Any harm in using this fluid in the trans vs a w90 oil?


http://www.redlineoil.com/product.aspx?pid=140&pcid=7


Any harm as in, is there a specific reason why this wouldn't work? I use it in my Evo that pushes 300lbft of torque through the transmissions - red line as a whole is probably one of the best oils I've ever used period. Reasons to use - lighter, smoother shifting. i think the base coopers push about 120lbft through the trans.


specific, detailed answers please!

 

What year R56 do you have? I've ran Red Line in many different vehicles with zero complaints.

 

base Cooper r56 - the question is more regarding going from 75w90 to 75w85

 

perfect, thanks for that! i did probably 2:1 ratio 90 to 85, next time i will just go straight 85! red line already shifts way smoother than amsoil's mtl

 

From my experience, if you live in a colder climate the Redline is no good. I had terrible grinding on my first to second shift. Replaced with stock (extremely expensive MT-LT4 fluid from MINI) and it feels much more solid. The cold for whatever reason did not agree with the fluid and gearbox, because once everything warmed up it was better.

 

redline is definitely thicker than most OE fluids, I have noticed. still my go-to oil of choice for all bits, as I am autoxing the car quite a lot.

 

switched to 75w85 red line for the trans and she is shifting very, very smooth.

 

No surprise at all shifting feels more effortlessly when going thinner. Factory fill is BMW MTF LT-4 75W-90 GL-4, while you went 75W-85. That's roughly 15 cSt vs 11 cSt at 100°C. While that's a not so huge decrease in viscosity (little more than 25 %) and it likely won't do much if any harm (contrary to going much thinner e.g. with 75W-80 which is half as thick as stock both cold and hot) I'd keep using BMW MTF LT-4 (75W-90 GL-4). VOAs as well as real-world experience have proven it's excellent. Personally I'm on my forth gear oil fill (and just went back to OE MTF LT-4). While Ravenol MTF-2 75W-80 provided even better shifting compared to BMW MTF LT-4 I didn't want to take a risk and compromise transmission life, which is to expected with a thinner oil. Thinner (lower viscosity) equals to thinner lubricating film thus increased wear in particular when hot. However I'm still debating if I should go 75W-80 next. I'll decide after coming winter season.

From another discussion: