I just ran some numbers if regular cost $3.80/Gallon and Premium cost $0.20 cents more per gallon and if this increase your MPG by at lease 1.21 MPG I.E. 23 to 24.21 you will break even. If you get 15 with regular and 16.21 with Premium you will save 1.58 per tank using Premium. As the price of gas goes up the numbers get better at $4.25 for regular and that same $0.20 Adder you will save $0.36 per fill up if you get 24.21MPG over 23MPG and $2.11 if you get 16.21MPG over 15MPG. Just something to think about. Now the question is will the Bullitt get 1.21MPG more when we use Premium over Regular. The Bullitt might be one of the first cars where this is a possibility with its duel knock computer strategy.