[ipadl]

Hey all,

Like many of you I'm interested in understanding the range impact of towing trailers. Personally, I have several that I'd like to tow - everything from a small trailer with a 14' NRS raft to a 27' travel trailer. I have access to many different types of trailers for testing and this morning I logged a control drive on one of two routes for testing.

The first route is a flat 62mi loop that we use for testing our specialty vehicles (at work). This route has 679' of elevation gain.

The second route is 95 miles total with about 2500' of elevation gain. The majority of the climbing is in the first 1/2 (it's an out and back) so I should be able to make it home if it starts consuming more than I'm anticipating.

I ran the first route this morning driving the speed limit as a control in Conserve mode. I'm going to repeat the test in towing mode (no trailer, however). I know that you can tow in conserve mode (because I tried it) but I'm admittedly unsure of the differences between tow mode and conserve mode (I'm assuming 4wd vs 2wd at minimum). I'm hoping that this gives me a comparison of the energy used just by switching from conserve to tow mode. While I'd love to run these tests in triplicate, I'm just not sure I have time to drive these routes that many times.

I AM planning to run these courses in both conserve and towing modes in the following configurations:

1. Unladen (control)
2. Pulling a flatbed with ~5-6000# weight (to match the weight of the travel trailer below)
3. Pulling a 27' ~5-6000# travel trailer
4. Pulling a flatbed with raft and motorcycle rack (much lighter and middle of the road on wind resistance).

I'm going to keep track of energy usage, external temperature, tire pressure, beginning and ending SoC, Avg speed, efficiency and will perform the tests without HVAC running. I'm planning on setting cruise at the speed limit. If time (and interest) allows I may repeat some of these tests at different speeds above/below the speed limit to see how the efficiency in impact by 5mph variance.

What other things would people like to see tested? I'm not making any promises, but I would be curious to hear other ideas out there as I get some testing on this truck.

Seth

 

[camaroz1985]

Thanks for spending your time to help everyone still waiting. Interested to see your results.

 

[archiboy]

This would be huge for me. If you are in NorCAL PM me. I might be interested in helping. I've got an R1T with 22" wheels and similar to you - I've got lots of different trailers I'm looking to utilize. Typically I'm doing a 10 hour run between the SF Bay Area and the Oregon Coast. Having predictive data would be huge.

 

[ipadl]

I'll put more detail in future posts on this topic but here's a little towing update for consideration. I've now run our first loop four times with our R1T - 1x unladen in Conserve mode, 1x unladen in towing mode, 1x pulling a 5500# travel trailer in Conserve mode and 1x pulling the same trailer in towing mode.

Unladen I drove the posted speed limit with a maximum of 70mph and the roads were a mix of 2 and 4 lane highways. Pulling the trailer I drove the speed limit but reduced the sections of 70mph to 65mph. The loop is 62 miles long and has 680 feet of elevation gain/loss.

Unladen in Conserve:
1. SoC: 79% starting, 60% ending
2. Avg speed: 51mph
3. Duration: 73 min
4. Efficiency: 2.69 mi/kWh
5. Total Energy: 23 kWh
6. Tire pressure - 50psi (all within 1 psi)

Unladen in Towing:
1. SoC: 59% starting, 37% ending
2. Avg speed: 49mph
3. Duration: 76 min
4. Efficiency: 2.38 mi/kWh
5. Total Energy: 26 kWh
6. Tire pressure - 50psi (all within 1 psi)

Travel Trailer in Conserve:
1. SoC: 78% starting, 26% ending
2. Avg speed: 49mph
3. Duration: 77 min
4. Efficiency: 0.98 mi/kWh
5. Total Energy: 63 kWh
6. Tire pressure - 50psi (all within 1 psi)

Travel Trailer in Towing:
1. SoC: 68% starting, 14% ending
2. Avg speed: 48mph
3. Duration: 77 min
4. Efficiency: 0.92 mi/kWh
5. Total Energy: 67 kWh
6. Tire pressure - 50psi (all within 1 psi)

 

[Wing]

Do the trailer brakes work in conserve mode?

