Silverado EV towing a 21

[EscapingDan]

I’ve got a Silverado EV reservation and plan to tow probably an Escape with it, unless there’s some deal killer but I’m not finding it. I calculate that it should be good on average with say a 21 for 180 miles between charges, respecting 55-60 mpg/drafting, and the 80%-20% ideal range for charging. Winnebago puts their customers average driving day at 4-5 hours, so that means about 350 miles of four hours of driving with a single 45 minute stop.

Biggest problem would seem to be charging with a trailer as they’re not set up for that, but GM is partnering with Flying J travel centers and EVGo for Ultium brand trailer friendly charging, which is smart given it’s completely unserved. Otherwise there’s tons of charging everywhere for the most part these days. Additionally I can bring my 7kW generator for a quick emergency charge if we get in some situation.

Advantages are

• Regen braking is a dream for trailering
• Silverado is 1500 equivalent tow capacity but due to the weight is more like an HD
• 200 kW of 115/240 VAC power at any time - silently
• Otherwise a nice quiet and comfortable ride

Disadvantage is having to plan more carefully and some restrictions (Canada isn’t set up yet for EV’s.)

Oh and other consideration is GVWR and such. Silverado can pull 10k lbs and haul 1300 lbs so an Escape should be good there. Like I say this is the plan unless for some reason I find it just won’t work, but it looks good. EV’s are basically a done deal, the manufacturers are all on board and with California phasing out selling ICE vehicals, and already being a EV owner, it seems like the right decision.

[Keith3]

You’re biggest issue will be aero drag. Picking an escape 21 will help a lot with that. Keeping an eye on your speed will help even more.

We tend to travel 250-300 miles a day, but may roll that back to 200-250 now that half of us is retired. Good estimate is 50 mph average traveling time. Sometimes it’s less, sometimes more.

I’m excited to see what kind of range you get and how difficult the planning is. I know Tesla has put a lot of work into making their network very easy to use. I hope one of the big three follows that lead. That cybertruck looks like trash.

Please report back as you go through this journey. Even if you decide to change horses.

[EscapingDan]

Originally Posted by Keith3

You’re biggest issue will be aero drag. Picking an escape 21 will help a lot with that. Keeping an eye on your speed will help even more.

Yes exactly! Weight really only matters in acceleration, aero is the main thing. Without seeing hard data I don’t think we can say much about one trailer or another, but GM says that with ICE or EV range is cut by 25%. Real world tests of the Lightning is showing 50% drop at highway speeds with big trailers. Another anecdotal test I’ve watched was of a pop up trailer where the range reduction was basically zero (because it sits in the drafting bubble of the truck). So average of 0%-50% is 25%.

In practice I think the main thing is to keep speed down.

We tend to travel 250-300 miles a day, but may roll that back to 200-250 now that half of us is retired. Good estimate is 50 mph average traveling time. Sometimes it’s less, sometimes more.

Sounds great to me. I’ll be retired in a few years when all this comes together. But isn’t the problem is the highways? Hard to keep 50 on those.

I’m excited to see what kind of range you get and how difficult the planning is. I know Tesla has put a lot of work into making their network very easy to use. I hope one of the big three follows that lead. That cybertruck looks like trash.

All my colleagues have Teslas, I’m not fond of them. The Cybertruck is silly as far as I’m concerned, it will date really quickly. But anyhow on my trips EVGo has worked perfectly. Electrify America is more ubiquitous but I’ve had more downed chargers and other odd issues. It’s well known what a problem this is, I don’t doubt it’ll get sorted.

Please report back as you go through this journey. Even if you decide to change horses.

Will do, thanks for the support I expected nay saying. It would take a lot for me to back off, I swore that we’d never buy another ICE again. And now my state is outlawing new ICE vehicles anyhow, gradually by 2035 (35% new sales must be EV by 2025!) So the writing is on the wall.

Anyhow it will be a while, GM is telling me I won’t be able to pick it up until 2024.

[JeffreyG]

It could work, but you'll really need to be flexible. As someone who just took my Escape from Detroit to Colorado to see my daughter, I have some experience with distance. Here's my thoughts on the details.

Originally Posted by EscapingDan

Winnebago puts their customers average driving day at 4-5 hours, so that means about 350 miles of four hours of driving with a single 45 minute stop.

I don't care how far Winnebago is trying to go in a day. What matters is your distance need. Once I'm retired short days like that might work out just fine. Right now for me, no way. I have to get places and back within the timeframe of time off work. I can't spent five days going somewhere and five days coming back.

