If gas was $.22 a Gal and Kerosene was $.16 a gal you ran the cheaper. Getting them started was the hard part left to the Gasoline. Once running and heat had been built up switch the cheaper fuel. I worked for a dairy farmer in my youth and he used 40 Watt light bulbs until the dairy inspector was coming. Then we switched them out for 100 watt bulbs until he left, then back to the 40 watt. Pinch a dime hard enough to get 11 pennies out of it.