They’re playing games with AFUE ratings 95% of 91,500 btu is less than 85% of 138,500
Propane: 91,500 * 0.95 = 86,925 effective BTUs per gallon
Heating Oil: 138,500 * 0.85 = 117,725 effective BTUs per gallon
To do an apples-to-apples comparison, look at how many gallons of propane are...