# Model 3 as an RV Toad



## garsh (Apr 4, 2016)

Definition: toad - _A car or other vehicle that is towed behind motorhomes for use when the motorhome is set up in a campground and connected to utilities. Also called a "dinghy." Fairly common in the United States and Canada, less common in Europe, it becomes a virtual necessity for owners of motor coaches stretching 40 or 45 feet, difficult to maneuver in places like supermarket parking lots.
_
People with large RVs almost always tow a small vehicle behind them for local use. Although you can use a dolly, and park the car's front tires on the dolly to tow them around, serious RV'ers prefer to "flat tow" - that is, all four wheels on the ground. It's simpler, but the car being towed has to be specially prepared to handle this.

An electric car would be the *perfect* toad. But it would require the manufacturer to create a toad mode to alter the behavior, in addition to the various mechanical changes required.

Attachment points on the front for the tow bar.
A wiring harness at the front so that the RV can activate the toad's brake lights and turn signals.
When the RV brakes, have the toad perform regenerative braking. Might as well charge the battery while also helping the entire rig to slow down.
Extra credit bonus points: use autopilot cameras when the rig is running in reverse to steer the toad's wheels to allow backing up the rig to actually work reasonably.
I don't think the toad market is large enough for Tesla to care about it, unfortunately. But if they were to update the software to include a "toad mode", I bet third parties would be willing to create the hardware modifications required. And then Teslas would be *the* vehicle that every RV'er would buy to use as a toad.


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## AEDennis (Apr 10, 2016)

garsh said:


> Definition: toad - _A car or other vehicle that is towed behind motorhomes for use when the motorhome is set up in a campground and connected to utilities. Also called a "dinghy." Fairly common in the United States and Canada, less common in Europe, it becomes a virtual necessity for owners of motor coaches stretching 40 or 45 feet, difficult to maneuver in places like supermarket parking lots.
> _
> People with large RVs almost always tow a small vehicle behind them for local use. Although you can use a dolly, and park the car's front tires on the dolly to tow them around, serious RV'ers prefer to "flat tow" - that is, all four wheels on the ground. It's simpler, but the car being towed has to be specially prepared to handle this.
> 
> ...


I'm not sure if Tesla would be designing the car in this manner, but I seem to remember someone doing something similar in a Leaf and discovered that they were charging the car as it was towed in that manner.

It was a YouTube from 2012 or 2013. I'll have to dig for it.


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## garsh (Apr 4, 2016)

AEDennis said:


> I'm not sure if Tesla would be designing the car in this manner, but I seem to remember someone doing something similar in a Leaf and discovered that they were charging the car as it was towed in that manner.
> 
> It was a YouTube from 2012 or 2013. I'll have to dig for it.


Yeah, I remember that video. It's blocked in the U.S. now for some reason.




An article w. some pictures: Can You Charge a 2011 Nissan Leaf by Towing it? Apparently So (VIDEO)


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## Michael Russo (Oct 15, 2016)

garsh said:


> Definition: toad - _A car or other vehicle that is towed behind motorhomes for use when the motorhome is set up in a campground and connected to utilities. (...) Fairly common in the United States and Canada, less common in Europe (...) _And then Teslas would be *the* vehicle that every RV'er would buy to use as a toad.


This creative idea from our friend @garsh inspires me two things...:

1. Maybe because I'm European, here I was all this time thinking a toad was this...









Or, at the extreme, having played a lot of Mario Kart with my youngest daughter on her Nintendo Wii years ago, maybe this:








So little did I know...! 

2. Sure could use a 'toad', and wouldn't it have been great for it to be a Model ≡ (!) as I drive from Acworth, GA to California & back late July!!


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## UncleMoose (Sep 28, 2016)

I sent an email to Tesla a year or 2 ago outlining many of the same points. At the time I was planning to retire (in a year or so from now) with an RV pulling my Model 3.

Now my thinking is that we should be able to put the Model 3 into "baby elephant" mode where it will follow the RV without any physical connection. It should be a logical extension of the Summon feature, where the Model 3 will just follow the RV at (say) 2 car lengths distance, mimicking any turn signals, flashers, brake lights, etc.

Granted, doing it this way will use the car's battery, but it should get pretty good "mileage" since it will be only needing to follow the acceleration and speed pattern of an RV. There might also be an aerodynamic advantage to drafting a larger vehicle.

Legally, you would still probably need to use tow chains for safety reasons, at least until autonomous driving is fully accepted.


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## garsh (Apr 4, 2016)

UncleMoose said:


> Granted, doing it this way will use the car's battery,


Yes, plus you miss out on the extra on-the-go recharging that you get by mimicking trailer brakes using regenerative braking.


