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Class 3 Towing Capability

Class 3 Towing Capability

Thanks to @EVino for posting the video of Tesla’s VP of Regulatory Affairs, Jim Chen:

http://tagtvonline.com/index.php?option=com_hwdvideoshare&task=viewvideo...

@TeslaTap.com found a nugget at 00:09:40.

This vehicle have class 3 Towing Capability. That means over 5,000 pounds--actually close to 10,000 pounds towing capability.

A chart from:

http://www.reese-hitches.com/learning_center/general-towing-classes

Class III

Class III hitches are weight carrying (WC) and also are weight distributing (WD) depending on the vehicle and hitch specifications.

Not all Class III hitches are rated to be both. See the specific hitch for that information.

Class III hitches used as weight carrying are rated up to 6000 lbs. gross trailer weight (GTW) with a maximum trailer tongue weight (TW) of 600 lbs.

Class III hitches used for weight distributing are rated up to 10,000 lbs. gross trailer weight (GTW) with a maximum trailer tongue weight (TW) of 1000 lbs.

A Class III hitch usually has a 2" square receiver opening.

A higher class drawbar does not increase the towing capacity of the hitch. To use this class of hitch for weight distribution requires a weight distribution system.

Class III hitches attach to the vehicle frame only.

--
So what can Model X actually tow?

Red Sage ca us | 25 maggio 2015

That puts it right in the range of my prediction from last year: 6,000 to 7,500 lbs towing.

Thanks!

georgehawley.fl.us | 26 maggio 2015

@Tâm: most excellent intelligence gathering and analysis! If true, the towing capacity of the MX will be quite impressive, although the tax on range will be equally impressive I fear. Go far or tow not so far. Take your pick. I'm guessing that 150 miles with a full load will be a stretch with an 85 kWh pack.

Ever so slowly the picture becomes clearer.

vperl | 26 maggio 2015

Pulling a load up the hill from like say Medford,OR to Mt.Shasta ought to be interesting.

Laughable.

Red Sage ca us | 26 maggio 2015

No. The actual act of towing would certainly induce the Tesla Grin due yo the sheer ease of the action... It would be the relatively sudden decrease in available energy reserves upon reaching the destination that would illicit dejected frowns. Not laughable in any way.

georgehawley.fl.us | 26 maggio 2015

Easy beezy. Drive part way up. Unhitch the trailer. Recharge by rolling back down. Charge some more at the bottom. Drive back up. Pick up the trailer and repeat. Electric magic. ;-))

vperl | 26 maggio 2015

Yep, towing 3 tons of trailer up the Siskiyou mountains ought to be a breeze.

johnse | 26 maggio 2015

Just thinking about the actual work imparted on the trailer to bring it to Siskiyou pass elevation 1314m (assuming from sea level)...
mass = 2721 kg
g = 9.8 m/s^2
d = 1314 m

Work = m * g * d = 35.04MJ = 9733 Wh or 9.733 kWh

So, ignoring the aerodynamic drag, this would imply that about 11% of an 85kWh battery's charge would be spent hauling the extra mass up the mountain.

This suggests that towing isn't actually as detrimental range as one might have thought. Drag might be, but you can mitigate that by driving more slowly or having more streamlined trailers.

Please point out if my 40-years dormant physics has flaws in it :)

jjs | 26 maggio 2015

@johnse Although the 85kWH battery has at least the capacity to store 85kWH of power when new, not all of it is usable. Some is saved as a buffer to protect the battery from damage. It has been estimated at about 10%. So assume usable battery power of 76.5 kWH. So if your calculations regarding the work required is correct it would be more like 13%. Still not too bad. If you consider a round trip then you get to recover some of that on the trip back down.

georgehawley.fl.us | 26 maggio 2015

@johnse: let's see. There is also the work getting the MX up the mountain, another 2.3 kg. there is also the rolling friction to overcome, about 300 wh/mile for the trailer plus the MX and then there's the drag depending on speed. 150 miles gobbles up more than 45 kWh on top of the 20 kWh of work elevating the car plus load. That's 65 kWh not counting drag and things like climate control. That's why 150 miles is a stretch.

But it is still pretty good.

vperl | 26 maggio 2015

Yep, a real breeze.

Now try Lincoln, Nebraska to Rawlings,Wy on I-80 West

A zip also.

vperl | 26 maggio 2015

Yep, a real breeze.

Now try Lincoln, Nebraska to Rawlings,Wy on I-80 West

A zip also. It is only towing Three tons. A breeze.

jhrasmussen | 27 maggio 2015

Extra KWH to elevate any trailer is understood. But how many % of those extra KWH will the MX regenerate/recover when sliding down ?

jamesmd | 27 maggio 2015

That's awesome. I use a class 3 hitch on my BMW X3 3.5 to pull my wakeboard boat which is close to 3000lbs. I can get it up to the cottage (although always have trouble taking the boat out since we have a beach and the wheels often spin in the sand) without any trouble. This means I can keep my Panamera and sell the X3 instead of selling my Panamera and keeping the X3 :) (we need something to tow the boat)....although I'm not sure my wife would approve of selling her car

David Trushin | 28 maggio 2015

Towing 6000 pounds in a 5000 pound vehicle means probably a max of 45% of the unloaded range. Plus there will be an additional subtraction for wind and rolling resistance. So maybe 35%to 40% of the unloaded range.

