Quote Originally Posted by MetroAveo
I've been trying to figure out my mileage for awhile now, and so far the results have varied greatly. My driving is a mix of city and highway driving, but mostly highway. I accelerate slowly, shift at exactly 2K RPM, and coast for long distances whenever possible. I will even coast with the engine off sometimes. So far my calculations have been: 36 MPG, 38 MPG and once I even reached 40 MPG. But lately it has dropped back down to 36 MPG and it won't go any higher. I haven't changed my driving at all, and I rarely use the A/C. What could be going on? Does it help to shift really soon, or is it best to "burn and coast"?
Maybe the gasoline is a summer blend now. I think they oxygenate the gas in the summer or something, that makes the mileage worse, but 36 really isn't anything to complain about.