Towing with Electricity and a Model X

[fwjumper]

I'm excited at the idea of folks doing what you are doing. BTW, congrats on the new AS. Hope you get the bugs fixed quickly and well. The Tesla thing is neat and as far as the 150 mile range goes...at my age I need to stop by then anyway, regardless of how much remaining fuel I have. I guess it will be a while before there's an EV that will tow a 34 or the new 33. We have become minimalists in many ways, but we haven't mastered it with the AS yet. Great luck and fantastic travels to you!

[ohmman]

I've uploaded a photo of the car with the AS. Let's see if I can embed it here...

[cwf]

Hope all this ends great for you!... different strokes..

The rivers of debates over tech runs deep all over. If a car/vehicle ran on squirrels, rubber bands doesn't matter to most if the benefits are clear... such as a pup tent vs Airstream.

Good luck on the test!!! It will add to the river level and may improve the water quality...

Respectfully submitted...

[SteveSueMac]

Originally Posted by ohmman

I've uploaded a photo of the car with the AS. Let's see if I can embed it here...

Doesn't get much cooler. Thanks for all the insight. Happy camping!!

[fwjumper]

Airstreams usually draw attention in non AS parks. The attention you will get will be exponentially higher. Get ready for your tour guide duties and enjoy it. The photo is great and the pair look like they are made for each other. Tell us everything, the good and the not-so-good. I'm guessing it will be mostly the former. Thanks for the pic.

[rvb]

Originally Posted by Jacob D

I don't have a Tundra, but I would be willing to bet you have a bigger gas tank than that. Maybe you need a new gas gauge.
My Chevy 1500 Silverado has a 33 gal tank and a terribly unreliable gas gauge. I can drive 230 miles towing with gas to spare but the gas gauge makes me nervous so I stop and put in 20 gallons.

200 miles is a good stopping point to stretch legs, use bathroom, snack etc...

Pre-2016 Tundras are indeed 26 gallons. My dealer verified it, the gas light comes on at 23, gauge hits bottom at 24.5 and the most I have ever put in was 25.7 gallons after we coasted in to Roswell on fumes. (I was napping, wife was driving, no stations for 100 miles), We get 10-11 mpg and plan to stop at 200 miles which gives us about 50 miles to find a station.

[rvb]

I just saw the picture, We are always looking for other Airstreams when on the road and have to say yours is a a great looking combination!

[thiel]

Originally Posted by rvb

200 miles is a good stopping point to stretch legs, use bathroom, snack etc...

Pre-2016 Tundras are indeed 26 gallons. My dealer verified it, the gas light comes on at 23, gauge hits bottom at 24.5 and the most I have ever put in was 25.7 gallons after we coasted in to Roswell on fumes. (I was napping, wife was driving, no stations for 100 miles), We get 10-11 mpg and plan to stop at 200 miles which gives us about 50 miles to find a station.

Thanks for fixing my brain. All this time I had two hours in my head when I meant two hundred miles. 50 miles grace is grace.

[McDave]

Your comment on how little power a parked trailer uses compared with an electric vehicle makes me wonder about the cost of recharging it in a trailer park. Now, the electricity is included with the daily space rent. As use of electric vehicles increases, I wonder if that can continue? If the cost of recharging an electric vehicle is significant, I can foresee a time when our use of electricity is metered, or perhaps will be included in the space rent up to X KWH, with additional charges for electricity beyond that amount.


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[Wanna EB]

Very cool rig. I am now 2 1/2 years into my Tesla Model S. The range question seems to terrify a lot of people. It never crosses my mind. And, once you go Electric, there's no going back.

That said, because we will be often in the middle of nowhere southwest USA, I will be using a diesel until the batteries and infrastructure grow a bit.

Thanks for sharing.

[wulfraat]

I love our EV. We use an electric bmw i3 to offset the cost and environmental impact of our airstream tow vehicle (2012 Infiniti QX56)

We have dubbed our bmw i3 "the free car" because we used to spend $300/month fueling our SUV as a daily driver. We have since parked the SUV (only ever use it for towing now) and the bmw lease cost + monthly electric bill for the i3 (new daily driver) is less than what we spent in fuel for the SUV. 2 vehicles for the price of one. Love EVs.

