It's mostly driving conditions. 0177 got about 15mpg when new, and by the time it made it to 35k miles, I was regularly getting 18-19 mpg average. My Nittos are oversized at 255/18, but really, the way they fit, it's the size that the car should have had stock.
Now at almost 50,000 miles, I'm averaging about 19mpg..............**it is very flat and smooth here. Going at speeds greater than 6omph greatly affects milage, and at 75 or 80mph, I'm seeing 14, 13, and even less
It's livable as long as I don't push