Ecoboost 3.5 Towing MPG Sucks
Hi all, back after a couple years without a RV......I jumped back in with a Passport Ultra Lite 153ML, GVWR of 4500lbs. I just returned from picking up the trailer and pulled it with my 2017 F150 3...
Forum Discussion
ppine wrote:
It is counter intuitive, but larger diesel trucks solve all of these limitations. A 3.5 liter engine has to work hard to pull. That generates heat and uses a lot of fuel.
The Ford 7.3 liter is not working hard at all towing 4,500 pounds. It gets much better mileage than a 3.5 liter gas engine and will last twice as long.
This is incorrect.
It's not an issue of the engine working hard. In fact for the power developed, working an engine relatively hard (but not flat out) is usually more efficient per HP generated. Running at very light loads is less efficient (hence why you see little 4 cylinder engines in small cars rather than big V8's).
The difference with your 7.3 is primarily because diesel engines are more efficient...this comes from using higher compression longer strokes extracting more energy from each explosion...diesel containing more energy per gallon...also your older 7.3 doesn't have some of the newer energy robbing emissions controls