PMadFlyer | 28 maggio 2015

It doesn't work like that. On the highway, aerodynamic drag plays a much greater role than mass, except for elevation changes.

Off the top of my head, I'd expect maybe 75% of normal range with your 6000 pound hypothetical trailer.

TytanX | 8 giugno 2015

I can't wait to pull into Supercharger station towing my camper. I'll probably have to park across all 6 (or 8) stalls just to get close enough to the supercharger but at least I'll get to charge.

Red Sage ca us | 8 giugno 2015

Newer Supercharger stations tend to include at least one sidesaddle, pull-through space, to accommodate towing. Hopefully that will be the standard arrangement, should Tesla Motors ever develop Tesla Depot/Waypoint locations to service EVs. I would like that.

vperl | 8 giugno 2015

A real Tesla owner, would unhook trailer charge vehicle at hook up and be gone. Hope you do not do as you mentioned. Bet some might want to talk to you.

grega | 8 giugno 2015

It has to be a huge hit on range.

Once rolling along the highway, it's drag will be significantly higher than the Model X. I wouldn't be surprised if it was more than double.

Accelerating it'll require double the energy if it's double the weight. But decelerating will probably activate the trailer brakes, which don't do any regeneration.

So I think it might be ideal for someone taking a heavy boat or any short haul - with lots of torque etc. But long trips I'd be concerned about - unless a camper van has multiple Tesla Wall battery packs, charged by roof solar cells and regenerative braking, able to directly charge the Model X while driving.

Red Sage ca us | 24 giugno 2015

rbi: This is good news! I had estimated the tow rating for Model X at over 6,000 lbs last year. That was based on an offhand comment by a Tesla Motors representative made in 2013. If it has a range over 200 miles while towing 8,000 lbs or more, the Model X will fulfill a lot of needs, and dumbfound many EV Naysayers.

Brian H | 25 giugno 2015

Range: >200 mi
Towing: ~10k lbs.

Pick one.

the bonnie | 25 giugno 2015

@TytanX

"I can't wait to pull into Supercharger station towing my camper. I'll probably have to park across all 6 (or 8) stalls just to get close enough to the supercharger but at least I'll get to charge."

Seriously? You can't take just a minute to drop your camper and rehook it up? It doesn't take that long (I have a camper and that's what I plan to do). Here, let's walk through the steps:

1) Block wheels
2) Unplug the wiring
3) Disengage the safety loop
4) Crank it up to disconnect

That really isn't very hard. I have faith in you.

grant10k | 25 giugno 2015

It also really isn't very hard to walk around the car and manually lock all 4 doors and the trunk, but I'm still going to press the button.

And no, TytanX isn't being serious.

matt | 1 luglio 2015

I tow an Ariel Atom in an enclosed small trailer behind a 2014 Honda Odyssey to the track. I will sell the Odyssey as soon as our MX reserve number (~10K) comes up.

Since trailers with two axles require a brake controller (at least in CA) to be installed in a tow car, would it be unrealistic to think Tesla would integrate the trailer brake controller into the future towing package?

TytanX | 1 luglio 2015

Yes of course I was kidding. Relax.
But It will happen. It just won't be me.

Tâm | 3 agosto 2015

As you can see from the picture below, the Model X prototype is hauling what appeared to be predetermined weight/load tied down to a trailer:

http://gas2.org/2015/07/31/tesla-model-x-spotted-hauling-a-trailer/

Does it mean I can haul more than a lightweight teardrop trailer?

Does it mean I can haul a monstrously big Airstream?

ian t.wa.us | 3 agosto 2015

Likely but at what cost to the range?

jjs | 3 agosto 2015

Depends upon if you are going uphill or down. ;)

eric.zucker | 4 agosto 2015

Here tailers above a certain weight (750 kg or 1650lbs) must have brakes for safety's sake.
This means one will not recover all the energy when going downhill...

Might it be possible to adjust the trailer's brake to kick in only if the deceleration is greater than a certain limit without compromising security?

vandacca | 4 agosto 2015

Maybe the trailer brake will only kick-in when the driver actually depresses the brake? Otherwise, only regen will occur when the user takes his foot off the accelerator.

eric.zucker | 4 agosto 2015

The trailer brake is activated whenever the car slows down, the trailer's inertia compresses a piston between the car and trailer and this applies the brakes. Whether it's regenerative braking or not is irrelevant..

jjs | 4 agosto 2015

Not all trailer brakes work that way.
Also, even if there is no regen you still get LOTS of mileage going down hill since you are expending no energy to do so.

aaquino22 | 4 agosto 2015

Correct me if I'm wrong. Regenerative braking is taking your foot off the pedal not hitting the brakes. So as long as you don't hit the brakes, shouldn't you get the full benefit of regenerative breaking with a full trailer weight?

aaquino22 | 4 agosto 2015

How cool would it be to have an extended range "Powerwall 10kWh" option for camper trailers. Then, regenerative braking can be built into the axles initiated by "inertia."

