Howdy! After 50 years my wife and I are relocating to the Austin, Texas area from Columbia, Maryland. The road trip in our Model 3 standard range plus begins on Friday and I plan on using the in-car navigation to go from supercharger to supercharger, taking approximately 4 days. The car will be packed with about 100 lbs of added weigh in luggage. My questions are: how much will the added weight affect my mileage. How much buffer in reduced mileage should I allow to affect the projected mileage between superchargers. (you know what i mean) What is the best way to distribute the additional weight. And anything else I need to prepare for, problems in wi-fi coverage, etc. All comments appreciated.
Get your tires up to 45PSI or so (cold). Make sure your Aeros are on.
On your first Supercharger leg, make a note of the predicted arrival % and then note what you actually arrive with - just to calibrate yourself about the estimates.
Weight matters when it comes to miles consumed going uphill, but you get most of it back when going downhill. It definitely matters, but not as much as you might think.
I recommend charging to at least 10% above what the in-car estimator predicts until you are comfortable with how the predictions and actual arrival charge are working out. This will allow you to travel faster and gives you margin in the case of weather/cold/short side trips. Remember the closer you get to the charger the faster you can drive (if you have margin) - but if you are far from your destination definitely heed any warnings about reducing speed.
You can log in to ABRP on your in-car browser in advance and enter your live data (if you are comfortable giving them your login credentials...) to be able to have something to compare to. However, I found a few bugs and I didn't find it to be a lot more accurate than the in-car estimator (once I had the appropriate wheel configuration selected). However, ABRP is nice for providing a better trip overview than the in-car estimator.
I don't find the in-car trip planner to be very good at picking Supercharger stations (ABRP is a bit better I think but even that I had to override when there were a lot of options). So don't just plug in your destination and do what it says. Optimize. You want to arrive at Superchargers with a low state of charge (but not too low of course). Start with 15-20% arrival target and then reduce that to 10% when you are comfortable with how things work. With an SR you may have less flexibility on Supercharger stops so maybe it matters less (there may not be much optimization possible).
Turn off all the big sources of drain (Smart Summon Standby, Cabin Overheat protection, etc.) just to make sure you don't get any surprises overnight if you weren't planning to have any drain. Or leave them on, but expect a large amount of drain, and allow for it.