 

[ipadl]

That's a great question. I don't have anything definitive from Rivian. There is no manual brake button in Conserve mode so it's really hard to gauge from just driving. I'll see if it's obvious from just pushing on the brake with somebody watching/listening at the trailer.

 

[Wing]

Can you adjust the brake strength in tow mode? I think you roll the wheel? Thought someone mentioned that

 

[ipadl]

Can you adjust the brake strength in tow mode? I think you roll the wheel? Thought someone mentioned that

Yes. In tow mode you have the option to adjust the brake strength.

 

[ipadl]

Two more general observations about towing with the R1T:

1. The mirrors are terrible for towing wide trailers - you just can't see very much. I'm probably spoiled by using Ford's towing mirrors for the past several years. I'll be looking for a set of add ons or some way to gain more fish eye. Suggestions are welcome!
2. The rear camera is at a terrible location/angle for attaching a trailer. I've had to resort to running back to check or getting somebody to help.
3. The automatic brake "Hold" when not moving requires quite a bit of accelerator input to get out of - Because of 2., above, I feel like I'm going to slam into my trailer when making small adjustments to get hooked up. It occurred to me that this might be better in "Towing" mode. I tried it once this weekend and it seemed better, but I'll want to try them back to back to see if I can tell if there is much of a difference.
4. I'm bad at counting.

 

[ipadl]

This weekend I drove from Kalispell, MT to Tally Lake Campground with our travel trailer and some bikes to test things out. After experiencing roughly 1% battery usage for every 1 mi driven in some of the tests, above, I was a little worried about taking the R1T very far off the beaten path when electrical hookups were unavailable. I had an initial parasitic load test (only 12 hours) that suggested I should see about 2% for every 12 hours of not doing anything. The goal this weekend was to get a better idea of range impact and parasitic load.

(don't mind the gouges in the lawn)

Route: Home in Kalispell, MT to Tally Lake Campground
Distance: 25 miles
Elevation gain: 694'
Elevation loss: 614'
Speed: 50-55 paved, 25-35 gravel
Load: 5500# camper, ~40 gal fresh water, 3 bikes on roof and 2 bikes in bed, 3 kids and my wife
Drive mode: towing
Starting SoC: 91%
Estimated ending SoC: 66%
Actual ending SoC: 77%
Efficiency: 1.24mi/kWh
Total Energy: 20kWh

5/27 pm notes:

• Turned off Wi-Fi, Bluetooth and HVAC
• Tried not to go in/out of the truck much and lock immediately afterward
• 77% SoC @ 8:45pm

5/28 am notes:
- 75% SoC @ 9:15am
Estimated overnight % loss: 2%
Actual overnight loss: 2%
- Lost 2% in ~12.5 hours

5/28 pm notes:
- 73% SoC @ 8pm
Estimated daily % loss: 2%
Actual daily % loss: 2%
- Lost 2% in ~10.75 hours

5/29 am notes:
- 70% SoC @ 8:45am
Estimated overnight % loss: 2%
Actual overnight % loss: 3%
- Lost 3% in ~12.75 hours

Dumping Note:
- I drove through the campground to dump before heading home on 5/29. This, and a bit more parasitic load probably accounted for another 1% battery usage.

Route: Tally Lake Campground to car wash in Kalispell, MT to home
Distance: 28.5 miles
Elevation gain: 614'
Elevation loss: 694'
Speed: same
Load: same
Drive mode: towing
Starting SoC: 69%
Estimated ending SoC: 44%
Actual ending SoC: 49% (didn't actually get a picture of this, so this may be incorrect, but I think I saw 49%)
Efficiency: 1.24mi/kWh
Total Energy: 23kWh

Final notes:

• The R1T used less power than I was expecting by quite a bit. Speed/aerodynamics seems to make the biggest difference in range. At 1.24mi/kWh I should be able to get somewhere closer to 155 miles of total range at 55mph. That said, I'm not sure I'd ever push it that far with serious pucker factor.
• I didn't power the camper at all from the Rivian because I wanted a good data set. That said, I have another trip coming up in two weeks where I'll be going a little further (44 miles each direction) and I may run the camper a little bit off of the Rivian.

