Best Clutch - Oil - and Rear differential fluids for 88 M6

[M6SCOTT]

Is anyone oil REALLY better than the next such as Motul over Castrol ?

Best fluid for clutch and rear differential RedLine ?

[dcains]

You'll get 10 different answers from 10 different people. For clutch hydraulic fluid, though, just about anyone can agree that DOT4 is what is required, and you can't go wrong with the Ate Typ 200 (or Super Blue, if there's any left).

My car came with Liqui-Moly 10w-40 MoS2 in the engine, and I'm still not sure how to feel about that. Lots of German car guys and shops recommend it, but I've been using Mobil 1 since it was first released in the late 70's. I hate pulling the dipstick and seeing gray oil that looks like it's been in there forever, and I suppose even if I do switch to Mobil 1, it will take a few fluid and filter changes to flush all the MoS2 particles out of the system, if ever.

The most important thing is to meet the required spec from BMW. Very important in the gearbox, especially. I've been using Redline in my cars since the late 80's and it's been fine.

[M6SCOTT]

Have had RedLine in my wife's 07 X3 for a long time.

[alpinacsi]

Clutch hydraulics are piggybacked off the brake hydraulics. As previously mentioned: ATE fluids are very good and everyone will have an opinion. Use one that meets or exceeds factory requirements.

Trans fluid is a different story and is separate from the clutch hydraulics. Your trans might have ATF installed as that was recommended for some 5speeds. Check your manual for fluid requirements and know that some people prefer a heavier fluid. I have always used the MTL from redline.

Diff fluid is also something that you should refer to the factory spec on and choose a fluid that meets or exceeds requirements. Again, I use redline products that meet the requirements.

[RSheiman]

I swapped all fluids to Redline when I purchased my M6....and yes, there is a green sticker on the tranny that says ATF but I put in MTL and have been happy with it.

[n2bimmer]

Clutch hydraulics are piggybacked off the brake hydraulics. As previously mentioned: ATE fluids are very good and everyone will have an opinion. Use one that meets or exceeds factory requirements.

Trans fluid is a different story and is separate from the clutch hydraulics. Your trans might have ATF installed as that was recommended for some 5speeds. Check your manual for fluid requirements and know that some people prefer a heavier fluid. I have always used the MTL from redline.

Diff fluid is also something that you should refer to the factory spec on and choose a fluid that meets or exceeds requirements. Again, I use redline products that meet the requirements.



Thank you..

[DaHose]

Yeah, this discussion happens ad nauseum and there are numerous threads giving lots of details.

To me, the bottom line is this.
1.) Shell Rotella T6 synthetic diesel engine oil with a Purolator Pure1 filter is the best possible combination for oil. The M6 just uses a standard paper cartridge, so order whatever.
2.) The 280 tranny likes ½ fill of regular (dino.) GL4 oil and ½ Redline MTL or MT-90. If it’s always cold, use the MTL. You’re in FL., so I say use the MT-90.
3.) Just use a good quality DOT4 brake fluid. Any main brand is fine.

Jose

[Looghis]

I used royal purple synchromax in my trans because its designed for gearboxes that require atf. and royal purple max gear 75/90 in my diff. they both are working great and dont leak.