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Thoughts and Lessons Learned after a one-week, 2,100+ mile IL-OK trip

Discussion in 'Model S' started by JClu, Apr 10, 2017.

  1. JClu

    JClu Member

    Oct 15, 2016
    For my 100th post on TMC, I'd like share my thoughts and lessons learned from our recent 2,170-mile trip between Chicago and Oklahoma with our 6-month-old S 90D (AP1).

    Trip Planning

    As suggested by many other experienced EV drivers, I did some careful pre-trip planning using a few different methods. is helpful, and the new EVTO-Tesla app shows promises. However, because we have young kids and we know it takes time for the whole family to take breaks on the trip, I was not too concerned about absolutely optimizing "charge time vs trip time." We had to stop every 1.5 to 3 hours anyway, and the car was always ready (in terms of minimal charge needed to reach the next SpC) before we were done with our breaks. Having said that, I learned these 2 things:

    1. The onboard trip planner in the car is very conservative in terms of the initial estimate of arrival battery SOC of whatever destination you put in. In other words, it overestimates the energy needed to reach the destination. This makes sense, as by default Tesla doesn't want us to be stranded with a dead battery because we underestimated the minimal battery charge needed.
    2. With a larger battery like our 90D, we can often comfortably "skip" a SpC with the current layout of SuperChargers in the U.S.


    We have AP1, which as of when the trip took place (March 2017) was superior to AP2. We had Firmware 8.0 (17.4.14) on this trip (just updated to 8.1 a few days ago). For the most part, AP worked well throughout the trip, with the following exceptions:

    1. Whenever we were in the right lane of a freeway and an exit lane appears, AP tends to veer to the right into the exit lane, requiring me to manually steer back several times. This occurred even when the lane markings were present on both sides (granted, the markings on the right were temporarily dotted instead of solid, to signify the upcoming exit). As a result, I became more vigilant in keeping the steering wheel straight when highway exits appeared.
    2. For two times, AP all the sudden reduced speed drastically (e.g. 65 down to 45 MPH) even though there were no changes in road or driving conditions (i.e. speed limit did not change, the car ahead did not slow down, we were driving straight on a freeway in sunny conditions). I could not explain this behavior. Each time I just manually disengaged AP and re-applied it moments later.

    I'm not too bothered by these 2 hiccups; these are just my observations. I recognize that AP is a driver "assistant" feature and not meant to take over the entire driving experience (nor do I want it to, which is why I'm not as upset about "missing out" on AP2 by a few weeks as some other people).


    I will post my reviews later about each individual SpC location that we used (Country Club Hills, IL, Normal, IL, Springfield, IL, St. Charles, MO, Rolla, MO, Joplin, MO, Catoosa, OK, Perry, OK, Oklahoma City, OK, and Weatherford, OK). Overall, we had very positive experience with SpC's. We did not have to wait in line for any of the SpC locations. All the individual SpC's were charging at full speed except one (Normal IL). From one of the other TMC threads, I came across this formula to estimate the expected SpC rate: charging rate (in kW) ~= 120 - battery SOC. During this trip, most of our charging sessions were actually more like 130 - battery SOC (e.g. 110kW at 20% SOC, 80kW at 50% SOC, etc.) Don't get me wrong, I have certainly experience reduced SpC charging rate before, but for this trip the SuperCharging experience was pleasant.

    Having said that, there were about 3 or 4 times when I first connected the SpC cable to the car, the car said the the connection was not secure (orange instead of green light on the charge port) and could not initiate charging session. When I tried unlock the cable (either by hitting the "Unlock" button on the screen or pushing the button on the SpC cable), I had a hard time disconnecting even though the light was white ("unlocked") on the charge port. As a result I would giggle the cable and push it in more while it was locked in the charge port. Eventually the charging session would start (and continue at the expected normal SpC rate). I can't quite understand why this is.

    The trip scenery

    IL - traffic near metro Chicago is as expected, congested and people drive fast and crazy. Downstate IL (well, I-55 to St. Louis) is pretty flat and boring with farm fields. Normal/Bloomington seem to be a decently happening college town. Springfield is a little spread out but seems to have enough entertainment / shopping options for city slickers like us.

    MO - we stayed 2 overnights in St. Louis (on the way out and back)...seems to be a bustling city. The rest of Missouri (I-44 toward Oklahoma) is more "hilly" than the usual Midwestern flat plains. Don't know about the town of Joplin itself, but as I will detail in my review later, I'd recommend avoiding the Joplin SuperCharger if you can.

    OK - speed limits in Oklahoma are high! The Interstates (I-44, I-35, I-40) we drove on were all like 70-80 MPH. It's also generally quite windy (hence tornado territory), making the energy requirement for driving in OK higher than the other 2 states. Also, there were quite a few toll roads in OK (the toll booth on I-44 between Joplin MO and Tulsa OK charged $4.50), so be prepared to have cash and change if you travel through OK. We drove to the Wichita Mountains Wildlife Refuge near Lawton, and we saw longhorns and bisons roaming on the road, which was VERY COOL!

    Overall, we had a great trip! It was our 2nd time taking the Model S as the "road trip" car (we did a Chicago - Detroit trip when we first got the car, but that was much shorter), and the boss (i.e. my wife) agreed to take it for future family road trips (she is generally not a big fan of this car, but that's a different story). I think the fact that we have unlimited free Supercharging helped convince her. We used total of 605.3kWh for the trip, and for the distance of 2,170 miles, we would have had to pay likely over $300 for gas if we took our ICE car.

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  2. Zeromus-X

    Zeromus-X Member

    Apr 10, 2016
    Phoenix, AZ
    The OK toll roads caught me off guard too. I believe there are three segments at $4.50 each. Fortunately I had a $20 in my wallet and they accept cash (some of the newer ones are all electronic -- had to run one in Richmond VA earlier today that had no operators, I'm assuming I'll get something in the mail for it). Your information mirrors mine pretty closely with regards to both the high winds in the midwest and the fact that Joplin's Supercharger location is just sort of awful.
  3. JClu

    JClu Member

    Oct 15, 2016
    So here are my takes on the SuperChargers we used for this trip. I posted reviews on each individual location thread on TMC, but they are copied from my reviews on

    Country Club Hills, IL (post #33)
    Supercharger - Country Club Hills, IL (+ safety concerns)

    Normal, IL (post #182)
    Superchargers in Normal, IL

    Springfield, IL (post #49)
    Tesla Superchargers Springfield Illinois

    St. Charles, MO (post #266)
    Supercharger - St. Charles, MO

    Rolla, MO (post #152)
    Supercharger — Rolla, MO

    Joplin, MO (post #52)
    Supercharger Joplin, Missouri

    Catoosa, OK (post #102)
    Supercharger — Catoosa, OK - Near Tulsa, OK

    Perry, OK (post #174)
    Supercharger - Perry, OK

    Oklahoma City, OK (post #56)
    Supercharger - OKC Oklahoma

    Weatherford, OK (post #27)
    SuperCharger - Weatherford, OK
  4. Skysurfer

    Skysurfer Member

    Aug 14, 2016
    I have a spot on the interstate that does this each time I pass through on AP. Just tap the accelerator and it will resume back to the original speed.

    I was hoping it would learn after passing through nearly every day, but I know to have my foot ready to touch the accelerator when going through that spot now.

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