Best drive mode while towing with PB

[ryanryan]

I'm towing a 6,000 lbs travel trailer with my PB. Is it always best to be in tow driving mode? When I'm towing in stop and go traffic, tow mode will never allow electric driving. Maybe it's best to leave it in normal or eco mode in low speed/low power situations. The manual indicates tow mode changes shifting behavior but not sure this matters much at low speed.

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[F-150 Prius]

Electric mode is not the same as Hybrid mode, but in all modes, the electric motor is assisting the gas engine and drive train to improve its performance (power, torque, shifting, regenerating braking to capture inertia and return it when needed.)

I wish Ford offered the "normal" EV buttons (electric-only, charge battery to 100%) to let the driver control the behavior of the hybrid components. I'm assuming the product management folks decided to make the Hybrid mostly invisible and probably found that no matter what the driver does, the actual performance is about the same.

I haven't done much towing with the F-150 Prius, but I could envisage switching to Eco mode to let it turn off the engine if there was a long downhill.

Otherwise, I want to be in tow mode for the transmission shift logic and for the vehicle systems to "know" the job at hand (in terms of cooling, braking, stability and traction control.)

So "best" is indefinable. Some might choose to eke out an extra mpg "hypermiling" or staying at 55 mph. I bought the F-150 Prius as a distance monster, not a towing mule.

I wish Ford had put a 10 kWh or larger battery and 100 hp electric motor (like the Lincoln) and maid it a plug-in hybrid, but that's just too difficult a thought to bring to the bean counters trying to sell a million F-150 Lightnings.

So when I tow – maybe 5-10% of the miles I will cover in this truck – I know I give up diesel mpg and diesel is often the most expensive meal on the menu, so it's not necessarily a cost per mile deficit, but for 90% of my driving, I'm happy with an engine that shuts off while parked and the AC stays on, and there's a satisfying answer when I push down with the right foot.

 

[Sentinel1201]

I have done about 1500 miles towing a 4K trailer with my PB so far. Here are my learnings:

1. I manually lock out gears 8-9-10 while towing. Makes a huge difference as it doesn’t downshift from the overdrive gears and dip into boost. Stays in 7th pretty much the whole time and revs at 2600. I get 2-2.5 mpg better this way (around 12 for my load in Texas).
2. I leave it in normal mode around town and till I get on highway. When on highway, I switch to tow-haul since that uses engine braking more as well as calls on sway control. Saves the brakes in the long run.
3. I use the 7.2KW generator to power my trailer (15k BTU AC, Keurig, microwave, etc.) and other appliances. Get the 240V to 120V adapter, and use that as well as the 120V outlet right below it and it splits it between the two 3600 watt banks evenly.
4. I do fill up with premium when I’m towing, but thats something I have always done.
5. Make sure to install the pro trailer backup sensor on the trailer. They don’t use the stickers anymore and the hardwired sensor is so much better.

 

[BRDVPRA]

I have done about 1500 miles towing a 4K trailer with my PB so far. Here are my learnings:

1. I manually lock out gears 8-9-10 while towing. Makes a huge difference as it doesn’t downshift from the overdrive gears and dip into boost. Stays in 7th pretty much the whole time and revs at 2600. I get 2-2.5 mpg better this way (around 12 for my load in Texas).
2. I leave it in normal mode around town and till I get on highway. When on highway, I switch to tow-haul since that uses engine braking more as well as calls on sway control. Saves the brakes in the long run.
3. I use the 7.2KW generator to power my trailer (15k BTU AC, Keurig, microwave, etc.) and other appliances. Get the 240V to 120V adapter, and use that as well as the 120V outlet right below it and it splits it between the two 3600 watt banks evenly.
4. I do fill up with premium when I’m towing, but thats something I have always done.
5. Make sure to install the pro trailer backup sensor on the trailer. They don’t use the stickers anymore and the hardwired sensor is so much better.

The latest OTAs do allow you to use the stickers now!

 

[hussar1683]

Not to hijack the thread but I also have a towing question. Is it safe to tow with the new PB about 700-800 miles on it? It would be a light boat about 2,500 to 3000 lbs over a distance of 1,000 mostly flat miles. Should I try to put some more miles on it before the tow? Use premium?

 

[Cobraman428]

Not to hijack the thread but I also have a towing question. Is it safe to tow with the new PB about 700-800 miles on it? It would be a light boat about 2,500 to 3000 lbs over a distance of 1,000 mostly flat miles. Should I try to put some more miles on it before the tow? Use premium?

The Owner Manual states 1000 miles before towing.

BREAKING-IN
Your vehicle requires a break-in period. For
the first 1,000 mi (1,600 km), avoid driving
at high speeds, heavy braking, aggressive
shifting or using your vehicle to tow. During
this time, your vehicle may exhibit some
unusual driving characteristics.

 

[daemonic3]

I think Tow Mode is great - it is a "set it and forget it" easy mode that will do the right things for the truck and engine so you have instant power when needed (from a stop), locks out the upper gears, and will still use the electric motor assist and recapture from braking. The only thing I would interfere with manually is sometimes it will sit in 8th with a little boost, which sucks more gas than if you use 7th at higher RPMs with no boost.

