[Yossarian]

I've posted fairly often regarding range and towing, and why I believe I need the Max battery pack to be able to successfully tow even my smaller teardrop over longer distances. There is still not a huge amount of data available regarding power consumption and range for Rivian towing, and most of what I've seen is based on towing larger, bulky loads. Their consumption figures are not encouraging, with most at or even below 1.0 mi/kWh. There is a Youtube video of a family towing a 30' Airstream with an R1T that was encouraging however. The figures they posted were in the 1.3 m/kWh range.

I recently had a on-line dialog on another website with someone towing a teardrop that is similar in design to mine, though quite a bit longer, wider, higher and heavier. Their tow vehicle is a Tesla Model Y, and they report consumption averaging 370 watts per kilometer. If I'm doing the conversion properly, that would be about 592 watts/mile and would in turn mean a theoretical max range with a Rivian LR Large pack of 228 miles. Using 80/15 charge/discharge parameters brings effective range down quite a bit, but still to a very respectable 150 miles.

Am I making a mistake in my calculations? As importantly, am I making a mistake using the Tesla as the basis for things? I'd think that the larger and heavier Rivian, regardless of whether it was the R1T or R1S, would better the Model Y, or at least be no worse. With my teardrop being smaller and 1,000 lbs lighter than the one towed by the Model Y, I'd also think that at the least, using the Tesla figures would be very conservative.

The bottom line for me is that if I could get those numbers towing my [email protected] 320 with a Rivian LR Large pack, I'd gladly forgo the wait (which could be indefinite) for the Max to become available.

 

[LoudMusic]

While driving about 350 miles this morning in our Model Y, my wife and I discussed using our pending R1T as a tow vehicle for a 9,000 lb camper trailer. Everything I've read said the range comes down to about 135 miles. Our goal would be to primarily move it less than 100 miles and set up shop again at another RV campground and charge overnight on 50A before continuing on the next day, with maybe occasional stops for fast charging to make bigger than 100 mile hops. But that would be 100% charge sessions which take upwards of an hour, opposed to the 15 to 20 minute stops we make in the Tesla to add 150 miles back and get to the next fast charger.

A lightweight teardrop is definitely going to be better. But air drag is the big enemy and even though it's obviously superior, you're still dragging a giant wall behind your tow vehicle. I suspect 150 miles is a fair assessment. And the max battery (which could be indefinite) would likely only add another 15 to 20 miles.

I'd get the large battery and see how it goes. If you can spare the cash maybe make a second order for a max battery and trade/sell the first one if it doesn't work out or cancel the max order if the large is good enough.

 

[FanFLelectric]

I've posted fairly often regarding range and towing, and why I believe I need the Max battery pack to be able to successfully tow even my smaller teardrop over longer distances. There is still not a huge amount of data available regarding power consumption and range for Rivian towing, and most of what I've seen is based on towing larger, bulky loads. Their consumption figures are not encouraging, with most at or even below 1.0 mi/kWh. There is a Youtube video of a family towing a 30' Airstream with an R1T that was encouraging however. The figures they posted were in the 1.3 m/kWh range.

I recently had a on-line dialog on another website with someone towing a teardrop that is similar in design to mine, though quite a bit longer, wider, higher and heavier. Their tow vehicle is a Tesla Model Y, and they report consumption averaging 370 watts per kilometer. If I'm doing the conversion properly, that would be about 592 watts/mile and would in turn mean a theoretical max range with a Rivian LR Large pack of 228 miles. Using 80/15 charge/discharge parameters brings effective range down quite a bit, but still to a very respectable 150 miles.

Am I making a mistake in my calculations? As importantly, am I making a mistake using the Tesla as the basis for things? I'd think that the larger and heavier Rivian, regardless of whether it was the R1T or R1S, would better the Model Y, or at least be no worse. With my teardrop being smaller and 1,000 lbs lighter than the one towed by the Model Y, I'd also think that at the least, using the Tesla figures would be very conservative.

The bottom line for me is that if I could get those numbers towing my [email protected] 320 with a Rivian LR Large pack, I'd gladly forgo the wait (which could be indefinite) for the Max to become available.

If you have been towing an RV for a long time as we did in the 70's and 80's, you know you have two or three issues. Wind resistance, weight to accelerate and move uphill, and rolling resistance from the tires of the trailer. Depending on how level the area you are crossing is, the weight of the tow will be factor. The direction and velocity of the wind conditions along the route will vary each trip in each direction. I suggest that projecting consumption will be difficult. While your trips by ICE vehicles may have been a run for the hills after work on Friday, Going slower so you can go farther may be the answer you have not considered. You probably already know that the faster you go the more force is required to overcome drag. Rivian is not as aerodynamic as any Tesla. Thus range will be much better at 55 mph than at 75 mph.
It was not difficult for us to forgo the max pack, we prefer not to move around the extra battery weight every time we move the Rivian, once we get it.

