Gas

Is it just me, or does gas seem to burn faster the more expensive it gets?  My car usually gets about 309 miles out of one tank of gas.  Except when gas prices go up.  Y'all I think it is a conspiracy.  I think they either make the gas more flammable or find a way to make it burn faster.  I know here in Atlanta last year our gas shortage was caused by us running out of the low sulfur gas.  Maybe sulfur makes gas burn slower.