BMW Hypoid Axle Oil G4 Equivalent?

[afree]

The Supra manual says to use this in the rear diff (G3 for non-LSD, G4 for LSD. I thought they were all LSDs in the Supra?). Is there an alternative? The relabeled stuff you get from Toyota is just the BMW bottle with a 75W-80 GL-5 sticker over the BMW G4 label. This stuff goes anywhere from $50-$70 a pint!

I was thinking of using Redline 75W-90 or Motul 90 PA. Any of these good?

"Toyota" bottle:

 

[Marcozi]

Go to the Redline website and find what the company recommends for your car. Redline makes great products.

 

[jeepman3071]

I use Redline in my differential.

 

[Jimmy_Russells]

There are a fair amount of 75w80 GL4 oils on the market

 

[drtyler]

There are a fair amount of 75w80 GL4 oils on the market

Don’t think it is GL-4 oil. Bottle shown has GL-5.

 

[afree]

Don’t think it is GL-4 oil. Bottle shown has GL-5.

That is my confusion. Does G4=GL-5 or GL-4 (or both)? Is BMW's G rating not equivalent to the API rating? Motul 90 PA is good for both GLs.

 

[BMW Dom]

I think you're confusing G4 with GL-4

Another vote for the Redline, all though Valvoline 75w-90 might be a good pick, too

 

[tvaughn]

Confusing wording, but for the LSD version that's a GL5 75w80 which Motul makes, $15 per liter here: https://www.bimmerworld.com/Fluids/...d-BMW-E9X-M3-MTF-LT-2-Transmission-Fluid.html

Also interesting is that in my car (M2) it specs a GL5 75w140 instead of an 80/90 weight.

 

[4WD]

Don’t think it is GL-4 oil. Bottle shown has GL-5.

Yeah - and so is Delvac 1 - what the Porsche guys like ...

 

[D0nat]

Redline official site recommends 75w85 LSD oil for this differential.

 

[chris719]

Confusing wording, but for the LSD version that's a GL5 75w80 which Motul makes, $15 per liter here: https://www.bimmerworld.com/Fluids/...d-BMW-E9X-M3-MTF-LT-2-Transmission-Fluid.html

Also interesting is that in my car (M2) it specs a GL5 75w140 instead of an 80/90 weight.

M active differentials F8x and later use BMW (Shell?) MSP/A (EU) or Castrol SAF-XJ without FM (US). 75w-140.

 

[D0nat]

Yo guys,
I try to bump this thread.
I’m planning to change oil in my rear LSD in BMW 3 series.
Refer to manual it should be filled with BMW axle oil G4 which is equivalent to 75w80 or 75w85 with friction modifiers to handle clutch-type LSD, I guess.
Seems to be original oil is overpriced.
Otherwise Redline recommends 75w85.
But I found a post from a guy on Toyota Supra A90 with the same LSD where he changed fluid with redline 75w85 and under 10°C it work not so smooth as original fluid. After switching back to BMW fluid everything was smooth as before.
What do you think of that?

 

[someonesomewhere]

Yo guys,
I try to bump this thread.
I’m planning to change oil in my rear LSD in BMW 3 series.
Refer to manual it should be filled with BMW axle oil G4 which is equivalent to 75w80 or 75w85 with friction modifiers to handle clutch-type LSD, I guess.
Seems to be original oil is overpriced.
Otherwise Redline recommends 75w85.
But I found a post from a guy on Toyota Supra A90 with the same LSD where he changed fluid with redline 75w85 and under 10°C it work not so smooth as original fluid. After switching back to BMW fluid everything was smooth as before.
What do you think of that?

I think it's real world experience from a real world owner. Up to you whether you follow his experience or not. I would look around and see if I could find more substantive reports from more owners before deciding on a purchase.

Or follow my advice: You can't go wrong with factory spec fluids. If you're going to try a fluid of a varying spec, use one that has A LOT of real world reviews/feedback from lots of real world owners. Transmissions and differentials aren't cheap, and they're not fun to remove/replace. My $.02!

 

[afree]

Brining this back up:

The Supra has an electronically controlled LSD. Does it matter if it has LSD friction modifiers in it? Such as Motul 105778 (LS) vs. 105777 (non-LS)?

 

[tvaughn]

Brining this back up:

The Supra has an electronically controlled LSD. Does it matter if it has LSD friction modifiers in it? Such as Motul 105778 (LS) vs. 105777 (non-LS)?

I thought the new BMW diff for LSD's fluid has FM in it? https://www.ecstuning.com/b-genuine-bmw-parts/hypoid-axle-oil-g4/83222447362/

 

[afree]

I thought the new BMW diff for LSD's fluid has FM in it? https://www.ecstuning.com/b-genuine-bmw-parts/hypoid-axle-oil-g4/83222447362/

Me too. However, some have said the LS version has increased friction modifiers which could mess with the electronic LSD's preload calibrations. Not sure how true this is.

 

[tvaughn]

Me too. However, some have said the LS version has increased friction modifiers which could mess with the electronic LSD's preload calibrations. Not sure how true this is.

This is the OE BMW fluid that they would use under free maintenance, so it is hard to believe it would be incorrect.

 

[Jimmy_Russells]

I put the G4 into my X3MC about eight or nine months ago and I haven’t noticed any difference in performance. It’s what the VIN calls for in the dealer system as well.

 

[afree]

This is the OE BMW fluid that they would use under free maintenance, so it is hard to believe it would be incorrect.

BMW would use their G4 oil. I'm thinking of other oils like Motul Gear 300 LS (GL-5) vs 300 non-LS (GL-4/5).

From another forum:

The LS version added friction modifiers designed to reduce noise, vibration, and harshness (NVH). “However, since the limited-slip functionality in the Supra’s drivetrain is managed electronically rather than mechanically, it doesn’t require those friction modifiers. In fact, using the LS version could potentially cause concerns about compatibility with synchronized gearboxes.”

 

[tvaughn]

BMW would use their G4 oil. I'm thinking of other oils like Motul Gear 300 LS (GL-5) vs 300 non-LS (GL-4/5).

From another forum:

The LS version added friction modifiers designed to reduce noise, vibration, and harshness (NVH). “However, since the limited-slip functionality in the Supra’s drivetrain is managed electronically rather than mechanically, it doesn’t require those friction modifiers. In fact, using the LS version could potentially cause concerns about compatibility with synchronized gearboxes.”

Interesting, that has changed from the F-gen M cars. Maybe that new GL5 Hypoid Axle Oil G4 (that's confusing) I shared doesn't have friction modifiers. That could explain the change from the Castrol Syntrax SAF-XJ 75w140 fluid they used in my generation M cars.