 

[sciencegeek]

Oh nice, Tally Lake!! Great data, thanks for sharing. I don't / won't tow so this is a parenthetical comment: that parasitic drain is insane. They have to do something about that.

 

[ipadl]

It has been a while since I've posted much of my towing results. I run an R&D department for a specialty vehicle manufacturer and I've been putting a bunch of towing miles (primarily over bumpy roads) testing some new interior ceiling and exterior storage box designs. At some point I'm going to try to summarize my findings but for now, I'll do two posts about two different trips.

I have a Canada trip with the family in August and there is one leg that is a bit concerning. Specifically, it is 144 miles between chargers with approximately 7000' of elevation gain. To get an idea of range my 8yo daughter and I set out on a long(er) slow trip from Kalispell, MT to Pablo, MT and back on 6/12. Here are the stats: The total trip was 125.9 miles and, according to Google Maps, included 4340' of elevation gain. Here are the stats:

Route: Home in Kalispell, MT to Pablo, MT and back
Distance: 125.9 miles
Elevation gain: 4340'
Elevation loss: 4340'
Speed: 44 mph (tried to keep cruise control no higher than 55 mph)
Load: 5500# camper, ~40 gal fresh water, roof rack with 2x bike racks and 1x kayak rack (not pictured)
Drive mode: towing
Starting SoC: 100%
Actual ending SoC: 9%
Efficiency: 1.11 mi/kWh
Total Energy: 113 kWh

Extrapolating these results (only one data point I realize...) gives me 138.5 theoretical miles if I'm able to use all 100%. To get the remaining 5.5 miles I would need to increase my efficiency to 1.15 mi/kWh. I also need to consider that I will need to climb an additional 3650' and I'd like to keep an extra 10ish miles in the pack. With that in mind I am guessing that I would need to drive around 45mph (ABRP says 40mph) to make it.

I'm intrigued by the idea of bringing extra batteries (and a big inverter) with us and if we have the parts on hand to do this (we are now manufacturing our own battery packs) I may do this. it's a little extra weight but would provide a good deal of peace of mind for this leg!

 

[Wing]

Sounds stressful.

Also cruise is the worse for economy you are better off to anticipate, accelerate down hills and coast up the hills

 

[ipadl]

Sounds stressful.

Also cruise is the worse for economy you are better off to anticipate, accelerate down hills and coast up the hills

Agreed. Although my "backup" plan would be to simply drop the trailer close to the destination - go get a quick bump charge, then return to grab the trailer. Might be easy said than done, but I would guess that it's an option at the least.

I do think I could eek out a few more miles with better driving strategies (like the one you are describing). If I can find a little more time I'm going to try to create a course much more like (or ideally even more strenuous than) the Canada leg. I'll vary speed more to see what kind of results I can expect.

 

[ipadl]

Next data set was from rafting yesterday. This is another configuration that I've been curious about - trying to determine how much range I can expect when pulling my raft and motorcycle. In general, the rivers that we are rafting on are less than 100 miles round trip. Yesterday, however, we drove about 140 round trip. This is just slightly shorter than if we were going to run up and float on the North Fork of the Flathead River from the Canadian Border south to Columbia Falls area. Here are the stats:

Route: Home in Kalispell, MT to Bear Creek put in near Essex, MT and back
Distance: 140 miles
Elevation gain: 3205'
Elevation loss: 3205'
Speed: 46 mph (only used cruise control on the flats - otherwise tried to drive "smarter")
Load: Dual Sport motorcycle and rack, raft trailer, and 14' raft.
Starting SoC: 85%
Actual ending SoC: 17%
Efficiency: 1.71 mi/kWh
Total Energy: 82 kWh

If you extrapolate this out it looks like I could have travelled 206mi if I would have charged to 100% and drained to 0%. This is not a great real world example as you'd likely need to find a charger before you hit 0%, but appears to be theoretically possible. No question that I could have gotten even greater range with slowing down a little bit.