[cazual6]

Awesome pic!!!! drrroooollllll.....

[slowmover]

Range with an ICE TV is 80% of max fuel capacity with an accurate average already in place.

These things are always hypothetical, but that's a standard used in industry.

One has to also factor first climate, then terrain, then driver motivation if any sense at all of comparisons is to be made.

On an ICE the percentage change should be no more than 40% from solo to towing where other factors are the same. It can trend down to 30 with a well chosen and well sorted combination.

One wants a "true" average. Same for EVs.

If I state I have a 435-mile "average" range, one has to know the other factors affecting that number.

So, what's the percentage towing penalty (same solo weight, road speed, and round trip, etc) with an EV?

Range is relative. Percentage change is closer to "true".

[HowieE]

Originally Posted by ohmman

One of the windows has a gap between the front trim and the body. Insulation was coming through. Techs at my location (Bay Area Airstream Adventures) said that they were unable to close up the gap and that it's not uncommon. There are other window fitment issues that seem sloppy, but nothing that seems to be a major functional issue.

Some other careless details include window caulking issues, sink drain caulk, which is partially missing, stripped screw heads on the Fantastic Fan cover, some rusted screw heads on the outside of the vehicle, etc. Again, nothing terribly functional but also not terribly impressive for a leader in the RV world.

I read you's and the comments of others on the Tesla and it's towing characteristics but would ask to to open a separate tread on the window gap issue. There is no reason for such a situation to happen let along a reason to say it can't be fixed.

You should be interested in having it fixed as that is a leak point and leaks do damage to Airstreams over time.

If you start a tread please post a picture of the gap.

[Countryboy59]

Originally Posted by McDave

Your comment on how little power a parked trailer uses compared with an electric vehicle makes me wonder about the cost of recharging it in a trailer park. Now, the electricity is included with the daily space rent. As use of electric vehicles increases, I wonder if that can continue? If the cost of recharging an electric vehicle is significant, I can foresee a time when our use of electricity is metered, or perhaps will be included in the space rent up to X KWH, with additional charges for electricity beyond that amount.


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It costs about a buck to charge an EV...

[ohmman]

Originally Posted by HowieE

I read you's and the comments of others on the Tesla and it's towing characteristics but would ask to to open a separate tread on the window gap issue. There is no reason for such a situation to happen let along a reason to say it can't be fixed.

Thanks, HowieE. I've created a new thread here.

Originally Posted by slowmover

If I state I have a 435-mile "average" range, one has to know the other factors affecting that number.

So, what's the percentage towing penalty (same solo weight, road speed, and round trip, etc) with an EV?

Range is relative. Percentage change is closer to "true".

I don't completely understand your question, as it reads slightly cryptic to me. However, I think what you're asking is compared to normal range on the TV, how does my trailer specifically impact it. Clearly you can only compare similar pairs, and the trailer impacts it differently depending on the factors you name - climate, elevation change, etc. A heavier but aerodynamic trailer will do better on flat ground than a light trailer with poor aerodynamics. Especially as speed increases.

I can give you a data point. This trailer and the Model X appear to consume right around 575Wh/mi at 55mph in "ideal" conditions. The Model X alone consumes around 330Wh/mi at 55mph in "ideal" conditions. So in that condition, there is a 74% penalty pulling the 22' Sport. However, as soon as I start to climb a hill, that number will become invalid. Additionally, coming down a hill will invalidate the number because I can recapture not only my Tesla's momentum into battery storage, but the added kinetic energy from the trailer. Battery regeneration appears to be able to capture everything from both vehicles even on a 9% grade. So it's quite possibly more efficient downhill compared to having just the vehicle.

