Ok so I gave up on BMW and instead wrote to Fuchs oil who made the oil that's in our differentials from the factory:
Hello, I own a 2015 BMW X3 xDrive35i SUV. According to the latest BMW technical information, the rear differential gear oil BMW recommends is part number 83222413512 Hypoid Axle Oil G3 which they say is also Fuchs Titan EG 4218. The front differential gear oil they recommend is part number 83222413511, called Hypoid Axle Oil G2. Is that also produced by Fuchs? If so what is it? Could you provide more technical details regarding these oils? I have searched for days on the Internet, spoken to BMW dealers, etc and cannot determine what API service class (GL-5, GL-6, etc) or even what SAE Viscosity Grade (75w90) these oils are. All I could find on the Titan EG 4218 was an MSDS sheet.
Thank you,
Thomas Reynolds
His response:
Hi Thomas,
TITAN EG…. are a range of oils only for first fill applications. They are sold in bulk to BMW and other OEM’s. They are not made available for the service fill on the same names.
We produce service fill products under more consumer friendly names and packaging. TITAN SINTOPOID LS SAE 75W-90 (PI Sheet Attached) is the product for your BMW axles as per the following link to our oil chooser https://www.fuchs.com/de/en/products...s/oil-chooser/.
Please let me know if you have any other questions?
Best Regards,
John Anderson
Product Manager – Automotive & OEM Fluids
e-Mobility co-ordinator North America
FUCHS LUBRICANTS CO.
Using their oil chooser I did confirm what he wrote. I emailed Redline to ask if that oil is the same.