2016 Tesla Model X: Tow Test Recap
by Dan Edmunds, Director of Vehicle Testing
It doesn't take long to find yourself climbing a grade when you drive out of the Los Angeles basin. After all, the place is hemmed in by mountains. Just a few miles into the trip our 2016 Tesla Model X began a steady 5-mile ascent of the Sepulveda Pass, a 1,130-foot prelude of things to come that didn't even get us out of the sprawling L.A. area.
This modest 3 percent grade doesn't feel like much unless you're towing something, but that's exactly what we were doing. This was the start of a four-day towing adventure with a Happier Camper HC1 trailer. Our target lakeside campground lay almost exactly 500 miles ahead of us, a distance we figured would take two days to cover based on an earlier experience with range and recharging while towing on Tesla's Supercharger network.
We headed out of L.A. while everyone else was commuting in, so traffic was light in our direction. As I would the entire trip, I set the cruise control to 55 mph, which is California's maximum towing speed limit. But this was also a good way to rein in the additional consumption that comes with pulling a box on wheels. Aerodynamic drag increases in proportion to the square of speed, so towing at 65 mph generates 40 percent more drag than towing at 55 mph.
Right away, the Sepulveda Pass demonstrated what I love about towing with an electric vehicle. Many of the difficulties associated with climbing a grade simply disappear. A direct-drive electric motor never shifts; the revs have no need to climb. The Model X can generate so much power and torque that it never strains, never gets any louder. And the Tesla's cruise control is so unfailingly precise that your chosen speed never waivers even a half a mile per hour. Uphill, level ground — even downhill — it all feels exactly the same.
The main source of drama was the electricity meter, which climbed rapidly to the top edge of the graph and exceeded the limits of the scale. The car's estimated range calculation began to tumble alarmingly in real time. The projected range calculation righted itself somewhat after crossing the summit and heading down the other side, but even on flat ground the presence of the trailer resulted in consumption that was much higher than what we normally see.
First Stop: Mojave, California
The highway ends at this small desert crossroads town, so it was time to disengage the cruise control and work our way through the few signals that stood between us and our first Supercharger stop. Regenerative braking kicked in as soon as I eased off the throttle, and it proved to be just as powerful and controllable as ever. At the stop, I was able to comfortably one-pedal it down to the last 5 mph before touching the actual brakes.
Mojave's Supercharger takes up six spots in front of a Mexican restaurant, and we arrived to a deserted lot about 30 minutes before lunch hour. I considered detaching the trailer, but these are nose-in stalls and the aisle was wide. The HC1 wasn't sticking out even halfway, and the early lunch arrivals were getting by just fine. They seemed amused at the sight of a Tesla with a cute trailer rather than peeved at my admittedly questionable parking tactics.
We needed food, and the Tesla needed to be full because the next leg included the possibility of skipping a Supercharger if we could manage 118 miles. Last year's exploratory tow test suggested this distance was far from a slam dunk, especially in 100-degree weather with 1,000 feet of elevation gain and the distinct possibility of strong desert headwinds. Batteries fill quickly at first, but the charge rate rolls off and flattens out significantly past the half-full point. Our full fill took time.
Drive distance: 94.9 miles
Drive time: 1 hour, 52 minutes
Consumption: 564 watt-hours (Wh) per mile
Charge time: 1 hour, 37 minutes
Second Stop: Inyokern, California
When we left, the predictive range meter said the Model X would arrive in Lone Pine with a battery surplus of 27 percent. But that began dropping soon after we got underway, and at a quarter of the way there, it had fallen to 20 percent. I turned the air conditioning off to save energy, but the Model X's weird glass roof made this miserable.
It didn't seem to help as the meter kept dropping into the teens. At one-third distance, the projected battery life had dropped to 14 percent as the Inyokern turnoff sign appeared. With most of the mileage and elevation gain still to come, I made a snap decision to divert to the Supercharger station we'd wanted to skip. Drat.
Inyokern's Supercharger was dinky, with just four back-in stations in a lonely lot behind a corner market. No one was around, and a Tesla Club caravan seemed unlikely to appear, so to avoid unhooking the trailer, I parked sideways to put the charge port within reach. The HC1 blocked just one extra spot, so it seemed a good risk since this was a short insurance top up, not a full fill.
Drive distance: 48.3 miles
Drive time: 1 hour, 13 minutes
Consumption: 536 Wh/mi
Charge time: 25 minutes
Third Stop: Lone Pine and the Alabama Hills
The Lone Pine Supercharger was now only 69 miles ahead, and the extra Inyokern juice made the going easy. The range meter prediction dropped again about 10 minutes after I got underway, but it didn't matter. We rolled into the Lone Pine Supercharger just before quitting time and decided to set up camp in the nearby Alabama Hills, site of many old Western movie shoots.
