Model X tow capacity is too low for me

[BerTX]

I occasionally tow a 10,000lb boat with a Ford Excursion and I would no more try to tow it with my new Model X than I would to fly the X off a bridge. Based on my personal experience, I would not tow a trailer heavier than the car I'm driving...too scary in an emergency. I would also guess that you would be lucky to get 100 miles with even a 5000lb load.

I always get confused when someone says they would never tow something heavier than the vehicle they are towing with. Your Ford Excursion weighs 6700 pounds and you are towing a 10,000 pound load? The Excursion only weighs 600 pounds more than the MX.

I agree the MX has no business trying to tow large loads very far, but not large in weight -- it's the volume that will be the problem. The loss in range on the highway will be from drag as well as weight. That's where people will get into issues, thinking their 4500 pound travel trailer is within the capability of the MX, which it is, but due to drag increases they will have to drive 45 MPH to get between Superchargers.

With an ICE, it's "oh crap I got bad gas mileage". With the MX, it will be "hello, AAA?"

 

[BriansTesla]

I always get confused when someone says they would never tow something heavier than the vehicle they are towing with. Your Ford Excursion weighs 6700 pounds and you are towing a 10,000 pound load? The Excursion only weighs 600 pounds more than the MX.

I agree the MX has no business trying to tow large loads very far, but not large in weight -- it's the volume that will be the problem. The loss in range on the highway will be from drag as well as weight. That's where people will get into issues, thinking their 4500 pound travel trailer is within the capability of the MX, which it is, but due to drag increases they will have to drive 45 MPH to get between Superchargers.

With an ICE, it's "oh crap I got bad gas mileage". With the MX, it will be "hello, AAA?"

The 2001 7.3L curb weight is 7697 and the Sea Dory Tomcat is probably somewhat less than 9500 but is is scary if you have to make any sudden lane changes or stops. The mileage goes from about 15 to 10. I think the X would see a lot of 1000+ Wh/mi.

 

[robby]

It may well be that early testing showed the vehicle to be capable of towing a 10,000 load, but that does not necessarily grant it a 10,000 load rating.

The brakes need to be able to handle it, the transmission often need to have additional coolers, the suspension needs to be able to carry the weight (with acceptable comfort and control). It may be that the without a load transferring hitch that the final rating needed to be adjusted.

Believe a 10,000 capability might be there, but not a 10,000 rating.

Believe that Tesla is doing the right thing here, by giving it a conservative rating right out of the box. Maybe later editions might have higher ratings.

On a more positive note, maybe in the near future we will see the Model S achieve a 3,500 lb rating that will allow towing small boats, jet skis, snowmobiles, moving trailers or camping trailers. They certainly have the low end torque, and might give us even more flexibility with our all electric vehicles.

Assuming they add towing to MS, why would it have a lower rating than MX?

 

[brkaus]

Assuming they add towing to MS, why would it have a lower rating than MX?

Larger vehicle adds more stability (well, taller also takes away). Larger tires can handle more load. Possibly larger brake rotors. Vehicle weight distribution. Frame design and how hitch can attach.

 

[robby]

Larger vehicle adds more stability (well, taller also takes away). Larger tires can handle more load. Possibly larger brake rotors. Vehicle weight distribution. Frame design and how hitch can attach.

Interesting, thanks. I figured since the frames would be similar so should the capacity. I didn't consider that the limitation may be braking or handling rather than structure. That is a good point.

 

[smac]

Interesting, thanks. I figured since the frames would be similar so should the capacity. I didn't consider that the limitation may be braking or handling rather than structure. That is a good point.

The MS really shouldn't struggle to tow the legal limit in the EU based on it's weight, wheel size, or brakes. The brakes are bigger than on a Merc ML, it weighs the same, etc. etc.

As BerTX says the problem for both the MS and MX as tow vehicles is the range. The MS had the lowest aero drag rating of any car, this wasn't by accident. Sticking a trailer on the back will seriously impact airflow, and have a really negative impact on range.

Tesla could get away without putting a towbar on the Model S, as it didn't need it in it's segment. The X HAS to be able to tow, or it simply wouldn't be an SUV. It wouldn't surprise me at all though if you got < 100 mile range towing anything more significant than a 500kg trailer Any trailer with brakes will make an even larger difference.

