Originally Posted by chops

i also run penzoil ultra 5w/30. however, ive noticed that once you hit the 220 degree range, the ECU starts to pull timing. you can definitely tell there is some lost power. its not limp mode, no thats at 260 degrees, but there is definitely something different going on at 220 degrees. since installing the 25 row this weekend, temps stay in the 180-190 range and its MUCH better