But again, if you have no timeline, short days might work. Then again, it will take you forever to cross some fairly boring areas (no offense to Iowa Dave, but it was 102F, sticky, boring, and I could not cross Iowa fast enough).

Biggest problem would seem to be charging with a trailer as they’re not set up for that, but GM is partnering with Flying J travel centers and EVGo for Ultium brand trailer friendly charging, which is smart given it’s completely unserved. Otherwise there’s tons of charging everywhere for the most part these days.

No, there isn't. There's tons of charging in some areas. And just about zero charging in others. One thing about that 350 mile day is you really have to have a charger located very close to the middle of the drive. If there isn't one, it becomes a much slower two-charge day.

You will block traffic and be a nuisance or need to be able to drop the trailer at 99% of existing chargers. Kudos to Flying J, but this problem is not going to be significantly better by 2024.

Additionally I can bring my 7kW generator for a quick emergency charge if we get in some situation.

It will take that generator 40 hours to charge a Silverado EV. That's a lot of gas. If you stop for lunch and fire up the generator, one loud and annoying hour of run time will give you about 1-2% state of charge back into the vehicle.


The Silverado EV you are eyeing has a 200 kWh battery. That's a huge amount of energy.


Speaking of which.......also be careful not to be too optimistic how fast you can recover that 60-80% SOC on the Silverado EV while you eat lunch. You are talking about adding ~130 kWh to the SOC, which a lot of level 3 chargers won't do in less than 90-120 minutes. Level 3 chargers frequently do not hit their theoretical maximums.

Disadvantage is having to plan more carefully and some restrictions (Canada isn’t set up yet for EV’s.)

I think RV tow vehicles will be the last market taken by EVs to be honest. The charging network is not great (especially away from the Interstates).

Last note, you mentioned towing at 55-60 mph. IMO this is not a safe speed of travel on the Interstates, if that is your intention. If you are on a 75 mph limit road in a non-rural area, you will need to be able to go faster.


And for now, the L3 charging networks are all along the interstates.

[Ron in BC]

Originally Posted by JeffreyG

Last note, you mentioned towing at 55-60 mph. IMO this is not a safe speed of travel on the Interstates, if that is your intention. If you are on a 75 mph limit road in a non-rural area, you will need to be able to go faster.

When we first started towing in CA with an out of country license plate I tried to stick to the required 55mph limit. I felt like I had a target on my back with the huge speed differential to other traffic. I now run closer to 65mph, still passed by most traffic but at less of a speed differential.

Regen braking could be a positive but it's highly dependent on you using your brakes. In hilly situations, yes, but there are parts of the country where you can run for a long time without even touching the brakes.

It'll be interesting, long term, to see how the whole EV towing thing works out.

Ron

[Rockhead]

I don’t understand where they get only towing 4 maybe 5 hrs a day. Geeeezzz . We leave on for a trip dawn 30 n go all day till about 5 or 6 in the evening. Being in Texas, it’s a long way to the mountains for us where we like to camp. I’m 63 n love driving but that’s me. Yes I understand everyone drives different. Just don’t care for someone telling me how long I can tow.

[EscapingDan]

Originally Posted by JeffreyG

It could work, but you'll really need to be flexible. …

Yes thanks I know and have thought about all the points you bring up. I’ve had a Bolt EV for five years and am intimately aware of the advantages and issues still with EV driving. For tl/dr’s sake I’ll just mention that the key I think is that I won’t be able to get the truck for two years, will be retiring in three, and when we start out will be keeping it low key with relatively short trips and otherwise basic trips. It won’t be for five or six years until we want to branch out. Point being that infrastructure has been on an exponential curve since I started, in six years I expect equally dramatic change. Also small point - the idea behind the generator or any backup power supply is that all it needs to do is get you to the next charger.

GM isn’t releasing HD trucks until last in 2035. Given that EV semi’s are in development and releasing before too long says that todays battery architecture is sufficient for towing. But it would seem that GM doesn’t see technology developments (specifically energy density/weight/$) until then which seems right. Anyhow in the meantime range will be improving, Ultium batteries in theory can be upgraded with new chemistry (whether they offer that as an option or not), and we can always trade up in five years when they release the 2028 Silverado with 500+ miles range.

At any rate I love EV driving too much to buy another gasser

Originally Posted by Ron in BC

Regen braking could be a positive but it's highly dependent on you using your brakes.

Oh, what I meant by that is that when dealing with grades it’s no stress, no brake heating (not using the brakes) and such. Some guys took some huge load up and down a tortuous Colorado grade in the Lightning and it was a no stress breeze.

[Keith3]

Just to clarify, we don’t limit our speed to 50mph, we tend to drive the speed limit, up to about 70-75 mph.

