In this episode of "The Straight Shift", The Car Chick explains what is meant by the octane number of gasoline and why it's critical to use the right type of gas in your vehicle. Does using Premium gas give more power or better gas mileage?  Is it "better" for your car?  The Car Chick dispels many of the myths around gasoline to save you money. She also talks about the difference between regular gas and diesel and why it's disastrous to put diesel fuel in a gas engine and visa versa.