Good morning ya’ll.
I remember that there was some discussion that the torque on the 5.0 didn’t come on until 4Kish rpm. Yes and no, Peak torque doesn’t come on until then. But there is plenty of usable torque In the lower RPM range.
I was looking around for some tunes a while back and here you go.
5.0 stock and stock tune.
View attachment 740587
3.5 EB stock and stock tune Compared to the perf tow tune.
View attachment 740588
I you you look closely both are at almost 300 ft pounds at 2.5k RPM. So not really that big of a difference for low down torque.
At this point pick your poison.
That is a pretty bad representation of the Ecoboost torque curve. They rolled into the throttle starting at 2200 rpm and were not fully in it until 3000 rpm. They probably did it to control the torque surge that would happen due to being in a high gear at high load at low rpm. I've never seen a 2nd gen 3.5 official torque curve, but the first gen 3.5 was making a peak of 420 ft-lbs at 2250 RPM, and 90% of its peak torque was available from 1700 to 5000 rpm. So that means at 1700 RPM it was making at least 380 ft-lbs.
The current 3.5L is rated for 500 ft-lbs at 3000 rpm.
You would need to put them on a load dyno that holds the engine at a certain RPM to see the true difference in torque produced. There is a huge differnce between steady state torque(like towing a trailer up a mountain at constant speed) vs acceleration(like on a typical dyno.) The Ecoboost demolishes pretty much any other half ton motor at 2000 rpm or less with the exception of maybe GM's 6.2L
Here is the torque curve for the 1st gen 3.5:
I have the same problem with those HP/torque curves as with most others I've seen...they start at 2000 rpm and seem to show the vehicle has NO power below that. My truck spends 99.9% of its time below 2000 rpm even when towing, so show me what the engine is producing from idle to 2000 rpm. I could care less about anything above that range.
Exactly.
Well I don’t know about the 99.9% below 2K. Ya’ll must have low speed limits there and towing lite.
My 2014 3.5L tows a 6000 lb travel trailer with the aerodynamics of a parachute in Utah where the towing speed limits are 80 mph. I usually tow at 70mph but have done 75mph on some occasions. My ecoboost will chug along in 6th gear at 1900 rpm no problem with LT315/70R17's, and that is at 6500' of elevation where a 5.0 would be gasping for air and making 20% less torque.
Climbing 7% grades is done at 3200 rpm at that speed. So basically my Ecoboost spends 95% of its time towing at 2000 rpm or less, with the occasional jump to 2500(5th gear) or 3200(4th gear) on climbs. And thats stock. With a tune mine was climbing 2-3% grades in 6th. The newer Ecoboosts make 60 or 80 ft-lbs more torque and would need even less RPM on the climbs.
Thats the difference between a 5.0 and 3.5. That dyno graph doesnt tell you anything meaningful because it doesnt even show the reall torque numbers in the RPM range the truck would even be at towing. 3000 rpm is the highest the truck would really need to be at unless you are towing an absolutely massive load up a 7% grade.
Even my MIL's 7.3L Godzilla was less torquey than my 2014 Ecoboost at low RPM.