If people are seriously holding out for the X over an S because it has towing "capabilities", I can't help but think they are in for a disappointment unless it's for very local use.

 

[Yggdrasill]

The MS really shouldn't struggle to tow the legal limit in the EU based on it's weight, wheel size, or brakes. The brakes are bigger than on a Merc ML, it weighs the same, etc. etc.

As BerTX says the problem for both the MS and MX as tow vehicles is the range. The MS had the lowest aero drag rating of any car, this wasn't by accident. Sticking a trailer on the back will seriously impact airflow, and have a really negative impact on range.

Tesla could get away without putting a towbar on the Model S, as it didn't need it in it's segment. The X HAS to be able to tow, or it simply wouldn't be an SUV. It wouldn't surprise me at all though if you got < 100 mile range towing anything more significant than a 500kg trailer Any trailer with brakes will make an even larger difference.

If people are seriously holding out for the X over an S because it has towing "capabilities", I can't help but think they are in for a disappointment unless it's for very local use.

I think the range hit when towing a 2000 kg/4500 lb trailer will be somewhere in the area of 40%. So a 90D might get something like 150 miles of range.

There are several factors to consider:

- Little additional ancillary losses. (Lights, A/C, heating, pumps, screens, etc.)
- Not quite a doubling of tire resistance, which is mostly proportional to curb weight.
- Not quite a doubling of air resistance. (Luckily, the trailer is drafting behind the Model X.)
- Lower speed and almost certainly lowered acceleration in tow mode.
- Increased braking losses. (Fairly easily mitigated by hypermiling.)

Of course, if you're towing something very tall and boxy, with 2-3 axels and bad tires, where the brakes are sticking on, and you're driving in stop-and-go traffic, etc. You will be hard pressed to get more than 75 miles of range, but it should be fairly easy to get 150 miles in most normal circumstances.

I have for the past three years been waiting for AWD and tow hitch on a Tesla. I don't need to tow anything very far, nor anything very heavy, but having the tow hitch is the difference between having a single car and having two cars.

 

[Yggdrasill]

Thinking about it, I think you could probably get past 200 miles range towing 2000 kg. The trailer would have to be fairly good, not very tall and with an aerodynamic cover, low rolling resistance tires, and you would need to be towing something with sufficient density, like bricks, cinder blocks, etc. Also you would need to be carful with your energy consumption, keeping it at 50 mph or less and using hypermiling tecniques.

 

[Parax]

I don't think there is any error in Jim Chen's statement, lets break it down a little:
“This vehicle will have Class III towing capability. That means over 5,000 pounds,”
That's pretty clear. The vehicle is rated as Class III..
“actually close to 10,000 pounds of towing capability,”
This is pretty clear too. In testing the Vehicle came close to 10,000 pounds towing.


So what have we got?
A vehicle that came close to 10,000 pounds capacity in testing comes out of the factory as a Class III Towing Capability.

 

[jhs_7645]

I think the range hit when towing a 2000 kg/4500 lb trailer will be somewhere in the area of 40%. So a 90D might get something like 150 miles of range.

There are several factors to consider:

- Little additional ancillary losses. (Lights, A/C, heating, pumps, screens, etc.)
- Not quite a doubling of tire resistance, which is mostly proportional to curb weight.
- Not quite a doubling of air resistance. (Luckily, the trailer is drafting behind the Model X.)
- Lower speed and almost certainly lowered acceleration in tow mode.
- Increased braking losses. (Fairly easily mitigated by hypermiling.)

Of course, if you're towing something very tall and boxy, with 2-3 axels and bad tires, where the brakes are sticking on, and you're driving in stop-and-go traffic, etc. You will be hard pressed to get more than 75 miles of range, but it should be fairly easy to get 150 miles in most normal circumstances.

I have for the past three years been waiting for AWD and tow hitch on a Tesla. I don't need to tow anything very far, nor anything very heavy, but having the tow hitch is the difference between having a single car and having two cars.

Best estimate I've seen yet.

Off the top of my head I think we're looking at 40-50% loss as well, here's my (very basic) thinking.

Right now, I drive a Toyota Sequoia which gets 13 MPG, when we tow (8,000 lbs) we get 9 MPG. I see no reason why the MX would experience more loss than that. Now.. if Tesla could figure out a way to get regen breaking from the trailer.. *that* would be awesome.