This is why a range of ranges is best. I have taken data from another couple hauling the same trailer with the same Tesla and shown that depending on conditions (hills, load, climate), the true range is in the 110-150 mile range. They were able to go further with elevation losses, but nobody cares about how far one can go. They care about the lower limits. Those numbers are real-world realistic numbers for most conditions. It is quite possible that towing in heavy cold rain up a mountain without any downhills would limit the range under 100 miles. But that's as much of an outlier as going down a hill on a sunny warm day with a tailwind and getting 300 miles. Averages are valuable when they're rooted in reality.

[slowmover]

Yessir, that's what's being looked for:

Range over a given route solo (but with all passengers and gear as of camping; simulate weight with sandbags if need be).

Same with TT over same route also loaded for camping. Full fresh water and propane. Etc.

A pass cross a CAT Scale for the combined rig. Then drop trailer and cross again to get solo weight with everyone aboard.

On another day, meet that weight goal to do the test route.

All rigs suffer from large to tiny rolling resistance problems. First is setting hitch (if need be).

If the percentage change is 74%, that's enormous.

I'd bet there was room for improvement. Mechanically, and with driver.

To some it may not matter. To others it will.

There's a method to ironing things flat.

[jcl]

I think understanding the "towing penalty" to range is critically important.

What I am not clear on is the comparison to an internal combustion engine (ICE).

Slowmover, you have previously referenced a 40% penalty as a rule of thumb. I have no info to dispute it. However, I saw you calculate it in a previous post as 21 mpg solo, 12.5 mpg towing, with a calculated 40% reduction. Importantly, that is a mpg difference, not a range difference. Using a standard liters/100km conversion, which puts consumption in the numerator, and thus creating figures that are logical to subtract one from another, the 21/12.5 shows a 68% increase in consumption. This would imply a 68% decrease in range. Using that yardstick, the EV figure of 74% higher consumption doesn't seem as far off. Add to that the energy recovery when descending, which an ICE can't do, and the unknown hill climbing penalty, and it gets even murkier.

Another metric would be cents per mile. Slow, you show an 80% penalty in CPM when towing, in your signature line, but I don't know what other factors are involved, and how many of them would carry over to an EV.

Interesting topic.

Jeff

[Nuvite-F]

Originally Posted by Countryboy59

It costs about a buck to charge an EV...

Let's run some numbers. The original poster says his Tesla X has a usable battery capacity of 84 kilowatt hours (kWh)

Originally Posted by ohmman

It's hard to get one's head around the battery capacity and the energy used to move a vehicle. My X has a 90kWh battery, which includes about 84kWh of usable capacity.

Depending on where you live, electric rates in the US seem to run 10 to 15 cents a kilowatt hour. My latest home electric bill comes in at 11 cents a kilowatt hour.


So 85 kWh x $0.11 per kWh = $9.42 to fully charge the battery.


One can readily imagine that a campground would charge extra for the energy cost to recharge an electric tow vehicle.



Let's also consider for a moment the time required to charge.


If the camp site is equipped with a 120 Volt, 30 Amp outlet the maximum output is 120 V x 30 A = 3.6 kW. At that rate it will take


84 kWh / 3.6 kW = 23.3 hours to charge the battery, assuming 100% charging efficiency, which is somewhat optimistic.


If the camp site is equipped with a 240 Volt, 50 Amp outlet the maximum output is 240 V x 50 A = 12 kW, which would charge the battery a lot quicker,


84 kWh / 12 kW = 7 hours, again assuming 100% charging efficiency and the entire output of the pedestal to charge the tow vehicle with nothing left over to power the trailer.


Finally, given the fact that a lot of campground distribution systems are plagued by tripping breakers on a hot day when everyone is running their air conditioning, one can readily imagine that more than a few tenants drawing 100% power output from their power pedestals would be enough to take down the campground's system. But I don't expect this will be a problem very soon.

[Countryboy59]

Not likely to cause an issue as electric vehicles are a very, very small percentage of what's on the road and probably even smaller percentage of vehicles at a campground. But I don't doubt some people will make this an issue. I had neighbors bang on my door in the past, concerned that my porch light was gonna take down the grid on hot days.