 

[LoudMusic]

If you have been towing an RV for a long time as we did in the 70's and 80's, you know you have two or three issues. Wind resistance, weight to accelerate and move uphill, and rolling resistance from the tires of the trailer. Depending on how level the area you are crossing is, the weight of the tow will be factor. The direction and velocity of the wind conditions along the route will vary each trip in each direction. I suggest that projecting consumption will be difficult. While your trips by ICE vehicles may have been a run for the hills after work on Friday, Going slower so you can go farther may be the answer you have not considered. You probably already know that the faster you go the more force is required to overcome drag. Rivian is not as aerodynamic as any Tesla. Thus range will be much better at 55 mph than at 75 mph.
It was not difficult for us to forgo the max pack, we prefer not to move around the extra battery weight every time we move the Rivian, once we get it.

"weight to accelerate and move uphill"

Which should each be at least partially recoverable by an EV, lessening (but not eliminating) their effects, yeah?

What are you planning to tow with your Rivian?

 

[sciencegeek]

I suspect that the weight of the trailer will make a huge difference. The added rolling resistance (in the most general sense, including loss due to tire deformation) and the losses in acceleration (much more power needed to get going) is probably more important than the additional drag (if you're at reasonable speeds).

Also, an 'advantage' of the R1 is that its cross sectional area is quite large, so it hides more of the trailer compared to a MY.

Bottom line is that I would expect less than 50% range reduction if the trailer isn't super heavy (like that 9000 lbs beast that was mentioned) or bulky.

 

[LoudMusic]

I suspect that the weight of the trailer will make a huge difference. The added rolling resistance (in the most general sense, including loss due to tire deformation) and the losses in acceleration (much more power needed to get going) is probably more important than the additional drag (if you're at reasonable speeds).

Also, an 'advantage' of the R1 is that its cross sectional area is quite large, so it hides more of the trailer compared to a MY.

Bottom line is that I would expect less than 50% range reduction if the trailer isn't super heavy (like that 9000 lbs beast that was mentioned) or bulky.

Pretty much all prior evidence is to the contrary. Drag is vastly more critical than weight. And in most cases the additional losses incurred by getting the additional mass rolling are largely recouped during deceleration through regenerative braking.

 

[electricavenue]

I suspect that the weight of the trailer will make a huge difference. The added rolling resistance (in the most general sense, including loss due to tire deformation) and the losses in acceleration (much more power needed to get going) is probably more important than the additional drag (if you're at reasonable speeds).

Also, an 'advantage' of the R1 is that its cross sectional area is quite large, so it hides more of the trailer compared to a MY.

Bottom line is that I would expect less than 50% range reduction if the trailer isn't super heavy (like that 9000 lbs beast that was mentioned) or bulky.

Most people are towing their trailer primarily at highway speeds. Even if you're staying below 60, that is still a lot of wind resistance.

The R1T is very much optimized to minimize wind resistance. The typical camper trailer is very much not. They usually have only a tiny bit of consideration given to reducing wind resistance, and they are also usually taller than a full size pickup truck and designed under the assumption that the full size pickup will give it a bit of a draft.

I think towing a big trailer at city street speeds would be enormously more efficient than highway speeds, since wind resistance really is the dominant factor. It's just that nobody really tows that way (typically speaking, there are exceptions like coastal roads).

 

[sciencegeek]

Yeah I hear you about drag, but weight is a huge factor and in the absence of actual numbers for your specific setup it's probably useless to speculate. I just think that a modest setup at modest (highway) speeds will not set you back 50%.

 

[LoudMusic]

Most people are towing their trailer primarily at highway speeds. Even if you're staying below 60, that is still a lot of wind resistance.

The R1T is very much optimized to minimize wind resistance. The typical camper trailer is very much not. They usually have only a tiny bit of consideration given to reducing wind resistance, and they are also usually taller than a full size pickup truck and designed under the assumption that the full size pickup will give it a bit of a draft.

I think towing a big trailer at city street speeds would be enormously more efficient than highway speeds, since wind resistance really is the dominant factor. It's just that nobody really tows that way (typically speaking, there are exceptions like coastal roads).

That's a good point and really changes the calculations on long routes. Maybe it will be better to take a US or state highway instead of the interstate, and keep speeds down to 55mph instead of blazing along the interstate at 80mph. The range will go up and you'll spend less time at chargers. And besides, the scenery is better.

