I am planning on adding this tranny cooler to my truck for towing purposes and I already have Redline D4 ATF that I use in my Accord laying around. I was going to use this to add any additional fluid needed after the install. I assume it's safe to mix syntheric and non synthetic tranny oil from what I Have been reading. According to Redlines site this is also compatible with the Blazer however it states that MTL should be used with vehicles equipped with automatic transfer cases. I assume they mean in the transfer case and that D4 is fine for the transmission? Has anyone used this in the Blazer before? Any issues?

 

Well I spoke to Redline and they said the D4 was the correct fluid. I went ahead and used it when adding the tranny cooler.