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I have a fairly heavy wake boat that clocks in around 8000 pounds on the trailer when full of gas and gear. Anyone tried towing anything similar with their R1T? I have seen a video where they lost > 50% towing something is similar weight, but it was a box so not as aerodynamic.

Thank you in advance!
 

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A lot depends on towing speed... not too much of a range impact on low speed local road towing, but once you start moving at highway and limited access road speeds that's when you see the aerodynamic hit on range.

How far are you towing and at what speeds?
 

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I've been following the issue of towing and range closely as I have a small teardrop camper to haul, usually to more remote places. The amount of information on the subject is not yet huge, but it is growing, and there is some data that appears pretty reliable.

From what I've seen, weight is a very secondary factor to aerodynamic drag. The Out of Spec guys did a test with a heavily laden utility trailer, then repeated with the same trailer emptied, but with a sheet of plywood fastened vertically. I don't recall the precise numbers OOS reported, but they were much worse with the plywood blocking the wind (around 0.8 mi/kWh I believe). There have also been other folks who posted data from their travel trailer towing with the R1T. One recent video was of a family towing their 8,000 lb, 40 foot Airstream from NE to CO; they reported an average of about 1.2 mi /kWh. And of course there is the Rivian towing test with a box trailer near the max tow weight of the R1T that was reported to cut the range by 50%, which I believe is in just north of the area of 1.0 mi/kWh.

The best course may be to plan for a 50% reduction, maybe a bit more, for most towing unless it's a low-drag load, like a very small teardrop or pop-up camper that rides very low. Of course, towing in hot or cold weather, in heavy winds, and at elevation will reduce range, perhaps below the 50% level.

If you are planning to tow with 135 kWh LR, you'd be looking at a max theoretical range of perhaps 150 miles. Keeping to 80/20 SOC parameters means an effective range of maybe 100 miles. I'm hoping to do a bit better than the Airstream family since my [email protected] 320 is smaller and more rounded. Still, even if do, and even with the 180 kWh Max Pack (my current configuration), I'm looking at an effective range of 130 - 140 miles. That's enough to comfortably cover trips where the charging infrastructure is reasonably robust, but not nearly enough to traverse much of Canada or the more remote parts of the US. I'm hoping that by the time my R1T Max gets delivered (guessing early 2024 despite Rivian saying 2023), the charging network will have expanded considerably and become more reliable.
 

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the charging network will have expanded considerably and become more reliable.
50% hit with towing is always going to be an issue with EV's. Best solution for long range towing for EV's is the trailers being built with batteries and electric motors to take the load and provide aux power. Now dumping the boat trailer with batteries might be an issue but we do see Tesla's driving in crazy deep water. Advantage with the powered boat trailer is providing booster for EV boats like Candela C8.

This Camper With 240-kWh Battery, Twin Motors Is An Electric Car Owner's Dream
 

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I have a fairly heavy wake boat that clocks in around 8000 pounds on the trailer when full of gas and gear. Anyone tried towing anything similar with their R1T? I have seen a video where they lost > 50% towing something is similar weight, but it was a box so not as aerodynamic.

Thank you in advance!
As others have mentioned, when you do tow your boat you should prepare to get half of whatever your normal range. If you end up getting better mileage than that it's a bonus.
 

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I will say, when I pulled the 26ft 6500# travel trailer, I only went 35 miles. However, it was a total 600ft incline. About 4 miles city. I started with 88 miles and ended with 58. So the truck overestimated my usage. Now, bear in mind that it has no idea what's on the back. It automatically uses a 50% when you switch from all-purpose. I did find right away that when it comes to breaking/stopping it's best to let the Regen take it hard as you can let it, rather than slow stops. It seems to regenerate more the more friction you'll let them take at once.
 

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I have a fairly heavy wake boat that clocks in around 8000 pounds on the trailer when full of gas and gear. Anyone tried towing anything similar with their R1T? I have seen a video where they lost > 50% towing something is similar weight, but it was a box so not as aerodynamic.

