I never thought an engine mileage can ever be increased by any means. Many people don’t have the idea that they can also increase fuel mileage on their 5.7 Hemi. It may be able to raise mileage, but you may need to use more than one gallon, and it adds up to the high cost. So, people tend to search for some techniques to boost up the mileage.

It is possible to increase the mileage with one gallon.you can boost the mileage up to 27 mileage per gallon on average, which was previously only 15 mpg.
By Reducing Resistances
By Stopping Lifting the Truck
By Using a Perfect Tires C
hanging Fuel Filter or Fuel
Using Cruise Control
Setting up an E-fan
Never Letting Engine Be Idle
Here are some more details regarding these techniques I got.
What are your opinions regarding this case?? Share your known ones.

 

I am going to call BS on this one. No way on god's little green acre are you going to convince a big heavy truck, with a v-8, to get 27mpg.

 

It's almost impossible to get 20 MPG. I agree on the BS.

 

You can barely get a 5.7 Charger to do that on the highway, it's a 1000lbs lighter and still requires you to use cruise control at 55mph and be completely stock.

 

my best is 18mpg imperial gallon

maybe with a diesel engine and imperial gallon...not with a gasser.

 

AKA the fuel rating for highway

 

believe it....it was downhill, drafting, with the wind towards a magnet factory.

 

20mpg Highway is doable. Saw 24mpg a couple of times. I used to drive 80 miles a day round trip to work (mostly highway) and averaged 20mpg on my 08 2wd 5.7L Quadcab with a 3.92 gear and 275/60R20 tires. It got the best mileage with a 93 octane tune (Diablosport Predator) and a Bed cover. Drove that route for about 3.5 years. Around town, I am getting 14mpg. I can't see 27mpg from these bricks at highway speeds.

 

Much less "average."

 

This is funny.