engine performance and 80 mph
Senior Member
Joined: Jun 2013
Posts: 401
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From: Utah
My Eco 3.5 has two different personalities.
With cruise control on, the ECU prefers boost over RPM to make HP, so no downshifting.
With cruise off, it seems to lean more toward RPM, maybe to give a more NA feel to it when driving under manual control.
With cruise control on, the ECU prefers boost over RPM to make HP, so no downshifting.
With cruise off, it seems to lean more toward RPM, maybe to give a more NA feel to it when driving under manual control.
Member
Joined: Nov 2012
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question!
When you say downshifting; you are referring to going from OD to a lower gear? I'm asking because read for my 2000 f150 5.4, while towing, you should disable the OD (by pressing the button on the drive selector).
When you say downshifting; you are referring to going from OD to a lower gear? I'm asking because read for my 2000 f150 5.4, while towing, you should disable the OD (by pressing the button on the drive selector).
Senior Member
Joined: Jun 2013
Posts: 401
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From: Utah
If I remember correctly, the new 6-speed actually has two gears that are "overdrive". It no longer has a button to turn off overdrive but rather a button for "tow/haul" mode that will keep the torque converter locked as much as possible. This favors a locked lower gear at a higher rpm over an unlocked higher gear to keep tranny temps lower at the expense of MPG (that's how I understand it after lots of towing, but I welcome enlightenment if I am wrong).
Having towed a bunch with a first gen 5.4 with 4-speed, that 5.4 would have fared far better with the new 6-speed. There were many times in the Sierra Nevada's that after a 10 mph hairpin turn that the jump from first to second was too big and I got stuck in first till the incline reduced a bit.
Having towed a bunch with a first gen 5.4 with 4-speed, that 5.4 would have fared far better with the new 6-speed. There were many times in the Sierra Nevada's that after a 10 mph hairpin turn that the jump from first to second was too big and I got stuck in first till the incline reduced a bit.
Last edited by frieed; Jan 9, 2015 at 09:38 PM.
Senior Member
Joined: Apr 2010
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If I remember correctly, the new 6-speed actually has two gears that are "overdrive". It no longer has a button to turn off overdrive but rather a button for "tow/haul" mode that will keep the torque converter locked as much as possible. This favors a locked lower gear at a higher rpm over an unlocked higher gear to keep tranny temps lower at the expense of MPG (that's how I understand it after lots of towing, but I welcome enlightenment if I am wrong). Having towed a bunch with a first gen 5.4 with 4-speed, that 5.4 would have fared far better with the new 6-speed. There were many times in the Sierra Nevada's that after a 10 mph hairpin turn that the jump from first to second was too big and I got stuck in first till the incline reduced a bit.
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Senior Member
Joined: Jan 2012
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From: Northern CA
In the situation of the OP any engine, other than the 3.5 n/a, will be better than the 5.4 in those conditions. Get the lowest numerical gears to make it feel better. I'd suggest 3.55 gears for the 3.5 ecoboost and 3.73 gears on the rest. If you get the 5.0 with 3.31 gears you are more likely to experience down-shifting so I would steer clear of that combination. Keep in mind the 15' 5.0 makes more low end torque than the outgoing 14' 5.0 due to changes in the top end of the engine.
Yes, in those conditions the turbo vehicles can make more torque than the 5.0 but at the expense of fuel economy, usually.
I also suggest you avoid larger tires and leveling/lift kits and they will be more affected by the speed and headwind.