But the next day's first leg looked to be brutal, with 4,100 feet of elevation gain. We decided to get a head start on filling the battery tonight before we headed for the hills to set up camp. Besides, a highly rated barbecue joint was within walking distance of the Supercharger. The car could charge while we ate. Multitasking is the key to taking the sting out of charging wait times.
There was a catch, of course. The Lone Pine Supercharger was buried in a tight lot behind the museum. There was no room for any creative parking shortcuts. I had to unhitch the trailer, lock the tongue, drive the Tesla into a charge stall, and hope no one ran off with the trailer while we ate.
Drive distance: 69.2 miles
Drive time: 1 hour, 37 minutes
Consumption: 561 Wh/mi
Charge time: 1 hour, 5 minutes
Day One Summary:
Drive distance: 217 miles
Total time: 8 hours, 9 minutes (5 hours, 2 minutes driving; 3 hours, 7 minutes charging)
Effective travel speed: 26.6 mph
Average consumption: 555 Wh/mi
The previous night's dinnertime charge had brought the battery up considerably, but it hadn't filled it completely. The leg to Mammoth would be the most challenging of the trip, with 99.6 miles to cover with a 4,100-foot elevation gain. A couple of intermediate summits lurked along the way, so in cycling terms we had over 5,200 feet of climbing ahead of us.
We needed all the juice we could get, so we disconnected the trailer and plugged in at the Lone Pine Supercharger once more to finish the job while we ate breakfast at a nearby diner. We paid the check and walked back to find a full battery.
Charging and eating time: 46 minutes
Fourth Stop: Mammoth Lakes, California
A morning start gave us cooler weather, so I was able to crack a window and keep the air conditioner off. This stretch was loaded with stunning scenery, which helped pass the time for the two-plus hours it would take to cover the distance.
Most of the climbing took place in the final 30 miles, and once the grade took hold the range sank into the low teens almost immediately. But I had no Inyokern-style diversion this available this time; I simply had to make it. So I trimmed my speed to 53 mph and kept the A/C off even as the sun began to beat down through the glass roof.
The meter dropped another tick to 12 percent before stabilizing, and then the grade flattened with about 10 miles to go. We arrived and plugged in with 13 percent battery left over, the closest shave of the trip.
The Mammoth Lakes Supercharger is the only one I've ever encountered (out of the 40 or so I've visited) that's suitable for trailers. It has pull-through spots arranged in nose-to-tail pairs, extra-wide stalls, and the whole thing occupies an island in the middle of a sleepy lot. It'd be easier to maneuver bigger trailers through there if the stalls were angled instead of perpendicular, but our diminutive HC1 trailer didn't care. We walked off and sat down at the patio of a local eatery for one of the best burritos I've ever had as the nearly empty rig sat charging.
Drive distance: 99.7 miles
Drive time: 2 hr 7 min
Consumption: 650 Wh/mi
Charge time: 1 hr 50 min
Fifth Stop: Gardnerville, Nevada
The next leg to Gardnerville, Nevada, was just as long as the run to Mammoth, but this time we descended 3,000 feet. The sun was higher now, so I took a moment to install the Tesla's embarrassingly cheap overhead sunshade. It seemed to help some, especially since the downhill-trending route allowed me to run the A/C as much as I pleased.
We found the Gardnerville station at Topaz Lake. Like Inyokern, these were back-in spots. There were no other Teslas in sight, so I felt confident I could get away with parking sideways without impacting anyone else, especially since I was only taking up two of the six spots. This was the last stop before our final destination, but since we'd arrived with 40 percent battery, it only took a little more than an hour.
Drive distance: 99.4 miles
Drive time: 2 hours 45 minutes (includes 30-minute stop for video, construction delay)
Consumption: 439 Wh/mi
Charge time: 1 hour 8 minutes
Sixth Stop: Boca Reservoir, California
The drive to our campsite started off with a smooth climb up to Lake Tahoe, where we skirted along the shore for a bit before we turned north and headed for Boca Lake. But within a mile of camp, we encountered a detour. The road across the dam was unexpectedly closed, so we had to take a 15-mile detour on dirt roads that had become greasy from recent rain.
You want to know why I fully fill the battery when towing despite the extra time it takes? Because of unexpected situations like this detour. Headwinds are another huge drain you can't reliably predict in advance, and they can be pretty fierce along this particular route.
The detour added almost an hour to our day, so we were too tired to cook anything when we arrived. Instead, we unhooked the trailer and left it at camp while we drove to nearby Truckee, California, for dinner at a brewpub that happened to have a Supercharger in its parking lot.
Multitasking made the time to complete this charge essentially invisible, and the next morning we would be able to sleep in, enjoy the lake, and get on the road with enough electricity to get underway without the need for a morning top-up.