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## chopr147 (May 23, 2016)

UncleMoose said:


> I sent an email to Tesla a year or 2 ago outlining many of the same points. At the time I was planning to retire (in a year or so from now) with an RV pulling my Model 3.
> 
> Now my thinking is that we should be able to put the Model 3 into "baby elephant" mode where it will follow the RV without any physical connection. It should be a logical extension of the Summon feature, where the Model 3 will just follow the RV at (say) 2 car lengths distance, mimicking any turn signals, flashers, brake lights, etc.
> 
> ...


I Like it! Or even better, have the car meet you at the RV park and set itself up with a charge before you get there. "Toad meet me at" and give gps and site#


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## UncleMoose (Sep 28, 2016)

garsh said:


> Yes, plus you miss out on the extra on-the-go recharging that you get by mimicking trailer brakes using regenerative braking.


Well, if the Tesla's autonomously following the RV, you should still get the same amount of regenerative braking as you would driving it manually.


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## garsh (Apr 4, 2016)

UncleMoose said:


> Well, if the Tesla's autonomously following the RV, you should still get the same amount of regenerative braking as you would driving it manually.


I was imagining the Model 3 helping to slow down the RV in addition to itself. Extra charging.


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## Randy (Aug 1, 2016)

Here's a weird thought, If a model 3 is autonomously following an RV, would the decrease in draft on the RV (because of a closely following vehicle) lead to a fuel savings in the larger vehicle? I'm not a Nascar guy but I am pretty sure that two cars following each other very closely can go faster than either car can on its own. I would take it that the wind resistance decrease is the reason for that. 
Randy


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## AEDennis (Apr 10, 2016)

Randy said:


> Here's a weird thought, If a model 3 is autonomously following an RV, would the decrease in draft on the RV (because of a closely following vehicle) lead to a fuel savings in the larger vehicle? I'm not a Nascar guy but I am pretty sure that two cars following each other very closely can go faster than either car can on its own. I would take it that the wind resistance decrease is the reason for that.
> Randy


I would hate to have the autonomously following Toad Model 3 be so close to the lead vehicle as to garner the savings you are hoping to achieve. As good as the tech is, I still think a safe distance is several car lengths from the lead vehicle.


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## Randy (Aug 1, 2016)

AEDennis ;
I get you , comparatively tho a Toad when physically connected is usually extremely close . . Maybe an over the air electronic link between RV and toad to insure toad knows the millisecond RV applies the breaks. I would hate to ding up that front end.The only thing that would really bother me would be the damage from road debris marking up my new beautiful m3. I know they make big screens for such toad vehicals but it would still bother me
Randy


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## AEDennis (Apr 10, 2016)

Randy said:


> AEDennis ;
> I get you , comparatively tho a Toad when physically connected is usually extremely close . . Maybe an over the air electronic link between RV and toad to insure toad knows the millisecond RV applies the breaks. I would hate to ding up that front end.The only thing that would really bother me would be the damage from road debris marking up my new beautiful m3. I know they make big screens for such toad vehicals but it would still bother me
> Randy


Vehicle to Vehicle communications is one of the things that folks who develop these things are considering and would be one way to ensure that an autonomously driving vehicle sees traffic "even better" than it does with its own eyes/cameras/radar/LIDAR/etc...

I just figure to send the car on its way and meet you where you're going. If your RV is ICE and the 3 needs to make its charges along the way, just tell it where to go and when it needs to be there to meet you.


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## chopr147 (May 23, 2016)

Drafting the RV will keep the bugs down. One thing I have learned with the Model S is that front end is like one big fly swatter that never misses. I am constantly cleaning bugs off the "grill"


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## Bobby Garrity (Jan 22, 2017)

garsh said:


> When the RV brakes, have the toad perform regenerative braking. Might as well charge the battery while also helping the entire rig to slow down.


That's a fantastic idea! I love it!


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## EMP40 (Jun 13, 2017)

It would be great to have a hybrid Class A motorhome and the Model 3 in a symbiotic relationship going down the road together where either could use or regen the other's batteries. Alas, if we become a full time RV couple soon we may have to give up on the M3 as campgrounds do not have room for motorhome, trailer, and car :-(


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## 3V Pilot (Sep 15, 2017)

Okay, I love this idea but how about......

A fully autonomous Tesla Semi following the Model 3 (which is a more comfortable to drive) and then the Semi can haul the RV!!


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## Brett (Aug 1, 2017)

How about just a Tesla RV, I think that would be awesome. Autopilot for the long stretches of road, charge overnight using the campgrounds 220v outlet, no engine noise, no generator (batteries will be big enough). Even stops at superchargers would be painless since you could kick back on the couch next to your fully stocked kitchen.


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## garsh (Apr 4, 2016)

Brett said:


> How about just a Tesla RV, I think that would be awesome. Autopilot for the long stretches of road, charge overnight using the campgrounds 220v outlet, no engine noise, no generator (batteries will be big enough). Even stops at superchargers would be painless since you could kick back on the couch next to your fully stocked kitchen.