What I mean is that if we have 250 miles to cover we find it will typically be a 5 hour day of driving, if it 350 miles we plan on 7 hours of driving that day. Sometimes it’s more, sometimes it’s less, but that has been a good rule of thumb for us over the years.

As you get used to your rig on shorter trips you’ll find a top speed that works best for you.

One thing to consider is that a cap on the truck bed may provide a better overall aero profile while towing. I’m sure the cap companies will claim as much, let’s hope they actually test it.

[EscapingDan]

Originally Posted by Keith3

One thing to consider is that a cap on the truck bed may provide a better overall aero profile while towing. I’m sure the cap companies will claim as much, let’s hope they actually test it.

What I’ve been able to find is that a tonneau cover doesn’t help because the laminar flow has already been disrupted. Obviously they went with the Avalanche style wings to minimize that. But they’re showing bed cab covers which could help. Just like with a sailboat longer length gives better aero. Ideally if you had a back cab which sloped gently down, like the back of a Tesla, that would be ideal. But then you’re punching through the air again with the trailer.

The big manufacturers are coming up with (expensive looking) EV friendly trailers, I’m waiting for somebody to come out with one that was actually designed for minimum aero. My Bolt has a drag coefficient of 3.08, Tesla is 2.08. But let’s see what Airstream has to say, since they make the ‘slipperiness’ a marketing point.

Airstream Aero put to the Test

In that blog post they talk about the low pressure region created between the tow vehicle and trailer, my interpretation is they see that as the low hanging fruit. So in that case as they discuss having air deflectors in the back of the truck to guide the airstream from the truck to the trailer is a good approach - much like what is done with big semis and the air deflector on top.

So yeah, imagine a bed cap that rises slowly towards the back until it reaches the height of the trailer - that probably would be ideal and give you standing room at the back of your bed.

On the other hand here’s some credible information from Jarret trucking and work done at Lawrence Livermore. They estimated that 12% fuel economy could be realized. Now this is trucking not recreational trailering, but I’m not sure it’s worth messing with too much if it gives us only 10% or something.

Improving Fuel Economy

[Ron in BC]

Originally Posted by EscapingDan

What I’ve been able to find is that a tonneau cover doesn’t help because the laminar flow has already been disrupted.

From what I've read the air flow goes over the cab and swoops down into the box and hits "the wall" formed by the tailgate. I think a tonneau cover helps but I'd have one even if it didn't.

So in that case as they discuss having air deflectors in the back of the truck to guide the airstream from the truck to the trailer is a good approach - much like what is done with big semis and the air deflector on top.

It's my understanding that air deflectors can work but they also can create a worse situation if not designed properly. Increasing the low pressure area and causing things like the propane cover to levitate.

There's a lot of science in aerodynamics but I sometimes think that's there a bit of black art involved also.

Ron

[JeffreyG]

Originally Posted by Ron in BC

I
There's a lot of science in aerodynamics but I sometimes think that's there a bit of black art involved also.
Ron

These days it's not so much a black art, but you need expertise in computational fluid dynamics and you should have a full scale wind tunnel to validate the results.


I will say that doing CFD 'in your head' does not work. A lot of things that seem good for aero are not, and a lot of details that you might not even see can make or break the drag of a design.



RV manufacturers don't put any effort into aero work for a very lengthy list of reasons.
1) The vast bulk of the RV market is incredibly price sensitive.
2) Doing good aero development work is expensive and requires expensive capital equipment (namely, a wind tunnel).
3) The RV manufacturer cannot control half of the combination. You might be pulling the trailer with a van, a truck, have tonneau, or a cap, or bikes on the roof, or boats.......

[EscapingDan]

Fluid dynamics modeling can be done in MATLAB or the like and air tunnel time can be rented. OEM’s do think kind of thing commonly, can’t make an electrical widget without doing interference testing in a RF chamber. I’ve worked at companies that had them in house which they also rented out.

The EV market is unserved and getting bigger. Airstream and Winnebago get it, look at their EV concepts from this year. The Airstream is really interesting, has a EV battery and motors, it even parks itself. But if they bring them to market they’ll be expensive and heavy, at least until battery tech brings those down.

FWIW I think there’s space in the trailer market for a truly EV friendly trailer that’s light, feature rich and has decent aero.

[Rossue]

Funny you should mention Airstream- just visited a former Escape 21 owner who bought a new Globetrotter 27. First impressions were like walking into a Four Seasons suite. What a bitchin' trailer! Just doesn't fit our boondocking lifestyle

Doubt that puppy is going to be towed by an EV in the next 20 years, however I could be wrong!