Thank you in advance!
I just towed my 7000+ lb boat from Monterey CA to Lake Tahoe, CA - about 310 miles. I was hoping for only a 50% range reduction, but I lost about 66% of my range, leaving roughly 110 miles per charge. I drove 50-65 mph. I had to charge 5 times to make it (charging at 70-95%, depending on the next EA station). I slowed to 50 mph to conserve as much as possible while driving up through the Sierra mountains on HWY 80. It was a little stressful coming over Donner Pass with less than 24 miles of range left.

The R1T did an amazing job towing, but consumed the battery pretty quickly. Temp was about 77 deg F and I had periods of heavy traffic. I didn’t have my aero covers on my 21’’ wheels which might have impacted my mileage. I think I averaged about 0.88 miles/KW. The trip took about 3 hours longer than normal, but on a positive note, it was cheaper than buying 3 tanks of gas, which was typical with my Ram 1500 for the same trip. I’ve also done some towing with a 3000 lb dump trailer this past week in the Lake Tahoe basin and the mileage has been significant better.

I still love this truck, but it was painful making so many stops.

hope this helps!
 

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I was hoping for only a 50% range reduction, but I lost about 66% of my range, leaving roughly 110 miles per charge. I drove 50-65 mph.
That's from sea level to 6,000 ft at Tahoe so be interesting to see what you get towing back down to Monterey. 66% for that climb seems reasonable for 8k#.

Sounds like the EA stations all worked well.
 

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I just towed my 7000+ lb boat from Monterey CA to Lake Tahoe, CA - about 310 miles. I was hoping for only a 50% range reduction, but I lost about 66% of my range, leaving roughly 110 miles per charge.

. . . I think I averaged about 0.88 miles/KW. The trip took about 3 hours longer than normal, but on a positive note, it was cheaper than buying 3 tanks of gas, which was typical with my Ram 1500 for the same trip. I’ve also done some towing with a 3000 lb dump trailer this past week in the Lake Tahoe basin and the mileage has been significant better.

I still love this truck, but it was painful making so many stops.

hope this helps!
Another good data point @kipevans, thanks for posting.

The figure you averaged is consistent with what the OOS aero test returned; they too got much better mileage when towing a heavy load that did not stick up above the tailgate, kind of similar to your towing the dump trailer. Hopefully, the 0.88 mi/kWh you got is the bottom of the range.

What's become pretty clear is that towing successfully with the Rivian, or any BEV, depends to large extent on the charging network. It's admittedly a pain to have to stop frequently to recharge, but not having a charging station available when needed kind of puts the kibosh on your whole trip.
 

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That's from sea level to 6,000 ft at Tahoe so be interesting to see what you get towing back down to Monterey. 66% for that climb seems reasonable for 8k#.

Sounds like the EA stations all worked well.
Yay, another chance to dust off the physics text book! I'm always surprised at how "uncalibrated" my brain is about these towing elevation gain/loss scenarios. My first reaction is also to think that this one-way net elevation gain must represent a huge amount of potential energy that has to be accounted for. But then when you run the numbers, its always much less impressive somehow.
6000 elevation gain for the 7000lbs trailer = 16kWh of potential energy gain by the trailer
add the 7100lbs of the R1T and another 500lbs cargo brings the total to 13,600lbs = 31 kWh
If you assume 80% power conversion efficiency (wild guess?) then you used 38 kWh from the battery for ONLY the elevation change. That's only 8.6% of your 358 kWh used for the trip. So a flat tow for the same distance and speed should only be 8.6% less kWh.

It also means the most regen recovery you will get on the way back down is 0.8 * 31 = 24.8 kwh.

Please pick this apart if i'm making some really dumb assumptions here....

