Lots of towing speculation but...

[Michael.Cugno]

There's been quite a bit of towing speculation on the CT owners club site and others. Hopefully, Tesla will come out with real numbers sooner than later. Down here in Florida, it's pretty much flat. I've got an order in for the Trip-motor. I'll be charging mostly from home. All I need to know if what % of charge do I need to tow a boat/trailer/gear of 4,000lbs or less, 200 miles? My fishing grounds cover the keys, Everglades, Big Cypress. The national parks down here (Biscayne and Everglades) will have charging stations. I don't want to have to use them. I have kayaks, paddle boards, etc...and with the charging and range w/o towing, an 80% should be a no-brainer for range. Anyone else in this situation? Tesla! Can't wait for the numbers.

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[ajdelange]

Judging from the number of your messages you are new here (Welcome!). This is, of course, a subject of great interest which has been discussed at GREAT length here. The simple fact of the matter is that Tesla does not, and will not, have the numbers you seek because the answer depends solely on how much "power" the trailer draws relative to how much the CT uses when not towing and that power consumption depends on the trailer, how you load it and how, where and when you tow it. At best, then, the trailer would have its own EPA consumption rating.

If pulling the trailer on level ground at 65 mph requires 450 Wh/mi and the truck, with no trailer, consume 450 Wh/mi on level ground when not drawing a trailer then it is evident that the pair will requiret 450 + 450 Wh/mi = 900 Wh/mi. As this is double that of the CT alone it is apparent that the range with the trailer will be about half what it is without.

The calculation is somewhat invalidated by the fact that the efficiencies you obtain from regeneration in the truck will not be available with the trailer as the truck will not be able to absorb the regen load from the trailer, this will have to be absorbed by the trailers friction brakes and thus the battery energy invested in the kinetic and potential energies of the payload and trailer will no be recovered.

The short answer is that no one will know what the effect on range of a particular trailer load is until someone pulls that trailer load. Musk has promised great things in the CT software in aid of towing. Something as simple as a load cell in the hitch would allow the truck to calculate the trailers energy utilization per mile. This would at least allow the CT onboard range estimation software to give better estimates than it would otherwise.

Elaborate calculations and simulations have been performed and when all is said and done the answer for nominal conditions seems to come out at 50% range loss. A lot of guys, while recognizing that range reduction to 20 to 30% is entirely feasible, use 50% as a starting number.

So sorry, but until you have that critical trailer parameter, you can't tell much about what will happen when you tow.

But I can tell you how much to charge at home. !00% or as close to it as you are comfortable with. Your 500 mile CT has a practical working range of 400 miles and, using the rule of thumb above, with a trailer that's likely to be cut down to 200 or less. You didn't say whether the 200 miles was round trip or one way. If one way you will definitely have to charge on the road. The only reason to avoid super chargers if towing is that not many stalls are set up to allow pull through. You may have to decouple, charge, and then couple up again.

 

[Michael.Cugno]

Judging from the number of your messages you are new here (Welcome!). This is, of course, a subject of great interest which has been discussed at GREAT length here. The simple fact of the matter is that Tesla does not, and will not, have the numbers you seek because the answer depends solely on how much "power" the trailer draws relative to how much the CT uses when not towing and that power consumption depends on the trailer, how you load it and how, where and when you tow it. At best, then, the trailer would have its own EPA consumption rating.

If pulling the trailer on level ground at 65 mph requires 450 Wh/mi and the truck, with no trailer, consume 450 Wh/mi on level ground when not drawing a trailer then it is evident that the pair will requiret 450 + 450 Wh/mi = 900 Wh/mi. As this is double that of the CT alone it is apparent that the range with the trailer will be about half what it is without.

The calculation is somewhat invalidated by the fact that the efficiencies you obtain from regeneration in the truck will not be available with the trailer as the truck will not be able to absorb the regen load from the trailer, this will have to be absorbed by the trailers friction brakes and thus the battery energy invested in the kinetic and potential energies of the payload and trailer will no be recovered.

The short answer is that no one will know what the effect on range of a particular trailer load is until someone pulls that trailer load. Musk has promised great things in the CT software in aid of towing. Something as simple as a load cell in the hitch would allow the truck to calculate the trailers energy utilization per mile. This would at least allow the CT onboard range estimation software to give better estimates than it would otherwise.

Elaborate calculations and simulations have been performed and when all is said and done the answer for nominal conditions seems to come out at 50% range loss. A lot of guys, while recognizing that range reduction to 20 to 30% is entirely feasible, use 50% as a starting number.

So sorry, but until you have that critical trailer parameter, you can't tell much about what will happen when you tow.

But I can tell you how much to charge at home. !00% or as close to it as you are comfortable with. Your 500 mile CT has a practical working range of 400 miles and, using the rule of thumb above, with a trailer that's likely to be cut down to 200 or less. You didn't say whether the 200 miles was round trip or one way. If one way you will definitely have to charge on the road. The only reason to avoid super chargers if towing is that not many stalls are set up to allow pull through. You may have to decouple, charge, and then couple up again.

Thanks for the info.
My typical trip is 150 miles (roundtrip) total. If I can get 200 miles on a charge, I’m OK with that. Plus, the solar panel may add 15 miles as I can leave the CT in full sun for 8-10 hours. 200 miles, one way, with a charge up later is doable as well.

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