Poor fuel mileage after moving to Arizona from Indiana

Couple things. First, I would challenge you on the 400 down to 200. A lot of times what we do is generalize our distances. Meaning there may have been times when you went 400 miles on a tank of fuel but there were also times when you did different types of driving and only went 350 miles on a tank. Then I understand you feel like you are only going 200 miles on a tank now but there are times you go 250 miles. So in general there is a difference between the two but it may not be cut in half. That sounds a little drastic. So let's write down the mileage at the next fill up and see what it is when you fill up again and how much is left in the tank.

The other idea that the fuel quality is lower is not true. I assume they are talking about octane levels. This is not a rating in quality. This is a rating on the ability to combust in the engine without causing spark knock. So the higher the altitude the lower the octane rating needs to be to achieve this. So you actually get better fuel mileage in higher elevations but lower performance.

Lastly, if you are driving in short distances and stop and go traffic, that is when you get the worst fuel mileage. If you think about it, your miles per gallon is figured by how much distance you travel per gallon used. So if you are not driving far and idling a lot then your distance is not going to be far. If you are driving much different, I would not worry about the distance per tank but look at your fuel cost per month. I would expect your fuel cost to be about the same or a little better if you are not driving as far in AZ.

Does that make sense?

Okay. That is good to know. So I think you are correct that driving style and adding the A/C will account for the drop. It does seem a little much but if you are going longer between fill ups then I suspect it is accurate. Thanks for the update.