Towing Airstream Classic

azbill

Well-Known Member
First Name
Bill
Joined
Jun 8, 2020
Messages
76
Reaction score
33
Location
Arizona
First Name
Bill
Vehicles
GMC Sierra, Bolt, Sky
Occupation
Engineer
I have three trailers, (boat, horse, flatbed) all in the range of 5000-7000 lbs. I only use those within about 50 miles of my home, so even a hit of 50% range is no big deal. But if I were taking longer trips with a travel trailer, I would worry about the hassle of having to unhitch and re-hitch the trailer each time I needed a fast charge. The vast majority of chargers are in parking lots without any room for a trailer. If you look at the Tesla Superchargers, everyone backs in to the stations, so the trailer has to be unhitched.

Also related to this, does anyone know if they will have charging ports on both sides of the truck? All of the higher KW new DC fast chargers also have very short cables, which makes it more of a hassle to park the right direction, depending on which charger is available (or in some cases ICE vehicles in the way).
 

electruck

Well-Known Member
Joined
Oct 6, 2019
Messages
473
Reaction score
456
Location
Dallas, TX
Vehicles
2018 Volvo XC60
Can't recall where but I've also seen mention of pull-through charging stations for those that are towing. With Model X and others such as Rivian on the horizon capable of towing, we'll definitely need to have those around. I can see where they wouldn't have been included in early phases of charger network build out but it's something that needs to be addressed in the next 12-18 months.
 

ElectricTrucking

Well-Known Member
Joined
Dec 23, 2018
Messages
230
Reaction score
126
Location
Cave Creek AZ
Vehicles
Porsche 911
Fast Lane Truck on YouTube did an extensive study on towing with A model X but they used tesla Chargers to see about difficulty with charging while towing. At times they had to disconect. I don't think any charging was Electrify America.
 
OP
S

steilkurve

Member
First Name
Nic
Joined
May 11, 2020
Messages
8
Reaction score
2
Location
Montreal, Canada
First Name
Nic
Vehicles
2017 Tesla Model X 100D, 2018 Model 3 Performance, 2020 Airstream Bambi 22FB
  • Thread starter
  • Thread Starter
  • #20
I’ve had to unhitch to charge my X while towing our current 22’ AS a few times. I’ve also been lucky and visited empty SuperChargers where I pulled up sideways and did not have to unhitch (stayed by the rig to move it if needed of course). Mostly though, we charge at the camp site. Even those with only 15 amps give me what I need for the next leg if staying for a few days. In rare cases, once set up at our camp site, we travel with the X to a nearby charging station and try to marry that with sightseeing, eating out or grocery shopping. Mostly happens when we need the AC in the Airstream which does not run off the trailer‘s batteries. Takes some planning but totally doable.

What will make or brake Rivian as a towing vehicle IMO is their charging infrastructure. You need easy and prevalent charging options for this to work. Even though I charge at campgrounds a lot, you do need to charge up on the road from time to time and you can’t be hunting for charging stalls that few and far between.
 

azbill

Well-Known Member
First Name
Bill
Joined
Jun 8, 2020
Messages
76
Reaction score
33
Location
Arizona
First Name
Bill
Vehicles
GMC Sierra, Bolt, Sky
Occupation
Engineer
I’ve had to unhitch to charge my X while towing our current 22’ AS a few times. I’ve also been lucky and visited empty SuperChargers where I pulled up sideways and did not have to unhitch (stayed by the rig to move it if needed of course). Mostly though, we charge at the camp site. Even those with only 15 amps give me what I need for the next leg if staying for a few days. In rare cases, once set up at our camp site, we travel with the X to a nearby charging station and try to marry that with sightseeing, eating out or grocery shopping. Mostly happens when we need the AC in the Airstream which does not run off the trailer‘s batteries. Takes some planning but totally doable.

What will make or brake Rivian as a towing vehicle IMO is their charging infrastructure. You need easy and prevalent charging options for this to work. Even though I charge at campgrounds a lot, you do need to charge up on the road from time to time and you can’t be hunting for charging stalls that few and far between.
Unfortunately a vast majority of EA chargers are not set up like the Tesla Super Chargers, they have most of them with two stations with angle parking on each side. There are a few where they are all in a row, but not very many, and even those tend to be in crowded parking lots. Then if you block them and a car comes in to charge, you need to be kind and get out of the way, as you stated.

I have seen pictures of proposed stations where they are more like gas stations, but I doubt these will be widely available for at least ten years or more. Look how long it has taken EA to build out the current infrastructure, it is still far from complete.

I did see a picture of some new proposed Tesla Super Chargers that were set up as drive through ones for Quartzsite Arizona. I think they plan on replacing the existing ones there.
 

