Miserable Towing Experience - NEED HELP! (Updated)

[bowenzhang]

That’s a lot of drag there with the cabin on the boat.

and yea, 65mph is too fast. I just towed my 6000lbs airstream this weekend and got 760wh/mi. I tow at 55-60mph with very conservative accelerations.

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[langenbahn]

Summary:

1. Slow down to 60MPH
2. Inflate tires to 65PSI
3. Ignore middle fingers.

I appreciate all the observations! Will give it a try in September.

 

[RidnDirty]

Those tips seems great along with keeping on CHILL/LOW/ in custom while avoiding cruise may be best. Cruise doesn't seem to re-gen much if any while CHILL seems to cut back on a/c and probably some other things usage savings. I noticed in traffic the other day, the truck hardly used much power as it was re-gen quite a bit.

 

[Cyber Man]

Summary:

1. Slow down to 60MPH
2. Inflate tires to 65PSI
3. Ignore middle fingers.

I appreciate all the observations! Will give it a try in September.

one more very important thing - lower your expectations significantly (at least 80%) when towing a parachute (as @CyberGus rightly said) during long road trips ?

 

[TyPope]

TLDR: Trailer brakes can take away from regen capability.

Trailer brakes are tricky with EVs. You want the trailer brakes to "Lead" the towing vehicle typically because you don't want to be slowing down and having the trailer push you. Unfortunately, EVs are more efficient when THEY do all the slowing through Regen.

The double-edged sword is that in order to tow safe, the trailer brakes should slow the trailer (and thus impart some slowing force on the tow vehicle) at a rate that slightly exceeds the tow vehicle.

The problem is if the trailer brakes are too quick to slow the tow vehicle, you lose a lot of regen. The trick is to get an almost balanced brake application. The trailer should be neutral... basically, the truck should slow down the same WITH the trailer as without.

Sometimes when towing with my F-350, the trailer will be heavier than I'm set up for and I can feel the trailer pushing me as I slow down. That's not good. Ask my wife what it's like to have a trailer whip you around while you are trying to slow down... She loved that truck (RIP. The wife's fine. The Explorer, not so much). While that's not good for a regular truck to have the trailer push, it would actually benefit an EV regen as the extra mass would allow for more regen... until the trailer starts swinging side to side!

I've also seen the other way where the trailer brakes are set too strong, and I've actually had the tires lock up as I approached a stop at normal deceleration. Not only does that wear out the trailer brakes but it steals regen from the towing vehicle.

 

[firsttruck]

Can the canopy roof be easily removed and installed before launching boat?

"aerodynamic cover" for "center console boat" might help.

-----------------------------------

Waterproof Center Console Boat Cover 20-22ft, Heavy Duty 1300D Marine Grade Polyester Canvas Covers, Color: Gray
https://www.amazon.com/BOATPRO-Waterproof-Console-20-22ft-Polyester/dp/B0C33GZLMQ

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[langenbahn]

Unfortunately, the center console is a integrated piece of the boat.

 

[MeadowShade]

I had a boat similar to yours when I had a Dodge Durango SUV. I got 5-7 mpg trying to go 70. That improved to 10-12 mpg staying below 65 mph.

Now I have a CyberTruck and no boat but I do have an aero correct camper 21' and a 16' car hauler box trailer.

I just towed the camper 1,000+ miles and was at 602 watts per mile. It is about 3,200 pounds and a good shape for towing. I drove the speed limit the entire trip.

BUT, my BOX car hauler ... empty or not ... is always 800 - 1,000 watts per mile and to get it down to 800, there has to be no headwind and 60 mph or less.

AERO makes MORE difference than weight! If you could put a slick boat cover over the boat, that could help, or take the windshield out ... it is blunt on the front and a big vacuum on the back side. That is why by car hauler sucks so bad. It is big flat vacuum on the back door.

This of it this way ... the CT has about 600 hp. Towing it 65 or 70 probably takes 300-400 hp and you lose any regen help because the wind drag slows you down first. Towing below 60, you are probably only using 150 or 200 hp. In fact, on the non Beast, only the rear motor is being used and IF you can get to that level of drag, the efficientcy goes way way up!

 

[mongo]

I had a boat similar to yours when I had a Dodge Durango SUV. I got 5-7 mpg trying to go 70. That improved to 10-12 mpg staying below 65 mph.

Now I have a CyberTruck and no boat but I do have an aero correct camper 21' and a 16' car hauler box trailer.

I just towed the camper 1,000+ miles and was at 602 watts per mile. It is about 3,200 pounds and a good shape for towing. I drove the speed limit the entire trip.

BUT, my BOX car hauler ... empty or not ... is always 800 - 1,000 watts per mile and to get it down to 800, there has to be no headwind and 60 mph or less.

AERO makes MORE difference than weight! If you could put a slick boat cover over the boat, that could help, or take the windshield out ... it is blunt on the front and a big vacuum on the back side. That is why by car hauler sucks so bad. It is big flat vacuum on the back door.

This of it this way ... the CT has about 600 hp. Towing it 65 or 70 probably takes 300-400 hp and you lose any regen help because the wind drag slows you down first. Towing below 60, you are probably only using 150 or 200 hp. In fact, on the non Beast, only the rear motor is being used and IF you can get to that level of drag, the efficientcy goes way way up!

600 Wh/ mile * 60 MPH = 36kW * 1.34hp/kW = 48 hp.
100 hp = 75kW, at 75 MPH that's 1kW/mile.

 

[MeadowShade]

600 Wh/ mile * 60 MPH = 36kW * 1.34hp/kW = 48 hp.
100 hp = 75kW, at 75 MPH that's 1kW/mile.

Well ... there's the math. my Model A has 40 HP.

 

[mongo]

Well ... there's the math. my Model A has 40 HP.

Yeah, steady state is the (mostly) easy part, even at highway speeds.
Doubling speed is 4x the aero resistance so 4x Wh/mile (for that portion) and requires 8x the hp (due to twice the distance per unit time).
Hp also matters in terms of available torque which determines how fast you can accelerate at a given speed.

 

[MeadowShade]

Well, efficiency begins with the Right Foot!

 

[CybertruckRN1127]

I don’t tow, but I always see signs that says 55mph speed limit when towing. Maybe do 55mph, but your trip will probably still be 10-11 hours.

 

[MeadowShade]

In CA, that is the speed limit towing I think.

 

[Speedr]

Thanks for the pic. Great setup!

First comment on ride height. The ride height is different when it tow mode. It defaults to Medium, not Low! I was happy with that since I was towing locally, so I haven't tried changing it.

In regards to speed, it DOES make a huge difference. As others have said, the amount of energy needed as speed goes up is not 1 to 1, but exponentially (I'm sure I'm saying it in the wrong way, but you get the gist).

Inflating ALL of the tires to a much higher PSI will help as well.

The big, remaining change is Aerodynamics. I've had a few center consoles, and have had 2 different types of covers. A whole boat one (well, everything except the roof), and a center console one that just covered the center console and seat. If you don't own either, you could try and find someone that has a similar boat with a cover that you could try (i.e. tow their boat with and without the cover). The other option, before buying one, is to try and temporarily "wrap" your center console and seat (tape, plastic, cloth, etc.) and see if that makes any difference. Even the poles aren't great...

Also, the slower you go, the less aerodynamics play a role.

Really hoping a cover, or some are tweaks make a big difference. If you look at Bowlus travel trailers, you'll see how much more range they provide vs. a normal travel trailer. In that same vein of thought, you can also see others on this forum that post their consumption numbers pulling similar weighted Travel Trailers, which do a lot better.

Good luck, and keep us informed @langenbahn!

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