 

[ipadl]

Yoss,

My family and I just finished a trip from Kalispell, MT to Jasper, AB with our R1T. We had 5 bikes over the bed and we were pulling a 27' Keystone Passport camper. The overall trip was 1300 miles and speed (wind resistance) was the largest factor. Case in point - the longest leg without charging was 132 miles and 6700' of elevation gain. I was able to squeak out 1.16 mi/kwh through very conservative driving.

In preparation for the trip I did a lot of tow testing with a variety of trailers at various highway speeds. I found that on a 62 mile loop with roughly 680 feet of elevation gain I saw the following efficiencies:
1. R1T in conserve - 2.69mi/kwh @ 51mph avg*
2. R1T in towing w/ flatbed trailer weighed down to ~5000# - 1.48mi/kwh @ 45mph avg*
3. R1T in towing w/ Keystone camper (approx 5500#) - .92mi/kwh @ 48mph avg*
4. R1T in towing w/ empty cargo (probably 3500#) - 1.06mi/kwh @ 47mph avg*

As is noted all over on the Internet wind resistance is the largest consideration as drag increases (if nothing else changes) as a function of the square of your speed. This is why trains are so efficient. Once they get their load up to speed the energy required to keep it moving is less.

The final tow test that I did pre-trip was to drive a 126mi route with 4400' of elevation gain (and loss) as an out and back. I got the following results:
1. 1.11mi/kwh @ 44mph avg - Cruise Control set at 55mph*
2. 1.15mi/kwh @ 44mph avg - "hypermiling" by speeding up going down hills and slowing down going back up hills**

This gave me the confidence that I could make an appreciable improvement in my efficiency by constant throttle rather than constant speed.

592wh/mi is equivalent to 1.7mi/kwh. I achieved this efficiency with a motorcycle on a hitch rack and pulling a lightweight (1500#?) trailer with a raft on it for ~140 miles. My average speed was 46mph (but this likely included loading and unloading the raft, so actual driving speed was much higher).

If you are okay with driving slowly (targetting 55mph give or take) I think 1.7 mi/kwh may be achievable depending on the cross section of the teardrop. If it's a shorter teardrop this seems within reach. If it's taller you will certainly see better numbers than I saw on our trip (up to 1.2 mi/kwh) but may not get to the full 1.7.

I hope this helps. If you have more specific questions let me know. I would love to pull more trailers on my course to get additional data. I am trying to line up an airstream so I can compare it apples to apples against my Keystone at the same speeds. I'd really like to understand if their shape makes that much difference...

Notes:
*These tests were done using the 22" Rivian wheels and Scorpion Zero tires
**This result came with new 20" American Racing wheels and Scorpion AT tires AND 5 bikes over the bed of the truck.

Seth

 

[LoudMusic]

Yoss,

My family and I just finished a trip from Kalispell, MT to Jasper, AB with our R1T. We had 5 bikes over the bed and we were pulling a 27' Keystone Passport camper. The overall trip was 1300 miles and speed (wind resistance) was the largest factor. Case in point - the longest leg without charging was 132 miles and 6700' of elevation gain. I was able to squeak out 1.16 mi/kwh through very conservative driving.

In preparation for the trip I did a lot of tow testing with a variety of trailers at various highway speeds. I found that on a 62 mile loop with roughly 680 feet of elevation gain I saw the following efficiencies:
1. R1T in conserve - 2.69mi/kwh @ 51mph avg*
2. R1T in towing w/ flatbed trailer weighed down to ~5000# - 1.48mi/kwh @ 45mph avg*
3. R1T in towing w/ Keystone camper (approx 5500#) - .92mi/kwh @ 48mph avg*
4. R1T in towing w/ empty cargo (probably 3500#) - 1.06mi/kwh @ 47mph avg*

As is noted all over on the Internet wind resistance is the largest consideration as drag increases (if nothing else changes) as a function of the square of your speed. This is why trains are so efficient. Once they get their load up to speed the energy required to keep it moving is less.

The final tow test that I did pre-trip was to drive a 126mi route with 4400' of elevation gain (and loss) as an out and back. I got the following results:
1. 1.11mi/kwh @ 44mph avg - Cruise Control set at 55mph*
2. 1.15mi/kwh @ 44mph avg - "hypermiling" by speeding up going down hills and slowing down going back up hills**

This gave me the confidence that I could make an appreciable improvement in my efficiency by constant throttle rather than constant speed.

592wh/mi is equivalent to 1.7mi/kwh. I achieved this efficiency with a motorcycle on a hitch rack and pulling a lightweight (1500#?) trailer with a raft on it for ~140 miles. My average speed was 46mph (but this likely included loading and unloading the raft, so actual driving speed was much higher).

