New towing update still needs some work

[av8or]

I towed the camper ~260 miles on Sunday and while the GOM was better than before, it’s still gets baffled when it comes to simple math. After towing for 4.5 hours at 1.0 m/kWh the truck still thinks I can go over 180 miles on a full charge, and the range at arrival is still overly optimistic. Never mind the ? looking at you.

Sponsored

 

[HyperionMark]

Weird. I had slightly more accurate towing estimates, but still slightly off. I have my little trip report on the main post-update towing thread.
Was it a true round trip elevation-wise? Maybe if it was uphill you got a little lower efficiency numbers but the 100% range estimate is based on level terrain. And maybe the same could be said about a headwind. Or maybe you were traveling interstate speeds and it factors the range on more like 60ish mph? Just guesses though.

 

[av8or]

It was not a loop style test, just had to go from Portland to Medford Oregon with the trailer. I will be doing the reverse on Friday and I’m deliberating if I want to reset it or if I should let it go and see if it gets closer over time. I kept speeds at 60-65 for the entire trip. It just seems odd to get 1.0 m/kWh for almost 5 hours, but the truck still thinks I can go 187 miles on a 130 kWh pack.

 

[HyperionMark]

It was not a loop style test, just had to go from Portland to Medford Oregon with the trailer. I will be doing the reverse on Friday and I’m deliberating if I want to reset it or if I should let it go and see if it gets closer over time. I kept speeds at 60-65 for the entire trip. It just seems odd to get 1.0 m/kWh for almost 5 hours, but the truck still thinks I can go 187 miles on a 130 kWh pack.

That's quite an elevation increase. So I think what they are doing is actually smart. They are showing actual experienced efficiency but showing 100% range based on flat terrain at probably 60 mph or so.

I'd let it go back downhill and see how things change if I were you. Will be interesting to see. For science!

 

[MrMusAddict]

I have a suspicion. I think for each trailer you save they essentially build a 3D profile of efficiency vs speed vs grade. So for example, after feeding it some data, it will know:

• At 25 MPH on flat ground, you might get 2 mi/kWh (aero is minimal here, so this is used to estimate weight)
• At 65 MPH on flat ground, you might get 1.25 mi/kWh
• At 65 MPH on a 4% grade, you might get 0.3 mi/kWh

Here's a rudimentary visualization of this concept:

What I think Rivian is doing is, they ignore your average context. By that I mean, if you regularly drive it at 70 MPH and your route is very hilly (start/end same elevation, but you climb/descend a lot), you'll always get 1.0 mi/kWh.

But my suspicion is, Rivian doesn't know what your NEXT drive will be, so they gotta pick somewhere on this chart to estimate range. I'd assume it's whatever they calculate your efficiency would be at around 45 MPH and 0% grade (which may be 1.45 mi/kWh).

The good news is, this 3D data set can be applied in their navigation. They know speed limits, and they know climb/descent. So if you navigate somewhere and it's incorrect, then likely there's some data missing on the map (very common).

 

[MrMusAddict]

It was not a loop style test, just had to go from Portland to Medford Oregon with the trailer. I will be doing the reverse on Friday and I’m deliberating if I want to reset it or if I should let it go and see if it gets closer over time. I kept speeds at 60-65 for the entire trip. It just seems odd to get 1.0 m/kWh for almost 5 hours, but the truck still thinks I can go 187 miles on a 130 kWh pack.

To supplement my response above with the context of your upcoming drive from Medford → Portland, that trip is a net descent, although assuming you're coming up the I5 there's a ton of climbing to go over Sexton (which fun/immature fact, the summit is at milepost 69), and just constant up/down until you're near Eugene.

That being said, I know for certain the speed limits & climb/descent is well-logged on the I5. So I recommend you hop in your truck and test-navigate to Portland to verify it's closer to what you expect.

Sponsored