Ecoboost engine question

Krusty wrote:

otrfun wrote:

goducks10 wrote:

otrfun wrote:

goducks10 wrote:
My guess is that the 3.5 is maxed out with the 11,300lb tow rating in an F150. Add the extra weight of the F250/350 and the 3.5 would have a hard time reaching the 15,000+lb tow rating offered with the 6.2. It works fine in it's own element.

The 3.5 Ecoboost has 15 lbs. more torque than the 6.2, not to mention the 6.2 develops max torque at a relatively high 4500 RPM vs. the 3.5 Ecoboosts's much lower, diesel-like, 2500 rpm. I would think the limiting factor (ref tow capacity) for the 3.5 Ecoboost F150 is the 1/2 ton drivetrain and suspension.

Concerns about the 3.5 Ecoboost duty-cycle and fuel economy aside, I believe the 3.5 Ecoboost's torque characteristics would provide much better realworld performance (to include towing) than a 6.2 in a F250/350 chassis. Torque does all the work. The 3.5 Ecoboost has more and at a much lower RPM than the 6.2.

IMO the 3.5 is maxed out for stress in the F150. Do you really think the 3.5 in a 7-800+lb heavier truck can pull a 15,700lb 5th wheel? Even in the HD F150 it's still 11,300lb max towing. And the HD F150 has payloads equal to the F250 in certain configs. So with your way of thinking the HD F150 3.5 should be able to tow 13,000lbs with the 3.5. Why didn't Ford up the tow rating in the HD F150? Just because it has more torque at lower rpms doesn't mean it's internals are up to heavier towing. Why would Ford waste their engineering money on building a 6.2 for their HD trucks if the 3.5 was up to the task.

In the context of this debate, I think you have to compare these two engines in the context of them using the same chassis and drivetrain. No, the F150 3.5 Ecoboost cannot tow 13,000 lbs. Why? Because the F150's 1/2 ton drivetrain and suspension won't support it, not because of the engine.

Would a 6.2 mounted in an F150 chassis support more tow weight? If you say, yes, than how and why? The 6.2 puts out less torque than the 3.5 Ecoboost. Torque tows trailers, not HP.

The 3.5 Ecoboost engine is designed to put out 420 ft. lb. of torque. The 6.2 is designed to put out 405 ft. lbs. of torque. IMO, torque is torque. Is 1 ft. lb. of higher displacement V8 torque somehow "better" than 1 ft. lb. of turbo-charged, V6 torque? If so, can you explain how and why?

The fact the 3.5 Ecoboost has more torque than the 6.2 is not even the real clincher. The real clincher is the fact the torque on the 3.5 Ecoboost is output at nearly half the RPM's of the 6.2. In the realworld this makes the 3.5 Ecoboost much more useful and desirable from a drivability perspective. This is why diesels are so, so addictive. This is also why the Ecoboost has been such a run-away success for Ford. The 3.5 Ecoboost does one heckuva fine job of emulating a diesel engine's torque curve.

For what its worth, the 6.2L in the F150 puts out 434 ft/lbs of torque

Which is why Ford detuned the Superduty version of the 6.2 for durability. Speaks to duty cycles expected from the f250/350 vs the lighter duty f150.