Cybertruck Towing Range

[ajdelange]

Because the last post was long and probably confusing to many (uses dreaded math) I took the formulas and used them to make the following picture based on several assumptions. Because of this the graph cannot be expected to produce accurate estimates of what range one will get with a particular trailer but rather give an idea of what the implications of increasing trailer weight and grade are when a trailer is towed.

To use the graph find the intersection of the grade and trailer weight. Now look at the curves to the left and right of this and note the numbers on them. Multiply the number on the closest curve by the range of your CT without a trailer. For example if you have the 500 miles Trimotor and the closest curve is labeled 0.6 your estimate is 0.6*500 = 300. You can refine the estimate by interpolating between the two closest curves. For example, if your intersection lies half way between the 0.5 and 0.6 curves the factor is 0.55.

Because this is an attempt to simplify I'll refrain from discussing the assumptions or the implications of changing them but will be happy to respond to any questions.

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[cybrtrk_maybe]

I like your graph. Easy to follow and a picture is worth a thousand words.

 

[eaglefire]

Because the last post was long and probably confusing to many (uses dreaded math) I took the formulas and used them to make the following picture based on several assumptions. Because of this the graph cannot be expected to produce accurate estimates of what range one will get with a particular trailer but rather give an idea of what the implications of increasing trailer weight and grade are when a trailer is towed.



View attachment 583



To use the graph find the intersection of the grade and trailer weight. Now look at the curves to the left and right of this and note the numbers on them. Multiply the number on the closest curve by the range of your CT without a trailer. For example if you have the 500 miles Trimotor and the closest curve is labeled 0.6 your estimate is 0.6*500 = 300. You can refine the estimate by interpolating between the two closest curves. For example, if your intersection lies half way between the 0.5 and 0.6 curves the factor is 5.5.

Because this is an attempt to simplify I'll refrain from discussing the assumptions or the implications of changing them but will be happy to respond to any questions.

This is a perfect tool to help with towing decisions and the impact we'll see with battery range. I'm good with math but certainly more of a visual learner. I saved this chart for a helpful summary of what to expect while towing my Airstream Travel Trailer. Thank you for taking the time to help and put together so much excellent data and information.

 

[hridge2020]

Heres your answer for towing..... Use this Tesla Vehicle.

 

[K Doc Brown 007]

Heres your answer for towing..... Use this Tesla Vehicle.

If the semi can tow 400+ miles, with an additional year of development.... why can’t the CT get close to that? ??‍

 

[Trencherman]

Battery pack option for the bed of the truck for range extender for towing. Would be great if the factory could make it plug and play.

 

[Alpeyev]

If the semi can tow 400+ miles, with an additional year of development.... why can’t the CT get close to that? ??‍

I bet you that semi aerodynamics with trailer are better than dragging a flat sail behind we call RV.

 

[azjohn]

If the semi can tow 400+ miles, with an additional year of development.... why can’t the CT get close to that? ??‍

I would expect the smaller Semi which the advertised range of pulling a semi trailer is 300 miles could pull a 5th wheel at least 400 miles. Problem might be the charging

 

[Saskateam]

What is the cost to purchase the semi vs the CT? I think you get extra range for extra cost with the semi. How far can the semi go when not towing?

 

[ajdelange]

If the semi can tow 400+ miles, with an additional year of development.... why can’t the CT get close to that? ??‍

Pulling the right load under the right conditions it can. But as the practical range of the CT is 400 miles with no trailer the "right load" is a very small one and the right conditions are downhill with a tail wind.

 

[azjohn]

What is the cost to purchase the semi vs the CT? I think you get extra range for extra cost with the semi. How far can the semi go when not towing?

300 mile Semi-$150K
500 mile Semi-$180K

So a lot more expensive

 

[ajdelange]

There is a Rivian forum that has a thread on what posters would like Rivian to add to their trucks. Thinking of trailering while looking at this particular thread it came to me that having a strain gauge on the hitch could be potentially valuable. As it is potentially valuable to the CT (and perhaps the Semi too) I thought I'd mention it here. Forgive the wee bit of math. F = m*a. F is the force on the trailer measured by the strain gauge, m is its mass and a the acceleration. When you pull away the tractor pulls the trailer with force F and accelerates by an amount a as measured by the odometer or a separate accelerometer (there is one in your smart phone). The ratio gives an estimate of the mass (gross weight) of the trailer. Knowing the weight makes better range estimation possible as the Telsa algorithm takes elevation changes into account. Knowing gross weight has safety implications and may be helpful in loading. WTH, I'm asking for one strain gauge. Why not ask for a second and have the CT display tongue weight as well?

E = F*x in which E is energy and x is distance traveled. From this we can get the Wh/mi consumed by the trailer which is at the heart of good range prediction. Having information Wh/mi data for the trailer will be as valuable in learning how one's trailer performs under various driving and weather conditions will be as valuable as that Wh/mi for the truck is for learning its performance characteristics.

Somebody Titter or Fleet (or whatever it is) Elon and ask for this!

 

[keyhere]

There is a Rivian forum that has a thread on what posters would like Rivian to add to their trucks. Thinking of trailering while looking at this particular thread it came to me that having a strain gauge on the hitch could be potentially valuable. As it is potentially valuable to the CT (and perhaps the Semi too) I thought I'd mention it here. Forgive the wee bit of math. F = m*a. F is the force on the trailer measured by the strain gauge, m is its mass and a the acceleration. When you pull away the tractor pulls the trailer with force F and accelerates by an amount a as measured by the odometer or a separate accelerometer (there is one in your smart phone). The ratio gives an estimate of the mass (gross weight) of the trailer. Knowing the weight makes better range estimation possible as the Telsa algorithm takes elevation changes into account. Knowing gross weight has safety implications and may be helpful in loading. WTH, I'm asking for one strain gauge. Why not ask for a second and have the CT display tongue weight as well?

E = F*x in which E is energy and x is distance traveled. From this we can get the Wh/mi consumed by the trailer which is at the heart of good range prediction. Having information Wh/mi data for the trailer will be as valuable in learning how one's trailer performs under various driving and weather conditions will be as valuable as that Wh/mi for the truck is for learning its performance characteristics.

Somebody Titter or Fleet (or whatever it is) Elon and ask for this!

If it went both ways you could use the strain gauge while braking/going downhill to maximize regen without sacrificing safety. Delaying when the trailer brakes are engaged to get that energy back but not so much that the trailer becomes a runaway train.

 

[ajdelange]

That is
A)An excellent suggestion
B)The basis for a very significant question: how will the braking signal to the trailer be managed if there is no strain gauge?

 

[Keeney]

The strain gauge can also measure the aero drag of the trailer at highway speed to use to help estimate range.

But you could also just measure how much current is being used to maintain steady state speed and extrapolate. No additional sensors need.