Charging on longer towing trips

[cvalue13]

Efficiency still matters when towing lol.

does it “matter” the relative efficiency of how a specific battery+motor conveys energy to the ground? Sure

but the commercially available vehicles are all extremely efficient at this - it’s the superpower of electric motors - such that these differ need in efficiency are perhaps notable at all at the level of EPA range and conditions

but those d Lars in efficiency are rounding errors compared to the forces involved in towing. The physics are just such that drag and rolling resistance are so overwhelming as the primary driver of resulting range that deltas in motor etc efficiency are reasonably not worth even mentioning.


Not to mention, people rarely discuss on one of the possible and seemingly paradoxical effects that can effect towing range:

The more aerodynamic the tow vehicle, the worse the range effects of adding a given trailer. Whereas less aerodynamic tow vehicles may have still significant but not as significant range hits from towing.

In truth, this is no paradox but instead an enigma. Because the reasons for this counterintuitive effect aren’t unknown, but just instead just surprising.

Basically, to use an example: a CT with 500mi EPA range achieves that range in part in virtue of it’s lower drag coefficient. if you took that same CT, and maden it’s body Lightning-shaped but kept its mechanicals constant, it’s EPA range would drop to - let’s call it - 350mi.

This initial reduction in range due to aerodynamics alone is caused by the Lightning-shaped CT busting up the air passing over it, whereas the CT-shaped CT cuts through.

But attach a trailer and what happens? The Lightning-shaped CT is effectively acting as a lead vehicle busting up the air in front of the trailer. It’s like the trailer is drafting behind a semi. In effect, the aerodynamic inefficiency of the lead vehicle acts to minimize the aerodynamic impact of the trailer. It’s why the Lightning-shaped CT starts with only 350 mi range - it’s already busting up a bunch of air.

But for the CT-shaped CT, it’s 500mi range is due to it cutting through the air far better. The trailer is no longer drafting behind a semi, it’s drafting behind a sports car.

Point being, people often incorrectly assume that aerodynamics of the CT and its resulting EPA max range of 500mi means it will perform better at towing range than competitors. That may be true at a net milage range level, but it’s % range reduction due to drag may be worse than a Lightning, all else equal.

This sort of enigma being in play, as just one example, means that not only could “efficiency” of motors etc without a trailer be a rounding error when it comes to the physics of towing, the superior aerodynamics of the CT and that “efficiency” can actually end up being a relative negative to its towing performance compared to less aerodynamic comparisons.

To the extent a Lightning’s trailer is drafting behind a semi while the CT’s trailer is drafting behind a sports car, the latter’s typical “efficiencies” end up being disproportionately effected.

It’s a wait and see.

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[Crissa]

Rivian just bought it. It may remain as an app, dont know.

Rivian has no plans to make them stop supporting other vehicles, their CEO has clarified.

-Crissa

 

[ldjessee]

I am hoping with Rivian, Ford, and soon Tesla and others, that trailer manufacturers will realize that they need to make their trailers fit within the shadow of the tow vehicle better, be more aerodynamic, and definitely work putting the air back behind them (drag).

Most trailers are literally a brick in shape and ratio.

Even an Airstream is not as aerodynamic as it could be. Many small 'teardrop' trailers also have aerodynamic issues, but are atleast better than boxes on wheels.

The Bowlus Road Chief is better than most, but using a collapse down method like a lot of popup or even that lightship RV would help tuck it into the vehicles 'shadow'.

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