However, for a Powerboost, I like to think of Normal as "expert mode" for towing. If you do the lockouts and constantly monitor the boost meter in the gauge cluster, you can optimize another ~0.5-1MPG on a decent length trip, and definitely >1MPG on surface streets, especially if there are long lights. I fully take advantage of the computer's ability to optimize when using adaptive cruise, and on the downward side of rolling hills Normal mode will allow shifting into 9th and 10th and sometimes brief electric-only spurts. You can see the way allowing 8/9/10 really help the instant fuel economy by watching it in your cluster.

I mentioned elsewhere before that I was shocked and pleasantly surprised that even in Normal mode on downhills, it will still kick the ICE on for engine braking as needed! I had lots of opportunity to test the modes and watch the battery charge % using Torque last time I descended from 7200ft to sea level. Once the battery reaches ~70% it won't charge anymore anyway so it's cool the engine kicks on to help so you aren't using pure friction on the trailer brakes. When the grade lessens and wind drag matches speed again the ICE will kick back off for pure electric again on the descent. On Eco Coach meter the regen bar is still green and you can check the trailer brake gain bars to make sure it isn't riding the trailer brakes while in the regen zone.

I should note that even in "set it and forget it" tow mode that it can ride your trailer brakes regardless, and to check if at a steady downhill speed that the gain is not lit up for extended periods. Cycling between applying brakes and letting it coast back up to speed again at least prevents the continuous trailer friction that we can get tricked into forgetting about on these powerboosts.

 

[UGADawg96]

I should note that even in "set it and forget it" tow mode that it can ride your trailer brakes regardless, and to check if at a steady downhill speed that the gain is not lit up for extended periods. Cycling between applying brakes and letting it coast back up to speed again at least prevents the continuous trailer friction that we can get tricked into forgetting about on these powerboosts.

Are you saying that when the PB is going downhill and using regen braking it is applying brake gain to the trailer even though the driver isn't using the brake pedal ? Would the driver see this in the instrument cluster somewhere ?

 

[daemonic3]

Are you saying that when the PB is going downhill and using regen braking it is applying brake gain to the trailer even though the driver isn't using the brake pedal ? Would the driver see this in the instrument cluster somewhere ?

Yes! I first tested it when I had my heavier 2800bh trailer and I started with gain set to 8.0. That's when I tested the operation of it, when I was still only using Tow Mode. Even if you are in regen zone on the truck, it can apply gain (friction) on the trailer. You can use the cluster menu to back out of ev coach, go to trailer settings, trailer status. It should have the brake gain meter showing live.

Of course this will vary with slope, speed, and gain setting but it's something to be aware of!

 

[UGADawg96]

Yes! I first tested it when I had my heavier 2800bh trailer and I started with gain set to 8.0. That's when I tested the operation of it, when I was still only using Tow Mode. Even if you are in regen zone on the truck, it can apply gain (friction) on the trailer. You can use the cluster menu to back out of ev coach, go to trailer settings, trailer status. It should have the brake gain meter showing live.

Of course this will vary with slope, speed, and gain setting but it's something to be aware of!

Thanks, I'll need to check that out. Can trailer gain be added to My View ? I don't recall. If not, it just makes it that more unsafe to be toggling the menu when towing. I usually leave the screen on tire pressure, but maybe I should watch the gain screen. Oh, and I've never really used the ev coach. Thanks!

 

[EricR]

When towing with our PB I use Eco mode in-town and on flat highways and freeways to add a few electric miles to our trip. When in hilly or mountainous areas I use Tow/Haul mode for the more aggressive engine braking.

Using the boost gauge I will monitor the boost and manually downshift to reduce it. When in the mountains here out West I have manually downshifted as low as 5th gear. Then on the downhill, as the boost goes to zero I will pop it back up to 10th gear and let the truck take over again.

Also, I noticed on downhills the gauge for instantaneous fuel usage goes all the way to the right. I assume this means the fuel injectors have shut off, and even though the truck may downshift for more engine compression to moderate speed, the truck is using zero fuel. Kinda cool!

-Eric

 

[daemonic3]

When towing with our PB I use Eco mode in-town and on flat highways and freeways to add a few electric miles to our trip. When in hilly or mountainous areas I use Tow/Haul mode for the more aggressive engine braking.

Using the boost gauge I will monitor the boost and manually downshift to reduce it. When in the mountains here out West I have manually downshifted as low as 5th gear. Then on the downhill, as the boost goes to zero I will pop it back up to 10th gear and let the truck take over again.

Also, I noticed on downhills the gauge for instantaneous fuel usage goes all the way to the right. I assume this means the fuel injectors have shut off, and even though the truck may downshift for more engine compression to moderate speed, the truck is using zero fuel. Kinda cool!

-Eric

Yep! Sounds like you enjoy towing in "export mode" as well, very cool!

 

[KDPGame02]

Yes! I first tested it when I had my heavier 2800bh trailer and I started with gain set to 8.0. That's when I tested the operation of it, when I was still only using Tow Mode. Even if you are in regen zone on the truck, it can apply gain (friction) on the trailer. You can use the cluster menu to back out of ev coach, go to trailer settings, trailer status. It should have the brake gain meter showing live.

Of course this will vary with slope, speed, and gain setting but it's something to be aware of!

Fascinating. I had no idea, and will look when we tow next week.

 

[BRDVPRA]

Not to hijack the thread but I also have a towing question. Is it safe to tow with the new PB about 700-800 miles on it? It would be a light boat about 2,500 to 3000 lbs over a distance of 1,000 mostly flat miles. Should I try to put some more miles on it before the tow? Use premium?

Always tow with premium. What does the manual say about the break in?

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