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whiterock2000

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UPDATE: Nov 18, 2022. I've added in some new data from trips in colder weather (23F is coldest so far). I also added a chart showing %-loss in range due to temperature using 70 Deg F as the baseline point. It is important to note that these efficiency number are based on a trip of 3 hours in length. If you are doing shorter trips the effect of temperature will be much stronger because the battery won't have had time to warm up and operate more efficiently. I will say I find the effect of temperature to be less than I was expecting (15% loss at 32F) and the effect of the bike rack to be larger than I was expecting.



I make a regular road trip from our home near Minneapolis, MN to our cabin near Hayward, WI. It's about 165 miles each way. I always take the same route and go about the same speed. Set cruise control at 70 mph while on I-35 and then go about 60 mph on the state highways across Wisconsin.

1664797682064.png


Always in conserve mode at "Low" ride high. I have 21" road tires. The average speed is between 50 and 55 mph each time (going through a number of small towns along the way quickly drops the average speed well below the cruising speed of 60 to 70 mph).

Sometimes I've done the trip with a hitch mounted bike rack with 1 or 2 bikes loaded. Most of the time my truck makes the trip "naked" with no mounted gear on the bed or hitch. The range/efficiency numbers are very consistent and show a clear trend with temperature and the effect of the bike rack. The bike rack cuts the efficiency by about 10%. The temperatures on the graph are a rough estimate of the average temperature during the trip.

I will continue to update this as we head into winter and colder temperatures. The shaded areas on the graphs are the 95% confidence interval on the 2nd order curve fit to the data.

View attachment 36371

Assuming a 125 kWh battery pack, the full pack range would be as shown below.
View attachment 36372


Calculating the percent change in range/efficiency from a 70 Deg baseline; The percent loss in range due to temperature is the same with and without a bike rack which makes sense.
View attachment 36374
Thank you for collecting and sharing this. Very helpful!
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I haven't done nearly at detailed logging, but I have both a hitch bike rack and the one up rack which goes on the bed rails. I see a dramatic difference between the two. The one up rack on the cargo bars has much more drag and will pull me down to 1.5 miles/kwh vs 2.0 miles/kwh on the hitch rack. It's clear to me the bike being higher up is causing more wind drag.

I use the one up rack for close mountain bike rides since it doesn't block my rear view camera or affect the backup sensors.. but if I go on a trip I use the hitch mounted rack instead.

I also have a iKamper hard shell that I use with the hitch bike rack at the same time. I need to do some runs with and without to see if that helps or hurts the aerodynamics.
 
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I haven't done nearly at detailed logging, but I have both a hitch bike rack and the one up rack which goes on the bed rails. I see a dramatic difference between the two. The one up rack on the cargo bars has much more drag and will pull me down to 1.5 miles/kwh vs 2.0 miles/kwh on the hitch rack. It's clear to me the bike being higher up is causing more wind drag.

I use the one up rack for close mountain bike rides since it doesn't block my rear view camera or affect the backup sensors.. but if I go on a trip I use the hitch mounted rack instead.

I also have a iKamper hard shell that I use with the hitch bike rack at the same time. I need to do some runs with and without to see if that helps or hurts the aerodynamics.
Good info on the two bike mounting methods. I’ve done one trip with a Thule tent on the cross bars and the impact was not that much.
 
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UPDATED: Dec 26, 2022. I updated the graphs on the first posting to add a data point at 0 deg F. This 0 Deg F data point is in "Snow Mode", not conserve like the other datapoints. Roads were partially snow covered so this data point is probably a low estimate of what a trip in conserve mode would be. I've also added an extrapolation line to estimate what the range/efficiency would be below 0 Deg F.

Newest set of charts also included in this post.
Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T efficiency vs tem

Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T range vs tem

Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T percent change vs tem
 

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UPDATED: Dec 26, 2022. I updated the graphs on the first posting to add a data point at 0 deg F. This 0 Deg F data point is in "Snow Mode", not conserve like the other datapoints. Roads were partially snow covered so this data point is probably a low estimate of what a trip in conserve mode would be. I've also added an extrapolation line to estimate what the range/efficiency would be below 0 Deg F.

Newest set of charts also included in this post.
R1T efficiency vs temp.jpg

R1T range vs temp.jpg

R1T percent change vs temp.jpg
Wonderful data, thank you! How well do you control for tire pressure? In other words, how close is the pressure to 48psi on each of those trips?
 

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Wonderful data, thank you! How well do you control for tire pressure? In other words, how close is the pressure to 48psi on each of those trips?
Good question on tire pressure. I inflated once in the fall when the temp's were in the 40's. During my trip a 0 Deg F the onboard tire pressure monitor said the tires were around 43 to 44 PSI.
 

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Great information. Thanks @Budman!
 
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Updated the original post at the start of this thread and repeating the update here to make it easier to find;


UPDATED JULY 17, 2023: Added in a lot more data including doing this trip in All Purpose Mode with no mounted gear and in Conserve Mode with a bed top tent. For the conditions of this testing see the full introduction to at the start of this thread. New graphs attached within this July 17 Update section. The attached photo shows my truck with the roof top tent and bike rack I have. The data shown in these graphs is for just the tent alone or bike rack alone, never both together.

