Hemi 5.7 3.92. Will gas mileage improve after break in period? If so how much can I expect? Is there a proper way to break the motor in? Thanks for your help. That 3.92 has some *****, definitely throws you back in the seat.

 

Break it in like the manual says - and be nice to it for the first few thousand miles. Mechanical stuff appreciates that.

Use good quality oil, I like full synthetic.

My mileage improved about 10-12% around the 5,000 mile mark.

 

Depends where your driving your vehicle...if your up north the gas stations probably started putting winter fuel in and you gas Milage will drop a bit...it won't improve to much, remember its a truck..Dodge say 20mpg, that's Hwy no wind half a tank doing 60 MPH...in the city you'll watch your MPGs drop. But I bought a truck not a Prius ...

 

It will never be "good" MPG so don't expect any miracles.

 

Good is relative - anything over 20MPG in a full size truck, is good mileage - even on the road. Expect 14-16 in town driving. I regularly get 21-24 on the road, and about 16-17 pulling my 2000 pound boat.

 

I have a regular cab 2010 hemi w/ 3.92. The EVIC mileage I get is 13/17 and I have on/off road tires. I have 5900 miles, and the mileage I get has been the same as day one.

 

didnt notice any change. just pull in the station and bend over

 

Not trying to sound llike a dick in anyway, but why did you buy a truck then?

haha..

 

I can't believe those that say nothing improved! MHO

I could feel it get more responsive, get more loose and willing to rev, and yes - mileage did improve! Not a huge change, but change nonetheless. Even on paper

 

Never really noticed a difference in milage, its got 55K on it now.