Top 10 Most Fuel-Efficient Compact SUVs in 2022 Published on February 20, 2022 in Top 10 by Dominic Boucher Photo: General Motors 9. GMC Terrain Under the hood of the Terrain is a turbocharged 1.5-litre four-cylinder engine mated to a nine-speed autobox. FWD-equipped models need just 8.6 L/100 km on average.