Top 10 Most Fuel-Efficient Pickups in 2023 Published on September 2, 2023 in Top 10 by Guillaume Rivard Photo: Fiat Chrysler Automobiles 3. Jeep Gladiator EcoDiesel 3L 6-cylinder diesel engine, 4x4 Combined fuel consumption: 9.8 L/100 km (Rubicon: 10 L/100 km)