[AlmightyGxd]

I have a '16 328i xDrive. I was wondering if there was a difference between these two fluids or if they're interchangeable with the front & rear differential.

https://www.fcpeuro.com/products/75w...red-line-50104 - (This is suggested for the rear)

https://www.fcpeuro.com/products/bmw...413511#fitment - (This is suggested for the front)

I was wondering if I could just get 2 of the redline and use it for front & rear, or if it's better to just use the redline for rear, and the BMW G2 for the front.

[Mkswoosh]

im currently on the same boat right now. i just did a bunch of maintenance and upgrades and really dont want to spend more for the BMW fluids. in the red line website it says 50104 could be used for front and rear diff. Also, on FCP euro the 50104 has both OE part numbers of the BMW front and rear diff listed as well. so im highly leaning towards red line.

really open to others opinions.

[AlmightyGxd]

Originally Posted by Mkswoosh

im currently on the same boat right now. i just did a bunch of maintenance and upgrades and really dont want to spend more for the BMW fluids. in the red line website it says 50104 could be used for front and rear diff. Also, on FCP euro the 50104 has both OE part numbers of the BMW front and rear diff listed as well. so im highly leaning towards red line.

really open to others opinions.

Yeah I’ve seen that it popped up on FCP euro when using the OE p/n. I’d much rather use 50104 since it’s $23 compared to the BMW option which is $50, but if redline is saying 50104 can be used for front and rear diff then I might as well just get that.

[Mkswoosh]

yeah. if you search red line oil selector. their website will prompt you to input your vehicle details. and once you scroll down to the diff oil portion it'll say front and rear diff fluid. so you should do that just to verify for your model. mines is a 340i xdrive. the only thing im skeptic about is the OE rear fluid is rated for GL4 fluid found in the BMW G1 fluid. so the red line 50104 is GL5. not too sure about that bit of information. so im still on the fence until i could get feedback by others.

read something about the additives found in GL5 fluids wouldn't affect the diff since it wont get hot enough for it to be exerted. im sure im just over thinking it though lol

[AlmightyGxd]

Originally Posted by Mkswoosh

yeah. if you search red line oil selector. their website will prompt you to input your vehicle details. and once you scroll down to the diff oil portion it'll say front and rear diff fluid. so you should do that just to verify for your model. mines is a 340i xdrive. the only thing im skeptic about is the OE rear fluid is rated for GL4 fluid found in the BMW G1 fluid. so the red line 50104 is GL5. not too sure about that bit of information. so im still on the fence until i could get feedback by others.

read something about the additives found in GL5 fluids wouldn't affect the diff since it wont get hot enough for it to be exerted. im sure im just over thinking it though lol

Yeah this is confusing in a way. I might send FCP euro a message and see if they’ll say if redline is fine for front & rear differential or what. On the fence as well, but seems like we’ll just have to look into it more or something. Redline does say its front & rear differential for me too.

[AlmightyGxd]

Mkswoosh Talking to FCP euro support , they recommended using 75W90 for the front, which leads me to more confusion . I sent redline a email to see what they say. FCP Euro sells Liqui moly 75W90 for $19.19 and it’s fitment noted for the front. Redline also sells a 75W90 GL-5 for $23.58

I’m starting to guess 75W85 is good for the rear & 75W90 is good for the front.

[TX552]

Originally Posted by AlmightyGxd

Mkswoosh Talking to FCP euro support , they recommended using 75W90 for the front, which leads me to more confusion . I sent redline a email to see what they say. FCP Euro sells Liqui moly 75W90 for $19.19 and it’s fitment noted for the front. Redline also sells a 75W90 GL-5 for $23.58

I’m starting to guess 75W85 is good for the rear & 75W90 is good for the front.

I replaced rear differential oil recently with redline 75w90. We tend to overthink about these things, as did I about g1 hypoid vs Liqui moly vs redline and went down the rabbit hole in this forum.

I say either one is fine, just have enough fluid of your choice. 85 vs 90 and gl4 vs gl5 are all noise in my opinion. Pick one and don’t look back.

[Mkswoosh]

yeah, i looked around the forum and pretty much the censuses is pretty much even, do what you like as long its in the range. for me i'm sticking with redline front and rear. im thinking FCPeuro is just going by the books with each bottle type of certifications. i have yet to stumble upon any "oopsies" when it comes to diff fluid in the forum.