CappyJax

Well-Known Member
Joined
Dec 26, 2018
Messages
288
Reaction score
106
Vehicles
Subaru Forester
I really hope Rivian includes a 30 amp plug for powering RV's. Although I am building a system on my RV that won't require that much amperage since I am installing four Tesla modules and an inverter. I should be able to run the AC for 10 hours straight with no sun available. With sun, I should get about 15 hours. But, I plan to charge it on the go with a 24V alternator. The Rivian won't provide that option, so it will have to be solar to charge it, or at a park. Or lower amperage from the Rivian 120 outlets. But the whole idea is to avoid the parks to save money.

I must say that the technology for travel trailers is lagging a great deal. We should have all electric, regenerative braking, large solar panel systems, etc. etc.
 
OP
S

steilkurve

Member
First Name
Nic
Joined
May 11, 2020
Messages
8
Reaction score
2
Location
Montreal, Canada
First Name
Nic
Vehicles
2017 Tesla Model X 100D, 2018 Model 3 Performance, 2020 Airstream Bambi 22FB
  • Thread starter
  • Thread Starter
  • #23
Unfortunately a vast majority of EA chargers are not set up like the Tesla Super Chargers, they have most of them with two stations with angle parking on each side. There are a few where they are all in a row, but not very many, and even those tend to be in crowded parking lots. Then if you block them and a car comes in to charge, you need to be kind and get out of the way, as you stated.

I have seen pictures of proposed stations where they are more like gas stations, but I doubt these will be widely available for at least ten years or more. Look how long it has taken EA to build out the current infrastructure, it is still far from complete.

I did see a picture of some new proposed Tesla Super Chargers that were set up as drive through ones for Quartzsite Arizona. I think they plan on replacing the existing ones there.
There are a few Tesla SuperChargers that are pull through. Nearly not enough but they exist.
 
OP
S

steilkurve

Member
First Name
Nic
Joined
May 11, 2020
Messages
8
Reaction score
2
Location
Montreal, Canada
First Name
Nic
Vehicles
2017 Tesla Model X 100D, 2018 Model 3 Performance, 2020 Airstream Bambi 22FB
  • Thread starter
  • Thread Starter
  • #24
I really hope Rivian includes a 30 amp plug for powering RV's. Although I am building a system on my RV that won't require that much amperage since I am installing four Tesla modules and an inverter. I should be able to run the AC for 10 hours straight with no sun available. With sun, I should get about 15 hours. But, I plan to charge it on the go with a 24V alternator. The Rivian won't provide that option, so it will have to be solar to charge it, or at a park. Or lower amperage from the Rivian 120 outlets. But the whole idea is to avoid the parks to save money.

I must say that the technology for travel trailers is lagging a great deal. We should have all electric, regenerative braking, large solar panel systems, etc. etc.
I agree. Solar is optional on most and included batteries are anemic. Could be much better.
 

CappyJax

Well-Known Member
Joined
Dec 26, 2018
Messages
288
Reaction score
106
Vehicles
Subaru Forester
I agree. Solar is optional on most and included batteries are anemic. Could be much better.
Yeah, I am going to have 800W of solar, and I think I can squeeze in another 2 100W panels. But if they laid out the roof with some consideration for solar, I could probably have 1800W easily.

And yeah, installed batteries are 1.2kWh of useable energy. That might last one cold night of running the furnace if I am lucky. 16kWh with 800W of solar should insure I can stay out as long as I have propane. Probably 3 weeks.
 

irwinr

New Member
First Name
Jeremy
Joined
Aug 3, 2020
Messages
1
Reaction score
1
Location
Austin, TX
First Name
Jeremy
Vehicles
Nissan LEAF, Chevy 2500HD Duramax, Jeep Liberty
Occupation
Software Consulting
I know I'm late to reply to this, but thought I'd share some real world metrics I've gathered from pulling lots of various trailers with my truck.

I have a 2007.0 Duramax 2500HD (LBZ engine). Over the years I've owned several different travel trailers, all of which pulled by the same truck. One issue with this model of Duramax is it has a tiny 26 gal fuel tank, and it would only really let you use 20 gallons before the "low fuel" lights and bells/buzzers would start going off like crazy. Thus my towing range was greatly limited by my MPG and so I tracked my MPG very very closely:
  • 4,000lb 19ft travel trailer
    • 10-12 MPG avg
  • 5,000lb 27 ft travel trailer
    • 9-11 MPG avg
  • 7,500lb 31 ft "Bullet" travel trailer
    • 10-12 MPG avg
    • Bullet had a slightly more aerodyamic shape, but not by much
  • 9,500lb 31ft travel trailer
    • 9-11 MPG avg
But I can tow my 8,000lb flatbed trailer with a car on it and get 15 MPG.