Tâm | 3 ottobre 2015

Now that the Model X webpage has more details, its towing capacity is 5,000 pounds.

Some reservation holders are disappointed and still expect the 10,000 pound towing capability as stated in the video.

Red Sage ca us | 3 ottobre 2015

My guess is that a weight distribution hitch is needed to achieve a higher tow rating. If it is possible, look for it to come from Torklift Central. However, the 5,000 lbs limit is likely to allow a range necessary to achieve at least a Real World 150 mile distance between Superchargers.

danej | 3 ottobre 2015

I really wish it'd haul 6,000lbs GVWR trailer, with a load equalizing hitch in the receiver. This would let us pull an Airstream big enough to sleep six people! It's very close; the empty weight ("unit base weight) of the smallest unit that sleeps six is 4761lbs, but the GVWR is 6,000. The difference is the "net carrying capacity", a bit over 1200lbs. This is water and waste tanks, dishes and clothes, etc.

http://www.airstream.com/travel-trailers/international/signature/

I don't think it'll be legal nor advisable to overload your towing capacity, so I guess the a couple of the kids get to sleep in a tent! Hope there are no bears! ;)

-Dane

Tâm | 4 ottobre 2015

Jim Chen is a lawyer, not an engineer, so you have to watch his words very carefully:

"This vehicle have class 3 Towing Capability. That means over 5,000 pounds--actually close to 10,000 pounds towing capability."

He said the car is classified as class 3 Towing Capability.

I think we all thought that "10,000 pounds" were meant for the Model X.

However, his subsequent words could be interpreted that he was explaining what ANY car within the class 3 Towing Capability could do: from 5,000 and up to 10,000 pounds.

He could be defining the range of numbers for class 3 Towing Capability, not for the Model X itself.

Red Sage ca us | 4 ottobre 2015

Tâm: That's what I've felt all along... I was sort of waiting for someone else to say it though. I'm not often believed when I say such things.

;-)

Tâm | 8 ottobre 2015

From tmc forum: Please be advised that 5,000 pounds is meant for 20" wheels.

If you plan on 22" then it's 3,500 pounds.

georgehawley.fl.us | 8 ottobre 2015

Word "on the street" is that the X will actually tow up to 7,000 lbs, probably with 20" wheels but 5,000 lbs coincides with the highest rating it can get.

Steinwand | 8 ottobre 2015

I heard, from what would hopefully be a reliable source at a service center, that WORST case scenario being max load of 5000lbs and 8% hill grade (which is about as bad as it gets) would give you 32 miles on a full charge. Not sure at what speed that is and going back down that same hill would give you a lot back.

gordonbremer | 9 ottobre 2015

Perhaps Tesla will comment on the potential value of Ludicrous Mode with regard to towing. I understand that Ludicrous hardware will permit 25% higher battery current for a short duration. That 25% power increase may be beneficial at times (not just on all-out acceleration).

Related, will the hardware provide increased reliability as well.

vandacca | 9 ottobre 2015

Sounds like someone is trying to justify the Ludicrous option. ;-)

johnse | 11 ottobre 2015

@Steinwand WORST case scenario being max load of 5000lbs and 8% hill grade (which is about as bad as it gets) would give you 32 miles on a full charge.

I would say that's fairly plausible, but you have to ask whether it's really a valid case.

An 8% grade means the rise in elevation is 8% of the run. If you go 32 miles, that means you will climb 13500 feet. Most of the mountain passes are significantly lower than that.

Now, if you did have an 8% grade climbing a 13500 foot change in elevation, there are two components to the use of energy coming from the battery pack:
1) normal losses due to friction and drag
2) potential energy to lift 11000 pounds (6000 loaded vehicle and 5000 pound trailer) 13500 feet.

#2 alone, with no friction or drag will use 55.7kWh of energy (200.4MJ) That leaves you with less than 35kWh for friction and drag, which would imply about 1kWh/mile when traveling on a flat road. That seems just a tiny high to me, but will certainly depend on what you're towing.

But, if you're going a more reasonable 1/4 of that vertical, you're looking at 13-14kWh given up to elevation gain, leaving you about 70kWh of usable energy for making it between superchargers.

You're going to need to do test runs with anything you're towing to see what your actual performance is.

Ross1 | 11 ottobre 2015

I looked at the Airstream link: fantastic piece of kit!

I suspect with Ludicrous mode you might need to tie stuff down, and don't be surprised if you can't do 0-60 in 3.4 secs with the Airstream on.

Iowa92x | 11 ottobre 2015

Battery/motor cooling system in the X won't keep up with towing a load up a mountain pass, good luck pulling that $60k, 5,000 lb Airstream up I70 at 65mph.

Tâm | 23 ottobre 2015

Remember good old time at the Model X Launch Event?

The information said "Limited Model S charging will be available."

Well, look real hard again!

20 Supercharger bays right there:

It's pull through design which should accommodate so don't have to unhitch your trailers!

Red Sage ca us | 25 ottobre 2015

It doesn'appear to be 'pull through', but 'pull in'... There are curbs and a burm on one side, if'n ye look closer.

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