Kirk
 

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Yay, another chance to dust off the physics text book! I'm always surprised at how "uncalibrated" my brain is about these towing elevation gain/loss scenarios. My first reaction is also to think that this one-way net elevation gain must represent a huge amount of potential energy that has to be accounted for. But then when you run the numbers, its always much less impressive somehow.
6000 elevation gain for the 7000lbs trailer = 16kWh of potential energy gain by the trailer
add the 7100lbs of the R1T and another 500lbs cargo brings the total to 13,600lbs = 31 kWh
If you assume 80% power conversion efficiency (wild guess?) then you used 38 kWh from the battery for ONLY the elevation change. That's only 8.6% of your 358 kWh used for the trip. So a flat tow for the same distance and speed should only be 8.6% less kWh.

It also means the most regen recovery you will get on the way back down is 0.8 * 31 = 24.8 kwh.

Please pick this apart if i'm making some really dumb assumptions here....

Kirk
This is great! I love it when we see physics in action :)

Regarding this: "If you assume 80% power conversion efficiency"
In this context, there's no need to assume anything about power conversion efficiency, which in the end is a function of all of your drivetrain and driving parameters. Best to forget about that when you're talking about what it takes to go uphill, and what you get back when going downhill. Why? Because on the uphill you must spend the energy to lift the whole mess, which is those 38kWh you calculated. On the downhill (and I've done this many many times with my I-Pace) you get ~90-95% of that energy back because electric motor!
 

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Another good data point @kipevans, thanks for posting.

The figure you averaged is consistent with what the OOS aero test returned; they too got much better mileage when towing a heavy load that did not stick up above the tailgate, kind of similar to your towing the dump trailer. Hopefully, the 0.88 mi/kWh you got is the bottom of the range.

What's become pretty clear is that towing successfully with the Rivian, or any BEV, depends to large extent on the charging network. It's admittedly a pain to have to stop frequently to recharge, but not having a charging station available when needed kind of puts the kibosh on your whole trip.
If you are not towing long distances every day, the R1T is great. Driving from your house to the harbor, no problem. Need to drive up to the lake 50 miles away, you can do it on a full charge round trip without issue. If you are towing up hill for long distances plan on spend time charging along the way. In California it’s pretty easy to find fast chargers that make life much easier. I used 350
kwh EA chargers during my trip.
 

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Yay, another chance to dust off the physics text book! I'm always surprised at how "uncalibrated" my brain is about these towing elevation gain/loss scenarios. My first reaction is also to think that this one-way net elevation gain must represent a huge amount of potential energy that has to be accounted for. But then when you run the numbers, its always much less impressive somehow.
6000 elevation gain for the 7000lbs trailer = 16kWh of potential energy gain by the trailer
add the 7100lbs of the R1T and another 500lbs cargo brings the total to 13,600lbs = 31 kWh
If you assume 80% power conversion efficiency (wild guess?) then you used 38 kWh from the battery for ONLY the elevation change. That's only 8.6% of your 358 kWh used for the trip. So a flat tow for the same distance and speed should only be 8.6% less kWh.

It also means the most regen recovery you will get on the way back down is 0.8 * 31 = 24.8 kwh.

Please pick this apart if i'm making some really dumb assumptions here....

Kirk
Hi Kirk:

I love your post! I’m also a science nerd, but my college education is marine bio, not physics. Looking at your numbers your additional is off by 1000lbs. Should be 14,600lbs, not 13,600lbs-right? But, what’s really interesting if your power conversion calculation for the elevation gain-which is so cool. I need to do the math too, but in California, we are mostly flat through the central valley until we hit the California Sierra - its not a linear progression from sea level to 6200’. There are several small passes that will eat your battery. If you look on a map, Monterey CA & Sacramento CA, have less than 100ft of elevation difference.

To be honest, my R1T battery was impacted substantially between Monterey and San Jose,CA. There is no way to sugar coat this. I pulled out of my driveway with 167 miles of range and it dropped to 110 miles within 15 mins. I had to charge 100 miles later in San Jose. Reality set in and I altered my charging plans from 3 to 5 stops in order to reach Lake Tahoe from Monterey Bay. But, these were not full charging stops. I would charge for 30 mins and then get going again. In Rocklin CA I went to 90% charge because I wanted a full battery heading into the Sierra. What you need to know is that in the final 75+ miles there is serious elevation gain. Most of the 6200ft is in the last 70 miles and you actually drive over a pass at 7000’. It will eat your fuel, or battery-doesn’t matter.

