admittedly most of that was highway mileage, but it wasn't like I was going 55, more like 70-75, either way, I didn't want to give credit solely to the magnaflow (which may in fact be the case) b/c I knew I was driving even more gingerly now that the freer (??) flowing muffler is on
I also changed front and rear axle fluids, which is seeming to be a joke compared to my transmission fluid change ordeal...