So the other day (and in the wrong thread) some people were talking about MPG loss due to "winter mix" fuel. Not sure the validity of this but I have noticed a 2 MPG drop over the last month or so. Well yesterday I bought Mobil gas and I noticed today my mileage is back up to mid 17's where it used to be...
Does anyone know if different companies use different additives/winter blends etc...? I know they all say their formula is the best and I remember reading a study that Shell had the "best gas" but what do you all think? Or was I just driving like a masshole for the past month...?