Ten days ago I flew to Seattle and drove my newly purchased 2012 P85 on I90 back to Iowa, through lots of mountains and extreme cold (38F at start; down to -4F by end of trip 2 days and 2,100 miles later). I first used Tesla.com trip planning tool to ensure I had adequate Superchargers (22 available on my route, 18 recommended to be used) for my P85’s current 251-max mile range (it’s lost about 5% of its original 265 mile range after 6 years and 48k miles), which would only net about two-thirds of that (~165 miles) after factoring in the cold, speed above 55mph, and mountains. And since it makes little sense to waste time “trickle charging” above 90%, nor run too low (below 10%) in freezing temps, my true effective range for my road trip was only 135 miles (251 x 0.8 x 0.67). As such, I actually used 20 of the SCs and skipped only two. My longest distance between two SCs was 143 miles, so before that stretch I charged to 90% (226), drove 70mph (instead of the 80 mph speed limit), and used two bacons (middle setting on heated seats) but very little cabin heat...just enough to defrost my view out the windshield and side windows. I arrived with only 13 miles (5%), but then that MN SC didn’t work! All 4 stalls were tried, each 2-3 times, and my car’s ring turned RED each time! It was 2:40am on a Sunday, and below zero with the wind chill
Tesla rep sitting in his warm cubicle in Utah was unable to help (hour on the phone, diagnosis OTA was that my car wasn’t the problem, rather it must be all 4 Tesla SC units not working, and tow not available until 7am at best!). Thankfully, we had already found a 110v outlet at nearby AmericInn to plug in our home charger and keep charging my battery so the extreme cold didn’t brick/cold soak my battery. It worked, as 90 minutes later, my warm Tesla finally mated with SC stall #3 and I got the happy green ring
Moral of the story is to always have a Plan B (blankets in car, 110v home charger with 240v adapter in trunk, cell fully charged, protein snacks, water, etc) when doing a road trip. I had also used EVtripplanner.com, which was another great tool. But Tesla’s onboard Nav for trips WAS extremely accurate as our journey had virtually all the extreme factors (cold, speed, mountains, wind) and the estimated arrival State Of Charge (SOC) turned out to be spot on! As I turned the heat up, my estimated arrival SOC would keep dropping, and vice versa. Also, as I got aggressive and hit 80mph (cause I wanted to get home), i was given the warning to keep my speed below xx mph if I wanted to make it to the next SC! It even changed the warning speeds I needed to remain below , so the algorithms really seemed to be accurate. I was impressed by Tesla’s accuracy and pro-active warnings.
Also, I just picked up my new 3 MR (with a similar 260 miles max) two days ago at Westmont with 8 miles on the odometer. By 38 miles, my EAP had finished its calibration and worked well through thick fog and lots of traffic. Finally, it was again very accurate in its forecast of my arrival SOC for my Iowa destination. Upon arrival 3 hours later, it was spot on. Well done, Tesla software engineers!