Engine oil AMSOIL or OEM BMW

From personal experience I have always changed oil every 3500-5k miles depending on how I drove. I used to do 6500-7500k and I noticed on my 540i last winter on days when it got below 20 degrees the engine was very noisy during the first 5-10 mins driving. It was so noisy I was convinced it was piston slap or something. It wasn't a low oil "thunking" sound though. Always kept it under 3k rpms and was very gentle on those cold mornings. This was when my oil had 4-5k+ miles on it and it was last changed in Sept 2024 and this was Jan 2025 back then. So I scheduled an oil change worried my oil was low or something and the noise went away. Oil quantity came out normal no burn or leak! After that I reduced my intervals to 5k max and I also always changed the oil before winter/summer (mid-late Oct and early-mid April) ever since following this personal guideline of mine I have never experienced that cold rough engine sound in the winter anymore. Also two examples of manufacturer oil recommendation being shite is the B58 states 0w-20 but the manual says 0w-30 is acceptable. I also noticed that switching to 0w30 the engine sounded/felt smoother especially on cold idle. Second example is N63tu2 BMW used to recommend 5w-30 but then they dropped it down to 0w-30. Many cases of those motors particularly found in 2018 M550i's etc were consuming 1qt every 3k-4k+ miles yikes! But once switching back to the original 5w-30 recommendation all consumption ceased.

I’m up to 150k miles on my B58. Oil changes every 10k miles from new. Still running smoothly, not burning any oil, pretty sure it’ll go another 50k miles at least. Personally, through 5 BMWs, I’ve always just stuck with the factory recommendation and never had the slightest issue. It’s always been the rest of the car which has gone before the engine.

Fellow mu-X owner here! If you're thinking about upgrading from the standard Isuzu Genuine Motor Oil 10W-30, check out the ZIC X7 Diesel 10W-30 Fully synthetic. I used Amsoil Turbo Truck 5w40 too (10k km interval) but it's expensive for my Garage queen mux haha. Mobil Delvac1 5W-40 is good as well.

I run 0W20 that is approved by BMW and have 255K KMS. No issues at all.

I have Signature in my 25. Smoothed out the engine noises quite a bit.

I maintained 0w-30 factory spec on my F85 and did 2 oil analysis and Data was great. I just changed to 5w-50 leichluf.

160k miles on mine. Most reliable car I’ve owned. Just do your regular maintenance like plugs, coils, filter, oil, other fluids and they’re rock solid!

Engine noise is a little, well noisy, mine is less rumbly/vibrationy after I changed my oil and used Amsoil Hybrid oil. I can’t generally feel anything when the engine kicks on now, before I could definitely feel it every time it kicked on.

My biggest regret, not swapping out the shitty 0w-20 factory filled oil for some 5w-30 Amsoil, Motul, or Pennzoil Ultra platinum the moment I took it home. Don\u2019t wait till 1k miles.

0W-20 at 5K interval. 74k miles.

Gen 1 B58 with plastic oil pump. Increasing oil viscosity is a recipe for failure, especially in cold climate.