I'm planning to change my motor oil and tranny oil right after the break-in period which 1,200 miles. I will go with the mobil-1 synthetic and Redline for the tranny, but I am still confuse which Redline I should go with. There are 350 Z owners who recommand to go with 70W-80, but the manual says 70W-90. So can you guys just jot down what you're using for you car? thanks guys