A system includes a sampling module and a map generating module. The sampling module receives a first mapping of thermal efficiency of a spark-ignition engine generated based on operation of the spark-ignition engine with a dynamometer. A combustion chamber of the spark-ignition engine has a first compression ratio. The map generating module generates a second mapping of the thermal efficiency of the spark-ignition engine based on the first mapping and the combustion chamber having a second compression ratio. The second compression ratio is different than the first compression ratio.