I did a little experiment on a full, mid and empty tank of gas in my 2014 Mustang GT. With a full tank I get .53 g force in second gear. Then 3/4 I get .54. Then 1/2 tank I get .55. With a 1/4 tank is .56 and almost empty it's .57. I believe it's 5 lbs per gallon and 4/8/12 and 16 gallons is 20/40/60 and 80 lbs. So it does make a difference.