I know this sound like a major hassle, but I’m OK with it. Yes, it was brutal stopping 5 times (unhooked my boat 4 times) to charge, but I’m not doing this every week. I spent less than $70 bucks charging during my trip. If I had used my Ram 1500 it would have been over $350 in fuel.

In addition, I drove home from Tahoe last week and I can drive home without the boat on one charge-very cool!

Lastly, I’ve realized during my three weeks of ownership that I really, really, love this truck. If my towing description has anyone scarred, please keep in mind that there is so much more to love here. This is an amazing truck with a lot more to offer than towing. If you haven’t taken delivery yet, you will be blown away. Towing heavy loads uphill is only a small metric for the capability for the R1T.
 

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Hi Kirk:

I love your post! I’m also a science nerd, but my college education is marine bio, not physics. Looking at your numbers your additional is off by 1000lbs. Should be 14,600lbs, not 13,600lbs-right? But, what’s really interesting if your power conversion calculation for the elevation gain-which is so cool. I need to do the math too, but in California, we are mostly flat through the central valley until we hit the California Sierra - its not a linear progression from sea level to 6200’. There are several small passes that will eat your battery. If you look on a map, Monterey CA & Sacramento CA, have less than 100ft of elevation difference.

To be honest, my R1T battery was impacted substantially between Monterey and San Jose,CA. There is no way to sugar coat this. I pulled out of my driveway with 167 miles of range and it dropped to 110 miles within 15 mins. I had to charge 100 miles later in San Jose. Reality set in and I altered my charging plans from 3 to 5 stops in order to reach Lake Tahoe from Monterey Bay. But, these were not full charging stops. I would charge for 30 mins and then get going again. In Rocklin CA I went to 90% charge because I wanted a full battery heading into the Sierra. What you need to know is that in the final 75+ miles there is serious elevation gain. Most of the 6200ft is in the last 70 miles and you actually drive over a pass at 7000’. It will eat your fuel, or battery-doesn’t matter.

I know this sound like a major hassle, but I’m OK with it. Yes, it was brutal stopping 5 times (unhooked my boat 4 times) to charge, but I’m not doing this every week. I spent less than $70 bucks charging during my trip. If I had used my Ram 1500 it would have been over $350 in fuel.

In addition, I drove home from Tahoe last week and I can drive home without the boat on one charge-very cool!

Lastly, I’ve realized during my three weeks of ownership that I really, really, love this truck. If my towing description has anyone scarred, please keep in mind that there is so much more to love here. This is an amazing truck with a lot more to offer than towing. If you haven’t taken delivery yet, you will be blown away. Towing heavy loads uphill is only a small metric for the capability for the R1T.
Hi Kirk - have you driven up to Tahoe without a boat yet? Single Charge?

thx
 

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Hi Kirk - have you driven up to Tahoe without a boat yet? Single Charge?

thx
On a full battery I did not need to charge from Tahoe to Monterey - 310 miles. I had 24 miles remaining. On the way up to Tahoe from Monterey I made one stop in Rocklin for 15 - 20 mins to add miles for the elevation gain. I'm pretty happy with the performance. Towing a heavy boat is a different story, but I can deal with the multiple stops once or twice a year.
 

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On a full battery I did not need to charge from Tahoe to Monterey - 310 miles. I had 24 miles remaining. On the way up to Tahoe from Monterey I made one stop in Rocklin for 15 - 20 mins to add miles for the elevation gain. I'm pretty happy with the performance. Towing a heavy boat is a different story, but I can deal with the multiple stops once or twice a year.
Thank you. I switched my order today to get one sooner. I think I could make Truckee from Santa Cruz on a single charge. Time will tell. Thanks again
 
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