I can easily see a Tesla Semi being converted into an RV by some third party.


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## 3V Pilot (Sep 15, 2017)

A fully autonomous Tesla RV would be perfect but since this thread is about "toad" cars I'll just keep dreaming of the day when Tesla designs an RV like the one below, complete with the next gen roadster underneath. Oh, and while there at it the roadsters batteries should be able to be charged or used to supplement the RV!


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## Rich M (Jul 28, 2017)

As far as towing, it would depend on how the 3's gearbox is cooled. Putting it in neutral doesn't disconnect anything, it just stops supplying or receiving current from the electric motor. While it's being towed the motor (and the entire gear reduction box and bearings) are still screaming along at highway speeds.
I thought I read somewhere that the motor/gearbox was part of the active battery cooling loop, and it was used to get some heat into the battery on cold days. Not sure if the inverse is true, but if that's the case I wouldn't tow far without somehow getting the coolant pump running.


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## 3V Pilot (Sep 15, 2017)

I could be wrong but I'd be surprised if they needed to run coolant to it. I believe the gear lube is all they need which would serve to lubricate and cool. It's just a single stage reduction gear, pretty simple and a regular old manual gearbox runs just fine with only the lube to cool it.


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## JWardell (May 9, 2016)

Rich M said:


> As far as towing, it would depend on how the 3's gearbox is cooled. Putting it in neutral doesn't disconnect anything, it just stops supplying or receiving current from the electric motor. While it's being towed the motor (and the entire gear reduction box and bearings) are still screaming along at highway speeds.
> I thought I read somewhere that the motor/gearbox was part of the active battery cooling loop, and it was used to get some heat into the battery on cold days. Not sure if the inverse is true, but if that's the case I wouldn't tow far without somehow getting the coolant pump running.


Are you sure it doesn't mechanically disconnect from the gearbox? Simple test I guess to jack it up and see how easily the wheels spin by hand.


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## 3V Pilot (Sep 15, 2017)

JWardell said:


> Are you sure it doesn't mechanically disconnect from the gearbox? Simple test I guess to jack it up and see how easily the wheels spin by hand.


Its a direct drive, no clutch needed, so I'm pretty sure it has no way to disconnect.....


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## Frank99 (Aug 3, 2017)

Remember that the supplier that Tesla canned back in January makes "axle driven lubrication pumps" - which may not actually be what they were going to supply to Tesla - which sounds like something that would be good in this scenario.
The nice thing about direct-drive is that any lubrication pump driven by the motor will also be driven when the car is getting towed. This was a problem with some ICE transmissions when being towed - the lubrication pump was driven by the engine side of the transmission, which didn't turn if the transmission was in neutral. 
Gearbox lube cooling would seem to be the only thing that might impact towing - and I don't know of any manual transmissions that require cooling, so the Tesla gearbox shouldn't require it either. But, I'm not willing to be the guinea pig on this one.


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## JWardell (May 9, 2016)

Mike Land said:


> Its a direct drive, no clutch needed, so I'm pretty sure it has no way to disconnect.....


It's not direct drive, there are reduction gears between the motor and the axle. ["Single speed" is a better term.] There's no reason why a gear can't be disengaged to enable true neutral if Tesla thought that would be smart to do.


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## 3V Pilot (Sep 15, 2017)

JWardell said:


> It's not direct drive, there are reduction gears between the motor and the axle. ["Single speed" is a better term.] There's no reason why a gear can't be disengaged to enable true neutral if Tesla thought that would be smart to do.


Okay, I guessed I used the wrong term there, I know it's a reduction gear between the motor and output shaft. My point being that there is no clutch needed because there is only one gear, no need to change, no need to disconnect or have a clutch. If you lifted the car and turned the tire you would not find the typical resistance of a ICE car because you will be turning the single gear and electric motor. Little to no resistance and really no reason for Tesla to add complexity or weight by adding any disconnect. I would assume that towing on all four would provide the same splash lubrication and cooling the single gear gets while being driven without the added heat of having to push the car along. I'm not an expert........and hey......I didn't even stay at a Holiday Inn express last night, LOL. Just my thoughts.......


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## Nazar (Nov 20, 2017)

love the ideas - especially the one about converting the truck and then having it follow the car automousaly.

not knowing too much about the tech of these cars i will draw from the knowledge i have from ICE cars (i have a cvt 4WD ) - if i need to get it towed it must be on a flatbed so none of the tires go around.. every youtube i have seen about breakdowns/loss of energy, has been with a flatbed truck, and considering the wheels can't be disconnected from the motor, is it even possible to tow a tesla in this way?