General Note: I realize that for all of these tests my "Speed" looks really slow. There is a fair amount of slowing down to go through towns that takes place. In the case above we stopped twice for food - once for lunch and another for dinner and there is no doubt that the time spent driving 25mph made an impact. Even on highway routes I'm amazed at how much lower the average speed is than what I would say if I would have given my gut. Or, in summary, I wasn't setting my cruise at 46mph for this test (and same for the others).

 

[Wing]

Your camper experience makes me happy. I tow a 9ft tall 20ft long car hauler. Probably about 6500lbs loaded. Car is 2300 so I'm just guessing.

I need about 90 miles for my trip to the race track and back. Sounds like i should be able to do this no problem.

Currently lx570 takes me 40L so 10gallons of fuel to do the same trip.

 

[ipadl]

Your camper experience makes me happy. I tow a 9ft tall 20ft long car hauler. Probably about 6500lbs loaded. Car is 2300 so I'm just guessing.

I need about 90 miles for my trip to the race track and back. Sounds like i should be able to do this no problem.

Currently lx570 takes me 40L so 10gallons of fuel to do the same trip.

I'm glad that it's helpful data! When towing my 5500# camper unloaded at 65mph on a fairly flat course I was seeing ~.92 mi/kWh. I think 100 mi with your setup will be very doable.

 

[Wing]

Yeah half the trip is at 55mph the other half 65 so average of 60.

On return usually book it back at 80 though lol.

 

[syn.mlbrown]

Hey all,

Like many of you I'm interested in understanding the range impact of towing trailers. Personally, I have several that I'd like to tow - everything from a small trailer with a 14' NRS raft to a 27' travel trailer. I have access to many different types of trailers for testing and this morning I logged a control drive on one of two routes for testing.

The first route is a flat 62mi loop that we use for testing our specialty vehicles (at work). This route has 679' of elevation gain.

The second route is 95 miles total with about 2500' of elevation gain. The majority of the climbing is in the first 1/2 (it's an out and back) so I should be able to make it home if it starts consuming more than I'm anticipating.

I ran the first route this morning driving the speed limit as a control in Conserve mode. I'm going to repeat the test in towing mode (no trailer, however). I know that you can tow in conserve mode (because I tried it) but I'm admittedly unsure of the differences between tow mode and conserve mode (I'm assuming 4wd vs 2wd at minimum). I'm hoping that this gives me a comparison of the energy used just by switching from conserve to tow mode. While I'd love to run these tests in triplicate, I'm just not sure I have time to drive these routes that many times.

I AM planning to run these courses in both conserve and towing modes in the following configurations:

1. Unladen (control)
2. Pulling a flatbed with ~5-6000# weight (to match the weight of the travel trailer below)
3. Pulling a 27' ~5-6000# travel trailer
4. Pulling a flatbed with raft and motorcycle rack (much lighter and middle of the road on wind resistance).

I'm going to keep track of energy usage, external temperature, tire pressure, beginning and ending SoC, Avg speed, efficiency and will perform the tests without HVAC running. I'm planning on setting cruise at the speed limit. If time (and interest) allows I may repeat some of these tests at different speeds above/below the speed limit to see how the efficiency in impact by 5mph variance.

What other things would people like to see tested? I'm not making any promises, but I would be curious to hear other ideas out there as I get some testing on this truck.

Seth

Would love to see some results with a roof top tent in both locations.