Only 2 data points doing this trip with the tent so no confidence intervals for that but it is looking like it has more impact on range than the bike rack. All purpose mode with no gear likely has lower efficiency than conserve mode with a tent or bike rack. The mounted gear reduces the range/efficiency by about 15%.

The effect of temperature is about 0.5% change per degree F.

Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data Screenshot 2023-07-17 at 8.54.40 AM
Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T efficiency vs tem
Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T range vs tem
Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T percent change vs tem
 

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According to the graph you have actually reached 3 miles/kwh on one occasion? And a number of occasions above 2.8 miles/kwh?

Is that correct?
 
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According to the graph you have actually reached 3 miles/kwh on one occasion? And a number of occasions above 2.8 miles/kwh?

Is that correct?
That is correct. For me, on that route, over that distance, at that speed (54 mph avg, 70 mph freeway cruising), at that temperature. I’ve seen 3.0 average efficiency. Your result may very 😎
 

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Be interested in what efficency you get with RTT and Bikes.
Our recent roadtrip Seattle>Bend>Crater>Tahoe>Bend>Seattle I got 2.11 over 2,000 miles w/ 22s and RTT+Bikes (hitch rack). 75-85 on interstates. I did add PPF over the rear cab spoiler aero holes. No idea if it helped.
 

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This is interesting. Why do people thing range/efficiency increases with temperature? I would assume the curve to look like an upside down U where efficiency goes down when heat or AC is being used and peaks when AC/heat isn’t being used. Of course you don’t have enough low temp data yet, but very interested to see what that looks like!
I know this is an old thread/post, but I know it's being updated some times so figured I would toss this in: Another very important reason for the increased efficiency at higher temps is that air gets less dense as the temperature increases. EVs are very sensitive to air resistance given their very high efficiency, so it has a noticeable impact on range. This change is not sensitive to heat or AC use.
 

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UPDATED JULY 17, 2023: Added in a lot more data including doing this trip in All Purpose Mode with no mounted gear and in Conserve Mode with a bed top tent. For the conditions of this testing see the full tread below. New graphs attached within this July 17 Update section. The attached photo shows my truck with the roof top tent and bike rack I have. The data shown in these graphs is for just the tent alone or bike rack alone, never both together.

Only 2 data points doing this trip with the tent so no confidence intervals for that but it is looking like it has more impact on range than the bike rack. All purpose mode with no gear likely has lower efficiency than conserve mode with a tent or bike rack. The mounted gear reduces the range/efficiency by about 15%.

Screenshot 2023-07-17 at 8.54.40 AM.png

R1T efficiency vs temp.jpg
R1T range vs temp.jpg
R1T percent change vs temp.jpg


UPDATED: Dec 26, 2022. Added in a data point at 0 deg F. This data point is in "Snow Mode", not conserve like the other datapoints. Roads were partially snow covered so this data point is probably a low estimate of what a trip in conserve mode would be. I've also added an extrapolation line to estimate what the range/efficiency would be below 0 Deg F.

UPDATE: Nov 18, 2022. I've added in some new data from trips in colder weather (23F is coldest so far). I also added a chart showing %-loss in range due to temperature using 70 Deg F as the baseline point. It is important to note that these efficiency number are based on a trip of 3 hours in length. If you are doing shorter trips the effect of temperature will be much stronger because the battery won't have had time to warm up and operate more efficiently. I will say I find the effect of temperature to be less than I was expecting (15% loss at 32F) and the effect of the bike rack to be larger than I was expecting.



I make a regular road trip from our home near Minneapolis, MN to our cabin near Hayward, WI. It's about 165 miles each way. I always take the same route and go about the same speed. Set cruise control at 70 mph while on I-35 and then go about 60 mph on the state highways across Wisconsin.

1664797682064.png


Always in conserve mode at "Low" ride high. I have 21" road tires. The average speed is between 50 and 55 mph each time (going through a number of small towns along the way quickly drops the average speed well below the cruising speed of 60 to 70 mph).

Sometimes I've done the trip with a hitch mounted bike rack with 1 or 2 bikes loaded. Most of the time my truck makes the trip "naked" with no mounted gear on the bed or hitch. The range/efficiency numbers are very consistent and show a clear trend with temperature and the effect of the bike rack. The bike rack cuts the efficiency by about 10%. The temperatures on the graph are a rough estimate of the average temperature during the trip.

I will continue to update this as we head into winter and colder temperatures. The shaded areas on the graphs are the 95% confidence interval on the 2nd order curve fit to the data.


R1T efficiency vs temp.jpg



Assuming a 125 kWh battery pack, the full pack range would be as shown below.
R1T range vs temp.jpg



Calculating the percent change in range/efficiency from a 70 Deg baseline; The percent loss in range due to temperature is the same with and without a bike rack which makes sense.
R1T percent change vs temp.jpg
Someone knows how to present information effectively! Very well done. (Seaborn?)
 
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Budman

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Someone knows how to present information effectively! Very well done. (Seaborn?)
Thanks for the kind words. The graph below is my most recent data update showing the difference in efficiency between All Purpose and Conserve modes. Some unexpected behavior with temperature! Below 40 degrees Conserve and All Purpose have been giving the same performance.

Rivian R1T R1S UPDATED July 17, 2023: Rivian R1T Road Trip Range vs Temperature  - Data R1T efficiency vs tem
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