 

[Cottonwood]

Right now, I drive a Toyota Sequoia which gets 13 MPG, when we tow (8,000 lbs) we get 9 MPG. I see no reason why the MX would experience more loss than that. Now.. if Tesla could figure out a way to get regen breaking from the trailer.. *that* would be awesome.

Because the aerodynamics of the MX are so much better than the Sequoia, there will be less of a draft for the trailer to follow in. On top of that when you start from such a good mileage point, the same (or worse) aero drag of the trailer will be much worse as a percentage loss to the towing vehicle. Let's do a hypothetical example in EV terms. Assume that the Sequoia needs 800 Wh/mi to drive at highway speeds, the MX needs 400 Wh/mi, and the Trailer needs 400 Wh/mi. The Sequoia plus trailer need 1200 Wh/mi for a 50% increase in energy needs and a 33% reduction in range. The MX plus trailer need 800 Wh/mi, a 100% increase in energy use and a 50% reduction in range. Remember, just putting a bike rack and bike on the back of an MS can produce losses of 20% or more. Remember that some trailers are very "draggy." The range loss for the MX with a "draggy" trailer could be much worse than my hypothetical.

The real advantage of electric trailer brakes is that the MX can modulate them for maximum regen gain while staying safe. In dry, good-traction conditions, the MX can only apply trailer brakes when the brake pedal of the MX is used, surge brakes might apply some friction braking under strong regen. On top of that, is more slippery conditions, the stability control could apply some trailer brakes under strong regen to keep MX and trailer safe.

 

[Yggdrasill]

I would be very careful with comparisons with fossil cars. You need to account for the variations in efficiency for the engine, and that's not something you can do on the back of an envelope.

Also, a bike rack really only matters at higher speeds, where air resistance is completely dominant, something that's mostly irrelevant when towing. (The maximum allowed speed here while towing is 50 mph, though I'm not sure what the regulation is elsewhere.)

 

[tga]

My boat trailer is similar. There is a brake cylinder in the trailer hitch. As the trailer pushes forward and exerts pressure towards the tow vehicle it applies the brake. I believe they are called surge brakes.

Surge brakes are common on boat trailers. I've never seen a boat trailer with electric brakes (do you want to dip them into sea water?)

But I've never seen a non-boat trailer with surge brakes (except the dual-axle Uhaul, so it can be pulled impromptu by a vehicle without a brake controller). Every boat, horse, and (non-Uhaul) cargo trailer I've seen has electric brakes. They offer a number of advantages (smoother, no surging if not configured correctly, emergency activation by the driver to stop sway).

Someone asked how the electric brakes are controlled. If the X trailer package doesn't include an integrated brake controller, you'd add a Tekonsha or the like. They use an accelerometer and a signal from the break light to indicate braking (breaking vs slow coasting) to control the brake output to the trailer. Should work fine with the X (although the trailer brakes won't regen).

Based on my personal experience, I would not tow a trailer heavier than the car I'm driving...too scary in an emergency.

My Chevy 2500 weighs around 6000 lbs. It is rated to pull 10k. The 3500/F-350 are around 13k-14k (>double the truck weight). In the extreme example, a tractor trailer cab weighs around 20k lbs, pulling a trailer weighing 3 times that or more (but now we're talking about fifth wheel hitches, road trains, etc, which is a whole new level of crazy).

Just curious. For those who wanted to tow 5,000-10,000 pounds what did you expect as far as range?

My boat trailers weigh ~1500 lbs and 5000 lbs. I only need ~25 miles of range for those.

The race car trailer is a more interesting thought experiment. I'm guessing the empty trailer is around 2000 lbs (never weighed). Car is 3k, plus another ~500 for a second set of tires, spare parts and tools, etc, so around 5500 lbs total. Replacing that with a lightweight aluminum open deck trailer could shave off another 1100-1200 lbs.

Looking at the various local tracks, the longest run I need between home, superchargers, and the track is ~100 miles, going from MA to Mont Tremblant, QC or Watkins Glen, NY. Probably not practical.

 

[smac]

I would be very careful with comparisons with fossil cars.

We are in agreement here

Until someone actually has one, tries to tow something close to it's rated limit, and shows the Wh/mi figure this is all speculation.

