We just completed our first multi-state road trip. Four passengers, 100 pounds of luggage, gear, and supplies, 90D, 20" wheels. The high-temp environment (110ºF / 43ºC) was a good stress test for several aspects of the car.
5-seater AC effectiveness in high heat, low humidity environments (Southwest):
Throughout the journey, the four of us were comfortable with the interior temperature set at 64 degrees. The heavy factory tint on the rear glass, the second row roof glass, and the upper part of the windshield seems to help. Airflow to the rear was not an issue, because even though the B-pillar vents are weak, airflow from the front vents makes it to the rear. The center rear vents are also quite strong. I was, however, surprised to find that the front passenger vents were noticeably weaker than the vents on the driver side.
5-seater storage capacity:
This trip gave us a chance to test the storage limits of the 5-seat Model X. We filled every possible area: the rearmost well, the shallow well where the 3rd row seat would normally be, the entire above-floor cargo area, beneath the rear bench, the trunk, and the front door pockets. Compared to my wife's Lexus RX 330, the X easily held twice as much stuff. We do this kind of a trip every year, and typically we have to split supplies between our car and a friend's car. This year, we brought everything ourselves and still had room for three people in the back. A word of caution: the rear storage well gets very warm, so I wouldn't put anything temperature sensitive down there, like food or electronics.
Cabin Overheat Protection:
Range was never an issue for us, so I left the feature enabled. I figured it would be working hard in 115 degree heat, and it did. Twenty (20) miles of range were consumed over 7 hours while parked at the Zion Visitor Center. In doing so, it helped protect some camera gear we had inadvertently left in the back. Plus, it was really, really nice to return to the car after a long day of hiking and not have it feel like an oven.
Supercharging speed in high heat:
Expect charging to taper off quickly. I regularly saw mid-50 kW charging rates even with the battery below 40% SOC. Fortunately, we timed all of our supercharging stops to coincide with meals, so our travel plans weren't affected by the slower charging speed.
Elevation and Heat Soak effects:
Ha! None. Love it.
Other observations:
White interior vs. sand, sunblock, dirt, dust, and road trip junk food:
I was expecting some issues, but no...these seats and side trim clean up very easily. As it turns out, the problematic areas were the alcantera dashboard and upper headliner, and other dark parts, which took extra effort to clean.
Model X Moments:
My favorite moment was when a little boy and his mom drove clear across the parking lot to take pictures of all the Teslas parked at the supercharger in Primm. It was a common theme, actually. Lots of young kids (girls and boys alike) who recognized the cars and tugged at their parents hands, pointing and smiling. There's definitely a buzz among the young crowd. And this was before any doors were opened. Once those FWDs went up, game over.
Overall efficiency over 960 miles:
374 wh/m. This included a mix of 50% efficiency-minded driving (speed limit, or up to 5mph below), 50% fast driving (passing, bursts of "fun"), 100% A/C usage, range mode off (to maximize AC effectiveness), suspension set to VERY LOW.
Charging stops:
To destination
Irvine, CA (overnight 240v charge)
Barstow, CA (supercharger)
Primm, NV (supercharger, 20 min. top-off)
Caesar's Palace, Las Vegas, NV (overnight L2 charge -- charging is free, valet is $18)
St. George, UT (supercharger)
To home
Hurricane, UT (overnight 240v charge)
South Las Vegas, NV (supercharger)
Barstow, CA (supercharger)
I didn't realize this until after we left, but Zion has Clipper Creek L2 chargers in the Visitor Center parking lot. We didn't need to charge, as our home base was only 40 minutes away in Hurricane. But good to know for the future!
Overall, it was a great trip. We really taxed the A/C system on this trip, but the car delivered and always kept us comfortable. We saw so many cars parked to the side of the highway, overheating. Range was never an issue, even with the heat, even during stints of enthusiastic driving, even when going uphill. Tesla's supercharging infrastructure is just fantastic and keeps getting better. St. George is doubling in size from four to eight stalls. Barstow is up to 16 stalls. We never had to wait for a charge, and none of the stations were ever more than 1/2 full.
Our next road trip is just over a month from now. Can't wait!