At the moment I have RP 75w90 in my trans. Im thinking of trying out Redlines mt fluid. Is there any danger in switching the 2? I don't think there can be but I wanted to make sure.

Now onto my real curiousity. I have recently heard of other car owners mixing 2 or more brands of synthetic mt fluid. Has anyone here tried this? and with what results?

 

Manufacturers keep the additives in certain proportions:
1. Going 50:50 will give you your own random blend of additives that probably won't be as good as either component. But it won't cause any serious problems.

2. Mixing in a little bit of a 2nd oil won't throw the ratios off significantly. It is always okay to switch from any oil to any oil, be it engine, tranny, diff, synthetic, or non-synthetic (assuming the new oil is good oil). It is likewise okay to top off with a little bit of a different oil.


As for RP vs. Redline, I read a bunch of forum posts while back (different forum) from people who had tried many different MT oils. Some oils allowed faster shifts, including Redline and Royal Purple. Some oils reduced grinding, including Royal Purple but not Redline. So in your case it's a matter of avoiding the grinding and figuring out whether you like shifting with Redline more than you like shifting with Royal Purple. Switching from RP to Redline should not cause any problems.

 

Thanks for the reply. I read that thread and thats why I want to try redline. They say that rp stops grinds and protects better and its 150% true. My friends trans has a had a horrible unavoidable grind when shifting into 3rd since the day he bought it. He changed to RP2 days ago and it has been silenced.

As a matter of convience Im putting RP back in tomorrow but I might try a 50/50 mix of redline and rp in the next few weeks.