How To Figure Compression Ratio

Also unfortunate is the variance of 93 pump gas from station to station in any area.

My buddy hauls gas and on occasion will dump regular into the premium tank if after topping off the regular tank and there is gas left in the truck. They drive that truck till every station on their route has gas no matter how long it takes. He is a relief driver on Sundays and its a long day, 12 hours or more.
I have a friend who's driven a gas truck here in Georgia for 30 plus years and he's told me before you can get put in JAIL and companies fined huge fines for doing what you describe.