You are in California whichs uses alcohol as an additive to keep the air clean. What they don't tell you is that alcohol is less efficient than gasoline. Therefore the air is cleaner but you have to burn more to get that result. Kind of stupid?

Go up to Oregon and fill up, you will notice the difference!

The odometer is calibrated to read with the original diameter tires. If you have change that diameter, your mpg will change also. Bigger tire= lower odometer reading=lower mpg.

Don