Drive distance: 104.9 miles (plus another 8 miles back to dinner)
Drive time to camp: 2 hours, 57 minutes (includes detour on narrow dirt roads)
Drive time to Supercharger: 16 minutes
Consumption: 530 Wh/mi
Charge time: 1 hour, 24 minutes
Day Two Summary:
Drive distance: 308 miles
Total time: 11 hours, 48 minutes (8 hours, 4 minutes driving, 3 hours, 44 minutes charging)
Effective travel speed: 25.4 mph
Average consumption: 539 Wh/mi
The Road Home
We went home the same way we'd come, and the going was much easier because of the general downhill trend. We made similar stops in Gardnerville and Mammoth on Day Three, and the long downhill run from Mammoth allowed us to roll into the Alabama Hills for another night's camping without stopping to recharge first.
Day Three Summary:
Drive distance: 283 miles
Total time: 9 hours 36 minutes (6 hours, 47 minutes driving; 2 hours, 49 minutes charging)
Effective travel speed: 29.5 mph
Average consumption: 496 Wh/mi
Because we'd rolled in without charging the night before, the final morning began with another visit to the Lone Pine Supercharger and another unhitch-rehitch trailer exercise, which isn't as bad as it sounds because I'd got it down to 90 seconds at this point. The car only needed an hour to recharge more or less fully, and that suited our breakfast plans just fine.
With a slight downhill trend working for us this time, we were able to skip the Inyokern station and make a beeline for Mojave. We charged there and let the trailer hang out once more before heading for home.
Day Four Summary:
Drive distance: 213 miles
Total time: 7 hours, 5 minutes (4 hours, 48 minutes driving; 2 hours, 17 minutes charging)
Effective travel speed: 30.1 mph
Average consumption: 505 Wh/mi
A Clear Result
Let's boil this down to one set of figures for the entire trip. On the road to Boca Reservoir and back, we traveled a total of 1,037 miles, and the Happier Camper HC1 trailer was latched behind for 1,013 of them.
Travel time: 39.94 hours (25.59 driving, 14.69 charging)
Average travel speed: 26.0 mph
Average Supercharger plug-in time: 1 hour, 13 minutes
Average energy consumption: 524 Wh/mi
Compare that to last year's trip with the Off the Grid Rentals adventure-style, off-road teardrop trailer. On that trip we drove to Flagstaff, Arizona, and back. We drove 1,033 miles in total, and the adventure trailer was in tow for 1,003 of those miles.
Travel time: 40.25 hours (23.02 driving, 17.23 charging)
Average travel speed: 24.9 mph
Average Supercharger plug-in time: 1 hour, 34 minutes
Average energy consumption: 612 Wh/mi
As you can see, the Happier Camper HC1 made a huge difference. Its smooth and stylish shape more than made up for its larger frontal area. Our Tesla consumed 14 percent less electricity (524 Wh/mi versus 612 Wh/mi) and that allowed us to save an average of 21 minutes at each and every Supercharger stop (1 hour, 13 minutes versus 1 hour, 34 minutes).
This is huge, and it really adds up when you consider we made 10 charge stops during the course of the trip. Our total travel time doesn't show what should be a 3.5-hour time savings, however, because of numerous road construction delays and several stops we made to shoot video segments. Neither of those had been a factor in my previous trip to Flagstaff.
Still, towing with a Model X is slow going compared to towing with something running on gasoline or diesel. And that's why I have such mixed feelings about this result.
On the one hand, the Tesla Model X is a pretty effortless tow vehicle. It has plentiful power and torque, it's supremely stable, the air suspension keeps the butt end propped up, the cruise control is impeccably accurate on any kind of grade, the cabin is utterly quiet and, of course, there is absolutely no shifting.
And I really loved the Happier Camper HC1 trailer. I want to tow this rig again on a longer trip with any number of tow vehicles.
But the Model X and the Supercharger network that supports it are simply not up the realities of this kind of trip. With one "Mammoth" exception I know of, Superchargers are not made with towing in mind. We might have had more trouble if we had been towing on a weekend, but we were traveling midweek. And it simply takes too long to charge. Consumption is dramatically higher when towing, so that means you'll be flirting with a full fill from a nearly empty starting point. Sure, you could say we could have unplugged sooner here or there, but do you really want to risk running out if you encounter unforeseen headwinds or detours? Also, you can't go very fast. We were helped by California's 55-mph speed limit, but other states permit towing speeds that are 10 to 15 mph higher. If you want to avoid running out of power, you have to drive slow.
It seems to me the Model X is best suited for local towing that does not involve Supercharger stops and road-trip distances. But you could easily tow a boat from your home to a local boat ramp. Or you could be like the guy I met that uses a Model X to tow a horse trailer 30 miles to the riding area he frequents.
But forget about trying to get out of town to go camping in the mountains for the weekend. We spent too much time on the road and not enough time at the campsite. And don't even think about towing your race car the length of the state to get to the next event — something I used to do with regularity before I got married. Towing any distance with a Model X is only tolerable if you're OK with covering less that 300 miles per day and you've got all day to do it.
And that's a shame because towing on electricity is otherwise pretty great. If the battery-swap idea comes back to life or near-instant charging ever becomes a thing, I'm back in.