Nice post kcROB, I've used the 5-30 mobil 1 synthetic mostly when I find it on sale, didn't know 5-40 was acceptable. So the 26.2 is a lifetime average, correct? I just did a road trip and without calibrating my odometer got 32.7 usmpg which was all gentle highway driving. So I figga say the odometer is off by 10% thats still 30mpg... given city driving, flogging, etc, that number looks like perhaps what my car might be getting too. Done yakima to yuma many times, hope to get out there for a road trip again some time.