually exceeded by most of today's current synthetic oils unless you are buying the cheap, not synthetic oil from the Dollar Store.
Clean and uncontaminated oil is the import part of any engine longevity. You cannot always rely on mileage to determine if the oil is clean. SO MANY people drive there cars in severe situations where the oil will not come up to temperature and cook off water and fuel in the crankcase. This is often due to short drives, severe low temperatures and also soft failing cooling system thermostats. Also keep in mind the 9 quart oil sump in the V8 takes about 3 times longer than the engine to come up to temperature, so in the very coldest parts of the years, this may mean up to 30 minutes of driving which many people do not do on a per trip basis.
I almost always change my oil in late Fall, regardless of actual mileage on the oil. This way I start out the Winter months with a fresh oil change so hopefully I can get through the Winter without severely contaminated engine oil. I also monitor the engine oil color when checking the oil as my E70 still has a dipstick, but I understand dipsticks are going the way of the dinosaur these days.
Not here to have a discussion, just stating my position and reason that I do what I do. Choose to take some or none of what I have to offer, but my approach has worked well for me over the years and I have never had an oil related engine failure.
Each person does things differently. This is how I operate.
As they say, YMMV.