2025 3.0L SO - Break In Period?

[Dusty19]

Do you sit in traffic often in AZ? I live a few hundred miles from AZ on a generally flat plain, but rarely sit in stop-and-go traffic. My average MPG is 17.8 (right now), but I drive like I have an open cup of coffee on the dash most of the time.

Nice! My wife drives the truck (it’s hers) and she does idle dropping kids off at school and picking up, but I’ve never seen a vehicle drop MPG so fast from small amounts of idle… maybe I’m just ignorant, but in all the years of me, owning and driving trucks, I honestly have never seen MPG drop as fast as it does on this truck just from 5 to 10 minutes of idle time.

She also drives like a little old lady. For the most part she stays out of the turbos.

I’m taking it into the dealership for some scheduled maintenance and I’m gonna have them check up on everything to make sure there’s no issues. Truck runs and drives perfectly fine so I’m not too concerned. Really just kind of baffled at how low the MPG is on this thing with absolutely no lift, no tires, no modifications whatsoever.

 

[Dusty19]

Oddly enough, I did an experiment a month ago, where I started accelerating fairly heavy from dead stops to quickly get up to posted speed limit and then let off the gas and would let the truck shift all the way into eighth gear and kind of just coast for as long as I possibly could. Doing this actually increase the MPG anywhere from .5 to 1.5 mpg depending on how far I could lug the truck in low RPMs in eighth gear.

You would think that flooring it from a dead stop repeatedly, and spooling both turbos at full psi would significantly decrease the MPG, but it had the opposite effect.

Then, after a few weeks of doing this, the numbers kind of fell flat and I was getting roughly the same as when we drive it like a grandma. So overall, no matter how we drive it or what we do we’re right around the 14–14.5 mpg range.