[TahoeJoe]

I smell a business opportunity here...what will folks do with their time while waiting for their EV's to charge at the stations? I'm not sure exactly what forms that opportunity will take, but the point is...lots of customers with disposable income spending more time at stations, and also choosing which stations to spend that time at. One idea: more facilities for pets?

[EscapingDan]

Originally Posted by TahoeJoe

I smell a business opportunity here...what will folks do with their time while waiting for their EV's to charge at the stations?

Yeah the sharks are circling that one already. Personally I don’t think they should bother, things are changing so fast. The Silverado supports 350 kW charging which GM says will give 100 miles in 10 minutes. Our old (by today’s standards) Bolt is a poky 60 kW or something, and by the time we get a pee, stretch, and maybe a drink (the stations are always in mall parking lots) and a little catchup on the phone it’s already done with.

Charging speed is a big focus though, it’s getting faster and faster, and also due to physics it greatly slows down at 80% so you rarely go to 100% anyhow.

[uthorns]

As more people get these EVs the charging stations will be full. You won't just drive to it while on a trip and use it, you just might have to wait. I've never been to the west coast but here in Texas or the travels I've been on all across the south if there are charging stations they must be in metropolitan areas. We avoid those as much as possible when RVing.

[bborzell]

Our plan was to have two EVs and no ICE vehicles. One was to be a VW ID.4 and the other the Lightning which would be our 21C tow vehicle. The first real world test I read was done in Colorado through the hills. They pulled a 2,000 lb. trailer. They got +/- 90 miles on a charge with a very lightweight camper. The hills were killers for the lightning. Our experience living in the Sierra foothills and driving a 22 VW ID.4 EV confirms the rapid range reduction as we drive from the valley to home. With a trailer, it would be an even greater reduction.

After reading more, it became apparent to me that towing a 5,000 lb. gross weight trailer with any of the current or on the short term drawing boards trucks on anything other than the Bonneville Salt Flats is a non starter for us.

I cancelled the Lightning order but went ahead with the ID.4. The AWD VW is everything we had expected and more. We have 3 years free charging from Electrify America and a 48 amp Clipper Creek Level 2 charger at home. In addition, we have a 17kW roof solar system so charging, for us, is free. Yes, we paid up front fir the solar system, but we were paying $6,000 a year for PG&E so our pay back is going to be short.

While people talk about the EV charging infrastructure in terms ranging from workable to dismal, they are talking about charging cars and trucks. If the discussion was turned to charging an EV towing a camper, the state of the charging infrastructure would quickly head South. I have yet to see a charging station that would charge a tow vehicle while hooked up to a trailer. Unless you are willing to take up all the other available charger parking slots, unhooking is currently the only practical option. Drive through stations are something yet to be considered by charging station operators.

One possible, but not yet fully explored option would be for RV parks to set up for charging. A level 2 portable charger could certainly charge most currently available EV batteries overnight, but I am guessing that plugging into a 50 amp AND 30 amp pedestal will not be a popular practice in the eyes of RV park owners.

I was disappointed to cancel the Lightning, but I am not willing to deal with real world daily tow limits in double digits. Instead, I bought a mild hybrid RAM that will have to do until manufacturers decide to purpose build an EV for towing campers.

[chuckwhanson]

Sounds great to me. I’ll be retired in a few years when all this comes together. But isn’t the problem is the highways? Hard to keep 50 on those.

I believe by saying he assumes 50 mph while traveling, that includes stops (for gas, bathroom breaks, food, etc.). That is, to cover 350 miles in a day, assume that will mean 7 hours of total traveling time. I have found that to be a good rule of thumb as well. As the OP said, sometimes it's less, sometimes more, but to assume you will cover 50 miles every hour is a good rule of thumb. I generally do a bit better than that (closer to 55 miles), but if, for example, you take a dine-in lunch break, your average will drop of course.

[bborzell]

This is a followup from the test I mentioned earlier.

This compared alFord Lightning with the extended range battery to a ICE truck towing the same trailer. It speaks for itself.

https://youtu.be/-e55Vued028

[GeorgeB]

I understand solar panels put out a minimal amount of power to recharge an EV, but I still can't wonder about the following questions. Please take my questions lightheartedly. Could you charge your EV with RV solar panels as you drive down the road? How long would it take to charge your EV parked on a sunny day with RV solar panels? How many panels would make it a reality to charge a parked EV in two days, three days? Where are the electrical engineers when you need one? Ha HA! I'm very excited to see how this all works for you and where this EV industry will take us. Keep us informed.