With the price difference of standard transmission fluids vs. Redline products with respect to fuel economy saving and power transfer efficiency seems reasonable to use the Redline product as the return on investment would be very short . D4 vs. D6 differences as what I understand has a cold or warm climate operational range . And If I were to use a warm climate viscosity for better torque converter efficiency at the expense of shifting performance and component wear in cold climate conditions . Couldn't find any information including comparison charts

Any thoughts ?

 

I've used the D4 long time ago, but it was for a manual trans. Not sure about the D6..... Have you tried contacting Redline to ask them?