As you can see: The weight and length of the trailer has very little impact on towing efficiency. The biggest impact is aero: And almost all travel trailers have the same aerodynamic profile: A big flat front and a big flat back (And lots of random things hanging off the roof, sides, and bottom). My bullet trailer I mentioned had a slightly more aerodynamic fiberglass front cap, and the roof was a bit more curved a the sides, but the sides and back were still quite square so the difference in MPG, while noticeable, was not huge.

Also: I generally achieved my highest MPGs driving in the mountains which surprises most people. I believe that's because even in an ICE vehicle when you're climbing a hill you're burning a lot more energy on the uphill leg and you "re-coup" some of that that energy on the way down: IE: You burn more fuel going up, but you burn zero fuel going down. Unfortunately a diesel pickup can't put fuel back into the tank going downhill like an EV can, but on a fuel injected engine anytime the throttle position is at 0% and the tranny is spinning the crank faster than the pre-set idle speed, the fuel burn drops to 0 because the injectors just shut off and let gravity and the kinetic energy do all the work.

I also never tried to "race" up a hill. My Duramax runs a nice 500 HP tune and I could easily top all but the steepest hills at 70-75 MPH. But I would happily park myself behind the line of slow moving semi's in the right lane and I'd keep my truck in 6th gear and let it lug down to 1,300 RPM all the way up the hills. So I might top a hill at 50 MPH, take my foot off the accelerator and let gravity accelerate me back to the speed limit before engaging the exhaust brake. Going slower up the hill greatly reduced my aero drag (Plus less drag at higher elevations) and then I burned no fuel going down. In trips through the Rocky Mountains I would often get 14 MPG towing a travel trailer.

So weight increases fuel burn during acceleration and hill climbing, but it actually decreases (or even eliminates) fuel burn going down hills. On an EV with regenerative braking: that extra energy burned during acceleration and going uphill is somewhat re-couped during downhill and braking, which makes the weight effect even less significant.

So as long as you drive in a reasonable way the extra weight shouldn't have much impact. It's the frontal area and shape of the trailer that makes the most impact when towing.
 

CappyJax

Well-Known Member
Joined
Dec 26, 2018
Messages
288
Reaction score
106
Vehicles
Subaru Forester
I know I'm late to reply to this, but thought I'd share some real world metrics I've gathered from pulling lots of various trailers with my truck.

I have a 2007.0 Duramax 2500HD (LBZ engine). Over the years I've owned several different travel trailers, all of which pulled by the same truck. One issue with this model of Duramax is it has a tiny 26 gal fuel tank, and it would only really let you use 20 gallons before the "low fuel" lights and bells/buzzers would start going off like crazy. Thus my towing range was greatly limited by my MPG and so I tracked my MPG very very closely:
  • 4,000lb 19ft travel trailer
    • 10-12 MPG avg
  • 5,000lb 27 ft travel trailer
    • 9-11 MPG avg
  • 7,500lb 31 ft "Bullet" travel trailer
    • 10-12 MPG avg
    • Bullet had a slightly more aerodyamic shape, but not by much
  • 9,500lb 31ft travel trailer
    • 9-11 MPG avg
But I can tow my 8,000lb flatbed trailer with a car on it and get 15 MPG.

As you can see: The weight and length of the trailer has very little impact on towing efficiency. The biggest impact is aero: And almost all travel trailers have the same aerodynamic profile: A big flat front and a big flat back (And lots of random things hanging off the roof, sides, and bottom). My bullet trailer I mentioned had a slightly more aerodynamic fiberglass front cap, and the roof was a bit more curved a the sides, but the sides and back were still quite square so the difference in MPG, while noticeable, was not huge.

Also: I generally achieved my highest MPGs driving in the mountains which surprises most people. I believe that's because even in an ICE vehicle when you're climbing a hill you're burning a lot more energy on the uphill leg and you "re-coup" some of that that energy on the way down: IE: You burn more fuel going up, but you burn zero fuel going down. Unfortunately a diesel pickup can't put fuel back into the tank going downhill like an EV can, but on a fuel injected engine anytime the throttle position is at 0% and the tranny is spinning the crank faster than the pre-set idle speed, the fuel burn drops to 0 because the injectors just shut off and let gravity and the kinetic energy do all the work.

