Average on a full tank. And ive been playing with the added power as well. 2021 Chevy Colorado Extended Cab Prices Reviews And Pictures Edmunds Going for the diesel brings that down to 18 city, 22. Chevy colorado gas mileage diesel . 24 miles per gallon highway; The estimated change shows the fuel economy will go down to 1 mpg if the air dam is removed. 28 miles per gallon highway We recently received this question at ask@tfltruck.com from jesse g. The 2021 chevrolet colorado diesel gives fuel economy numbers of 20 mpg in the city, 30 mpg on the highway, which is more than the regular version of colorado. Use our handy tool to get estimated annual fuel costs based on your driving habits. 19 miles per gallon city; The chief engineer said that it may be okay to remove the air dam, but there will be a significant change to the car’s fuel economy. 19 miles per gallon combined; 17 miles per gallon city; 2015 chevy colorado, gmc canyon gas mileage: View all 202...