I'm with Cottonwood. The % efficiency of the X MAY be more impacted by towing than a brick of an SUV, on aero and regen grounds. But like calculating max efficiency under load an ICE goes through we simply won't know.

 

[jhs_7645]

Because the aerodynamics of the MX are so much better than the Sequoia, there will be less of a draft for the trailer to follow in. On top of that when you start from such a good mileage point, the same (or worse) aero drag of the trailer will be much worse as a percentage loss to the towing vehicle. Let's do a hypothetical example in EV terms. Assume that the Sequoia needs 800 Wh/mi to drive at highway speeds, the MX needs 400 Wh/mi, and the Trailer needs 400 Wh/mi. The Sequoia plus trailer need 1200 Wh/mi for a 50% increase in energy needs and a 33% reduction in range. The MX plus trailer need 800 Wh/mi, a 100% increase in energy use and a 50% reduction in range. Remember, just putting a bike rack and bike on the back of an MS can produce losses of 20% or more. Remember that some trailers are very "draggy." The range loss for the MX with a "draggy" trailer could be much worse than my hypothetical.

The real advantage of electric trailer brakes is that the MX can modulate them for maximum regen gain while staying safe. In dry, good-traction conditions, the MX can only apply trailer brakes when the brake pedal of the MX is used, surge brakes might apply some friction braking under strong regen. On top of that, is more slippery conditions, the stability control could apply some trailer brakes under strong regen to keep MX and trailer safe.

Excellent thoughts... Thank you for replying. I do think, however that you are overestimating the Wh/mi needed to pull a trailer, but overall, I think you're estimates are pretty realistic.

- - - Updated - - -

All that being said, I'm still hoping for a Model X that can tow a small two person Travel Trailer: (Alto Travel trailers by Safari Condo for example) and make it between superchargers. Cross country - free travel, and camping.. awesome dream.. let's hope Tesla made that a reality.

 

[Merrill]

In my opinion if you need to tow something over 5000 lbs, why would you tow it with an electric SUV? Buy a truck for that, especially if it is close to 10,000 lbs.

 

[Karma]

These are great points, and I think it should be added that the wheel base of the MX is too short to be towing 10k in weight, or a TT of greater length. You're a jack-knife accident just waiting to happen, and you'll be a danger to me, and everyone else on the road if you try it. Not sure that the torque of the MX motor will be able to get these things moving either...but I'll let the engineers chime in on this.

If you really need a tow vehicle for your TT, boat, airstream, etc., just get a diesel rig. No one will bash you. It's safer, and there is no question that it'll be able to meet your towing needs.

 

[JimVandegriff]

All that being said, I'm still hoping for a Model X that can tow a small two person Travel Trailer: (Alto Travel trailers by Safari Condo for example) and make it between superchargers. Cross country - free travel, and camping.. awesome dream.. let's hope Tesla made that a reality.

I'm with you jhs_7645. I've been researching single axle travel trailers, trying to keep total weight under 4000 lbs. We will be traveling to Portland in a couple of weeks for the RV show to see what is available. I really want to limit my use of fossil fuels, and I'm hoping the X can help me do that (and still travel where we want to go.)

 

[FlasherZ]

These are great points, and I think it should be added that the wheel base of the MX is too short to be towing 10k in weight, or a TT of greater length. You're a jack-knife accident just waiting to happen, and you'll be a danger to me, and everyone else on the road if you try it. Not sure that the torque of the MX motor will be able to get these things moving either...but I'll let the engineers chime in on this.

The peak torque of a Chevy 2500HD pickup is ~750 lb-ft, but you have to have the engine spinning at 2000+ RPM to get 80% of that (which wears on the transmission clutch). Contrast that with Tesla's motor, where all of its torque is available at 0 RPM. There's debate as to the actual torque specs -- Tesla said ~690 lb-ft, some independent dyno confirmations have put it at ~860 lb-ft, etc. There's plenty of torque to make 10k lbs. start to move.

I have a class B boat trailer and a vehicle trailer with a GVWR of 6k that I think the Model X should be able to tow without problems. I won't be attempting to attach a gooseneck or pull a bulldozer with it, though - for that I'll stick to my 3/4-ton pickup.

 

[hill]

I figure with a 5K towing capability, that'd allow you to trailer around an extra 90kWh traction pack. Between the extra drag & weight - I wonder what the range would be.
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