If you are okay with driving slowly (targetting 55mph give or take) I think 1.7 mi/kwh may be achievable depending on the cross section of the teardrop. If it's a shorter teardrop this seems within reach. If it's taller you will certainly see better numbers than I saw on our trip (up to 1.2 mi/kwh) but may not get to the full 1.7.

I hope this helps. If you have more specific questions let me know. I would love to pull more trailers on my course to get additional data. I am trying to line up an airstream so I can compare it apples to apples against my Keystone at the same speeds. I'd really like to understand if their shape makes that much difference...

Notes:
*These tests were done using the 22" Rivian wheels and Scorpion Zero tires
**This result came with new 20" American Racing wheels and Scorpion AT tires AND 5 bikes over the bed of the truck.

Seth

Do you have pictures of the rig as you described it here? I suspect putting the bikes inside the trailer would have been a HUGE improvement to consumption.

 

[ipadl]

Pictures are in my post. The bikes may make a difference but my guess is that it's small in comparison to the wall that is the camper but you never know. It would be interesting to church out.

Putting the 5 bikes in the camper with the slideout closed is not possible. Better to install a hitch mount on the trailer but, again, I think the numbers I have been looking at show a small impact in relation to the trailer itself.

 

[Yossarian]

Yoss,

My family and I just finished a trip from Kalispell, MT to Jasper, AB with our R1T. We had 5 bikes over the bed and we were pulling a 27' Keystone Passport camper. The overall trip was 1300 miles and speed (wind resistance) was the largest factor. Case in point - the longest leg without charging was 132 miles and 6700' of elevation gain. I was able to squeak out 1.16 mi/kwh through very conservative driving.

In preparation for the trip I did a lot of tow testing with a variety of trailers at various highway speeds. I found that on a 62 mile loop with roughly 680 feet of elevation gain I saw the following efficiencies:
1. R1T in conserve - 2.69mi/kwh @ 51mph avg*
2. R1T in towing w/ flatbed trailer weighed down to ~5000# - 1.48mi/kwh @ 45mph avg*
3. R1T in towing w/ Keystone camper (approx 5500#) - .92mi/kwh @ 48mph avg*
4. R1T in towing w/ empty cargo (probably 3500#) - 1.06mi/kwh @ 47mph avg*

As is noted all over on the Internet wind resistance is the largest consideration as drag increases (if nothing else changes) as a function of the square of your speed. This is why trains are so efficient. Once they get their load up to speed the energy required to keep it moving is less.

The final tow test that I did pre-trip was to drive a 126mi route with 4400' of elevation gain (and loss) as an out and back. I got the following results:
1. 1.11mi/kwh @ 44mph avg - Cruise Control set at 55mph*
2. 1.15mi/kwh @ 44mph avg - "hypermiling" by speeding up going down hills and slowing down going back up hills**

This gave me the confidence that I could make an appreciable improvement in my efficiency by constant throttle rather than constant speed.

592wh/mi is equivalent to 1.7mi/kwh. I achieved this efficiency with a motorcycle on a hitch rack and pulling a lightweight (1500#?) trailer with a raft on it for ~140 miles. My average speed was 46mph (but this likely included loading and unloading the raft, so actual driving speed was much higher).

If you are okay with driving slowly (targetting 55mph give or take) I think 1.7 mi/kwh may be achievable depending on the cross section of the teardrop. If it's a shorter teardrop this seems within reach. If it's taller you will certainly see better numbers than I saw on our trip (up to 1.2 mi/kwh) but may not get to the full 1.7.

I hope this helps. If you have more specific questions let me know. I would love to pull more trailers on my course to get additional data. I am trying to line up an airstream so I can compare it apples to apples against my Keystone at the same speeds. I'd really like to understand if their shape makes that much difference...

Notes:
*These tests were done using the 22" Rivian wheels and Scorpion Zero tires
**This result came with new 20" American Racing wheels and Scorpion AT tires AND 5 bikes over the bed of the truck.

Seth

Thanks much @ipadl - the info is welcome and helpful.

 

[LoudMusic]

Pictures are in my post. The bikes may make a difference but my guess is that it's small in comparison to the wall that is the camper but you never know. It would be interesting to church out.

Putting the 5 bikes in the camper with the slideout closed is not possible. Better to install a hitch mount on the trailer but, again, I think the numbers I have been looking at show a small impact in relation to the trailer itself.

I completely missed the bikes on first view - phone screen is too small

I feel like I read somewhere that bikes on top of Teslas or even on hitch post style racks have a rather large impact on range. Something like 10 to 15 %.It's definitely worth some trial runs.

 

[ipadl]

I've heard that also. I've tried to limit the number of variables in my testing but this is certainly an area that could warrant some more investigation. I'll try to find time to run a few more routes to see if I can identify any discernable differences.