F150 2.7 EB vs 5L V8 towing mpg

rjstractor wrote:

BenK wrote:
Then how many square inches per piston top...there in lies the answer to thermal limits to duty cycle...therefore the difference in tow ratings and the higher HP for the bigger NA engine

And likely the reason we yet don't see a turbocharged gas engine in a 25/35 series pickup. The 3.5 Ecoboost is in available in the Transit 250/350, but with lower power and tow ratings than the F150, and it's not available in cab/chassis models at all.

For speculation about what the 3.5 Ecoboost would do in any truck you should stick with data from trucks. The Transit is designed for carrying, not towing, and doesn't have the frame for towing.

I still don't feel like anyone has explained why turbocharging a gas engine is so much less effective than turbocharging a diesel. I will buy into the idea that 3.5 was not designed for Super Duty work but all the same I have not heard any reports of them not holding up to work within their ratings. Oh sure, I have heard rumors, mostly from people without first hand knowledge, but all the local shops I have asked tell me that they very rarely see any issues with Ecoboost engines in trucks.

As far as the discussion about combustion temperatures, that is mostly determined by inlet temperature and compression. Turbo's still have a slight rise in inlet temp even after the intercooler and that is dealt with by slightly lowering the compression ratio. This does lead to a slight loss in efficiency. For that reason a naturally aspirated engine can give a little better mileage under heavy load.