Just wanted to share my story about our first supercharge experience and road trip in our Model X on Memorial Day. Background information of our car: 90D, 20" wheels, active spoiler, 1000 miles on odometer and range mode on. Temps around 88F under sunny skies when leaving GA. We drove from our home in the Atlanta area to Charleston, South Carolina today. We supercharged in Greenville, South Carolina and allowed for the entire 65 minutes needed to go from our 100 estimated miles when we arrived to what topped out at 262 miles when supercharging completed. I was at 90% when departing Atlanta (estimated 240 miles range) we drove 128 miles to Greenvile and arrived with an estimated 100 miles of remaining range. Only a 12 mile difference than initially estimated. We auto pioleted 95% of the way and speed was set to 77 mph so I thought it was extremely efficient. We averaged 335 wh/mile for this initial jaunt. The Greenville supercharger is within walking distance of Whole Foods, Chipotle and REI so 1 hr of charging time even with two kids under 4 years old was easy to kill. Ended up with some goodies too at REI in the process. Now here's where it got very interesting. After charging full to 262 miles in Greenville our Charleston destination remained 220 miles away. 42 miles of estimated buffer is a little too close for comfort for me but knowing the weather was going to mostly cooperate, the temps were toasty and we would go 1000' down in elevation en route I was confident we would make it (if not we could go to the Santee Supercharger although it is a good bit out of the way). I set autopilot in motion and kept speed at 65 mph, what I've read here to be the sweet spot for X efficiency. Check out the stats below of what I was able attain. Important to note the last 60 miles of our trip ended up being in moderate to heavy Tropical Depression Bonnie rains. Our Wh/mile managed to drop down to around 315. I also followed our trip meter total energy tab to see how many miles both 85 kwh and 90 kw hours provided under my above mentioned conditions from Atlanta to Charleston. At 85 kWh of usage I had driven 270 miles while 90kwh of usage rendered ~290 miles of actual driving. To sum it all up. I was estimated 262 miles of range, I drove 220 actual miles and arrived with 48 miles remaining. I think the 90X on 20" wheels can easily get 270 miles if kept between 65-70 mph under ideal weather conditions (elevation permitting). Going 65 in a 70 mph speed limit was really a not a big deal for me today as being a holiday weekend there were dozens of cops hiding everywhere the entire route and it was 1 less thing to worry about. Hope you find this info useful! PS....I'm very very glad I got the 90D over the 70(5)D and auto pilot performed heavenly. Cannot begin to describe how I feel about this amazing technology. I was telling my wife the auto pilot alone is worth the 6 figure price point!

It's great to hear the real-life wh/mi statistics vs the EPA testing. Curious to see/hear how the 75D's wh/mi statistics are. The back of the envelope calculates make the 75D EPA figures to be 300wh/mi vs. 330-ish wh/mi based on EPA miles for the 90D, less 5kw on both packs for brick protection.

Nice numbers. Going downhill is huge, you wouldn't be able to get those numbers on the opposite side of the road (going uphill).

Congrats on your new Model X. By the way, I don't think there is such thing as "65 mph sweet spot for Model X", aerodynamic drag goes up exponentially as speed goes up, it is all dictated by physics. The slower you drive (until around 30 mph), the better it is for range. I am not saying you should drive 30 mph on highway, but if you are close to running out of juice. Try to slow down as much as you can and/or trail behind some big truck. And 55 or 60 mph is certainly more efficient than 65 mph "sweet spot".

What he said. My resutls driving from 6000' elevation to 300' were quite different than driving from 300 to 6000. Unfortunately (as others have pointed out on this forum) Tesla doesn't estimate elevation changes so beware. I have a friend who has a daily commute from 9000' to 6000' and he sees it underestimate the range down by 50% and overestimate the trip back up by about the same amount.

My wife being the is the driver of our X. Neither she nor I use autopilot except to show off the capability to others. We have about 2000 miles on the car now and have consistently hovered in the 300 whr/mile range. Life in the Atlantic coastal plain has some benefits.

Tesla has said in the past that cruise control is more efficient than humans, but I suspect that is on the average case. A human that has sorted out how to effectively hyper-mile a Tesla and adjusts for terrain is probably more efficient. On flat surface, the machine is likely more efficient.

The typical optimum efficiency for electric vehicles is about 15-20 mph. This is true for the Model S and so is very likely true for the X as well. As a rough rule, you can probably drive twice as far at 20 mph than at 70 mph.

Thanks, great information. Glad they have the Greenville SC open after the delay. Helps a lot with I85 North.

Pjjava34 Thanks for trip report.....in a (similar vehicle/mileage) recent 800mile trip I got an average of 343 Wh/mi with similar numbers on highway vs. off to yours. On average lost 14% from 264 rated range miles but wasn’t in range mode and had thermostat at 71 degrees. Please advise what you average when going uphill back home.....

1st long trip from Scottsdale to Tucson today. Did my first (and second) supercharges. Here's some stats from the day about wh/mile at different speeds and supercharger info. 75 mph with range mode on got 326 wh/mile / 90kw full charge is 273 range 75 mph with range mode off got 372 wh/mile (242 range) It was 90 outside and I had air at 70. Later in the afternoon it was 105 outside and air at 68 (no tint yet). 80 mph range mode on since it works 414 wh/mile (217 range) Stopped at supercharger on the way down: 188 rated miles left. Got to 232 in 16 minutes (+44) Stopped at supercharger on the way up: 41 rated miles left got to 131 in 30 minutes (+90) Thought supercharger rate when battery was mostly full would be slower and when it was almost empty would be faster. Big surprise 30 minutes only got me 90 miles.

Thought supercharger rate when battery was mostly full would be slower and when it was almost empty would be faster. Big surprise 30 minutes only got me 90 miles. Matt: Question-when you received the slower charge rate were there others at the SC and we you "sharing" with another vehicle? I have found some differences in the FL/GA/Carolina's SC but universally vehicle charged more quickly when "empty"

Nope, I was the only one there both times. How many miles do you typically pick up in how much time? Does that indicate there's a problem with my car?

The other day I was the only one at the SC and came in at 8%. I was charging at about 300 mph. It took about an hour to go from 8% to 90%. About another hour to get to 98%. Another half hour to get to 99% and then I gave up because it was charging at about 2 mph.

Reason why I asked is that if you are “sharing (A & B) at a SC you can find you power is subdued with first Tesla at charger getting more energy. I looked at my last trip and reviewed a couple of stops that would match yours (around 15% start, 50% end, +90 after 30 minutes). As an example, in 30 minutes, @ Savannah SC, I gained 115 miles, @ Lake City I gained 92 miles in 19 minutes (started at 12%) vs. your 90 gained in 30 minutes in AZ. Must be that particular SC idiosyncrasy......suggest you take periodic pictures of the Tesla APP during your SC stops to see speed of charge per particular location and/or to ensure that your slot is charging quickly. I’ve read where changing to a different slot can also make a difference.