I just got this email from my brother

When I went on vacation a few weeks ago, I filled the tank up with regular, which is what I always run in my cars. The first time I stopped was just past Savannah, Ga and I was getting about 19 miles per gallon. I decided to fill up with premium and the next time I filled up (in VA) I was averaging 23 miles per gallon. I kept filling up premium until I got back to Savannah, and then filled up with regular again. Same results with the regular, 19 MPG. I know I’m getting better mileage with the premium, but it also costs more ($4.87 vs. $4.45) per gallon. Is it worth paying .42 more per gallon in order to get 4 more miles per gallon??

Bro, bless his heart, is sharp as a whip, and is a college graduate (history). But shouldn’t he be able to do this kind of problem?

Then again, he drives a BMW and I drive a Sentra. That alone should tell you something. Maybe I should fill up with premium next time I go up the line.