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## 3V Pilot (Sep 15, 2017)

Nazar said:


> love the ideas - especially the one about converting the truck and then having it follow the car automousaly.
> 
> not knowing too much about the tech of these cars i will draw from the knowledge i have from ICE cars (i have a cvt 4WD ) - if i need to get it towed it must be on a flatbed so none of the tires go around.. every youtube i have seen about breakdowns/loss of energy, has been with a flatbed truck, and considering the wheels can't be disconnected from the motor, is it even possible to tow a tesla in this way?


I noticed in Trev's video the "towing mode" screen specifically says that the Model 3 cannot be towed. Here is a screenshot:


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## Nazar (Nov 20, 2017)

Mike Land said:


> I noticed in Trev's video the "towing mode" screen specifically says that the Model 3 cannot be towed. Here is a screenshot:


thanks for the clarity,makes me wonder if this Toad "could" even be possible? maybe a better solution is follow mode like the truck uses. (years away)


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## garsh (Apr 4, 2016)

Nazar said:


> if i need to get it towed it must be on a flatbed so none of the tires go around..


Generally, this is because there is a pump to make sure that the transmission is properly lubricated when the car is running. If the engine is off, then this pump isn't running, and the transmission isn't being properly lubricated and can therefore be damaged.

Some vehicles can be somewhat easily converted to allow 4-wheel-down towing. My parents use a Honda CR-V converted for this purpose.


> ...considering the wheels can't be disconnected from the motor, is it even possible to tow a tesla in this way?


It's an academic question, because Tesla doesn't allow towing the Model 3 (thanks for the informative screenshot, @Mike Land). But, it shouldn't be an issue, as long as the reduction gearing is properly lubricated. Furthermore, if regenerative braking is used while being towed, then you would also need to run all of the motor coolant pumps as well, so that they don't overheat.


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## Guest (Nov 24, 2017)

Towing EV when drivetrain is active (aka D is engaged*) is *safe for drivetrain *to tow.
Towing EV when HV battery is disengaged (D does not engage) is *not safe* at those speeds.
When motor is turning at thousands RPM's it induces current. As there is nothing that manages that (no load)
voltage will spike and might *burn power electronics* that is permanently attached to motor windings.
At low speeds (up to 20-30km/h) it should be fine, depends on motor design, reduction gear.... At very low speed (walking) it is *definitely *safe. I've towed Leaf at 30km/h when drivetrain was dead.
At high speed (above 70km/h) it is *definitely *not safe for PM motor to turn. 
Some say that it might generate heat and coolant pump is not running. I don't think that is the real problem.
*Another danger *of towing EV when it's dead is due to main brake system difference. On ICE vehicles it is almost always assisted by vacuum and always has direct link between pedal and brake pads. It takes a lot of force but it works even if vehicle is absolutely dead. EV's often do not have any link between pedal and brake pads (for example, Nissan Leaf). It is possible, that Model 3 does not have direct link between brake pedal and brake system and might also not have buffering device (for example, brake vacuum buffer container or electrical capacitor buffer bank - Nissan Leaf uses that one). In this case there is no way towed vehicle can be slowed down if 12V system fails (and if will eventually). Parking/Emergency brake will also fail as that also operates on 12V (which has just failed, remember).
If somebody is interested in more drivetrain knowledge, good place to start is here:
https://www.youtube.com/user/WeberAuto

*It's possible to have N engaged when drivetrain is active. It's software N, not really neutral as in "electrically disengaged". 
Another way to know is the drivetrain engaged or not is to observe HVAC, if AC and/or heat doesn't work, drivetrain is disengaged.

Rope towing is getting less and less useful these days and redesigning a system JUST for that might be too expensive.
Those who know that they will not get to ANY PLUG should stop driving and, if they are sure how to drive a vehicle that is being towed, tow Model 3 when drivetrain is still active. LOW regen mode is recommended if vehicle that tows has limited performance.
For vehicle, it is not actually towing. It is driving downhill. Long drive downhill.

Because ALL THIS is complicated (and mortals always find a way to screw things up), Tesla, by default, does not allow rope towing.


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## Kizzy (Jul 25, 2016)

arnis said:


> […]It is possible, that Model 3 does not have direct link between brake pedal and brake system and might also not have buffering device (for example, brake vacuum buffer container or electrical capacitor buffer bank - Nissan Leaf uses that one). In this case there is no way towed vehicle can be slowed down if 12V system fails (and if will eventually). […]


Page 59 of the owners's manual mentions that the brake pedal may move slightly during deceleration while the vehicle is under control of traffic-aware cruise control. Is that a hint for its brake setup?

Edit to add: Page 76 mentions abrupt downward movement of the brake pedal during an automatic emergency braking maneuver.


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## Guest (Nov 24, 2017)

It does hint , but not state anything specific, like will it actuate brake caliper pistons when unpowered.
It's even possible that pedal is actuated by motor/servo for simplicity.


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