Differential oil for E86 3.0si Coupé

[fredej]

I'm considering having the fluids in my gearbox (manual) and rear axle differential changed.

I have talked to my local (Sweden) independent BMW specialist to get an estimate of the job.
On their list of parts they have specified that the 3.0si Coupé should have SAF-XJ FM Booster oil. I was a bit surprised because I thought that oil was specifically for cars with the LSD. But the specialist insisted on that's what comes up in their system (BMW-ETK).
I think that SAF-XJ Booster is 75W140 rather than 75W90 that's usually is used by BMW in open differentials.

I checked myself in RealOEM (and BMW-ETK.info) and that is actually what those system specifies for the 3.0si Coupé. See screenshot from RealOEM.

Looking at the part number for SAE-XJ Booster in RealOEM, the 3.0si Coupé is the only car not an M-car that the oil is listed to be used with.
Can that really be correct?

 

[Liam22]

There's nothing special about the 3.0si differential. Capacity is ~1l (not 3x0.5) which also points to a mistake about the large case.

 

[fredej]

Thanks for your input!
Yes, it makes sense that E86 3.0si would use the same type of differential oil as the rest of the non-M Z4s. I can't think of a reason why it would use oil designed for LSD when it has an open differential. It has to be a mistake in BMW-ETK. By the way, BMW's oil for LSD equipped M-cars (SAF-XJ + FM Booster) is really expensive at ~£97/Liter!

Looking at TIS it clearly shows that the N52 E86 has a 188L differential and that only the M-cars has the larger case including a locking differential (screenshot below). More, TIS specifies 1L oil capacity (thanks Liam!) for the differential and has a table that lists oil types used in BMW rear axles. The E86 non-M falls in "all others vehicles" category which means oil typ BMW Synthetics OSP / SAF-XO (75W90).

I will talk to the garage and if they still insists to follow the information in BMW-ETK, I will go elsewhere.