I also never tried to "race" up a hill. My Duramax runs a nice 500 HP tune and I could easily top all but the steepest hills at 70-75 MPH. But I would happily park myself behind the line of slow moving semi's in the right lane and I'd keep my truck in 6th gear and let it lug down to 1,300 RPM all the way up the hills. So I might top a hill at 50 MPH, take my foot off the accelerator and let gravity accelerate me back to the speed limit before engaging the exhaust brake. Going slower up the hill greatly reduced my aero drag (Plus less drag at higher elevations) and then I burned no fuel going down. In trips through the Rocky Mountains I would often get 14 MPG towing a travel trailer.

So weight increases fuel burn during acceleration and hill climbing, but it actually decreases (or even eliminates) fuel burn going down hills. On an EV with regenerative braking: that extra energy burned during acceleration and going uphill is somewhat re-couped during downhill and braking, which makes the weight effect even less significant.

So as long as you drive in a reasonable way the extra weight shouldn't have much impact. It's the frontal area and shape of the trailer that makes the most impact when towing.
You get better mileage in the mountains because of reduced air resistance, not because of the hills. You might get a slightly lower BSFC at a higher power setting, but it would be minimal.
 

skyote

Well-Known Member
Joined
Mar 12, 2019
Messages
853
Reaction score
777
Location
Austin, TX
Vehicles
Jeeps & 2500HD Duramax
I have a 2007.0 Duramax 2500HD (LBZ engine)
I had a 2006 w/ LBZ (mild tune), which now belongs to a friend of mine...great truck. I now have a 2015 LML (mild tune), and pull a 36' 12K fifth wheel & average 9-11 mpg towing, 15-17 without.
 

ohmman

Well-Known Member
First Name
Mark
Joined
Aug 22, 2020
Messages
58
Reaction score
112
Location
Sonoma, California
First Name
Mark
Vehicles
2016 Model X 90D, 2014 Model S P85
When I was researching what I could achieve towing my Airstream with my X, I came across some suggestions that the "hit" to a vehicle with an ICE is less than with an EV. That is because internal combustion engines are already relatively inefficient in the comparison (about 40% for the best ICE vs. close to 90% for the best EV). I don't think the math works out to a direct comparison between the two because of this, but I also don't think it is an enormous difference.

The truth is that the only way we'll know is to have some real world evidence. I tried to collect data from Model Xs pulling different trailers, and the comparison I used was 55mph with no wind on flat roads. That seemed the closest comparison to the EPA rating without the camper. Once we start seeing deliveries and people are pulling campers, hopefully we can start a similar thread here.

I agree wholeheartedly with @irwinr above, though, that aero losses are the primary component of drag at speed. However, dual axles vs. single axles makes a difference as does weight when you need to ensure you make it over that next pass and there is no charging on the way up.

Radius edges on campers help a lot (think Airstream) and most modern teardrops are not aerodynamic despite the fact that they "look" aerodynamic. They taper off too quickly. One of the most aerodynamic camper trailers out there is the Bowlus Road Chief. Note the long tapered tail. Of course, one will be paying for it.
 

CappyJax

Well-Known Member
Joined
Dec 26, 2018
Messages
288
Reaction score
106
Vehicles
Subaru Forester
When I was researching what I could achieve towing my Airstream with my X, I came across some suggestions that the "hit" to a vehicle with an ICE is less than with an EV. That is because internal combustion engines are already relatively inefficient in the comparison (about 40% for the best ICE vs. close to 90% for the best EV). I don't think the math works out to a direct comparison between the two because of this, but I also don't think it is an enormous difference.

The truth is that the only way we'll know is to have some real world evidence. I tried to collect data from Model Xs pulling different trailers, and the comparison I used was 55mph with no wind on flat roads. That seemed the closest comparison to the EPA rating without the camper. Once we start seeing deliveries and people are pulling campers, hopefully we can start a similar thread here.

I agree wholeheartedly with @irwinr above, though, that aero losses are the primary component of drag at speed. However, dual axles vs. single axles makes a difference as does weight when you need to ensure you make it over that next pass and there is no charging on the way up.

Radius edges on campers help a lot (think Airstream) and most modern teardrops are not aerodynamic despite the fact that they "look" aerodynamic. They taper off too quickly. One of the most aerodynamic camper trailers out there is the Bowlus Road Chief. Note the long tapered tail. Of course, one will be paying for it.
The reason why an ICE appears to do better when towing is because of the power to maintain combustion. For example, if the vehicle uses 1 gallon per hour at idle, that 1 GPH provide no useful work, but is always required when the vehicle is under power. If you are going 60MPH and using 3 GPH you get 20MPG, but only 2GPH are providing that work. Now, if you start towing such that twice the energy is needed from the engine, you will be using 5GPH at 60MPH. 4GPH for the work, and that 1GPH to maintain combustion. So, even though you double the energy needed from the engine, you are getting 12.5 MPG instead of 10 MPG.
 
Top