Driving hot rods with $4 a gallon prices--I love it, when I can do it

I buy 118 at the local refinery at a price that is approaching $70 for a 5 gallon can...... I then mix one gallon of the 118 octane with 5 gallons of 91 pump fuel. My engine drinks gas at about 4 miles per gallon on the city streets. It will approach 10mpg if I stay in the slow lane on the freeway.