TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Towing to Yosemite

Discussion in 'Model X' started by cmc5dc, Sep 17, 2016.

  1. cmc5dc

    cmc5dc Member

    Joined:
    Feb 27, 2016
    Messages:
    87
    Location:
    Bakersfield, CA
    I'm thinking of towing my 3300 lb Airstream from Bakersfield to Yosemite. The EVTripPlanner estimates a 180.1 mile travel, obviously I would have to supercharge in Fresno which would leave me 61.6 miles to embark up a 4766 foot elevation. I believe I read somewhere that I would lose 10 miles per 1000 feet but what about my load? Any thoughts?
     
  2. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,973
    Location:
    San Mateo, CA
    I have no towing experience, I only want to confirm your estimate that it takes at least an additional 10 miles of range to gain 1,000 ft, and to say that in TMC threads on using the X for towing, real world data shows towing can cut range in half. So I would ballpark it as your 62 mile trip from Fresno to your Yosemite destination could use up at least 154 miles of range. So it seems to me that a 99% charge at the Fresno Supercharger should get you there in your X90D with an adequate safety margin. But I would recommend a near maximum charge to be sure.

    Where are you going to park your Airstream in the Yosemite area?
     
  3. Papafox

    Papafox Active Member

    Joined:
    Jan 12, 2013
    Messages:
    2,571
    #3 Papafox, Sep 17, 2016
    Last edited: Sep 17, 2016
    When I took my Model S to Alaska last summer and had a leg that might use all my available energy, I did experiments ahead of time by driving at different speeds and noting the energy usage. While 65 mph was about 275wh/mi, I could get down to 240wh/mi. by driving slowly (like 40mph!). Thus, I had about 35wh/mi. improvement under my belt if I needed it. Why don't you note the wh/mi. you get at various speeds pulling the Airstream near Bakersfield and see what kind of improvement you get by at regular speed and driving slowly, just in case? Of course driving slowly will only help with aerodynamics and not with the physics of lifting the mass of your Model X and the trailer up thousands of feet. For that you need to do a test on a hill that is something similar to the grade you'll be ascending on the way to Yosemite. You might try various speeds and note the wh/mi. energy usage. Once you have these numbers, you will be able to plan a conservative strategy to get to Yosemite with the trailer.

    There are parts of Interstate 80 over Donner Pass in California where my Model S, which normally is cruising at less than 300wh/mi was using greater than 600wh/mi climbing the steep grade. If I added the extra drag and weight of a trailer my energy usage would have been considerably higher than that, so you might find that doubling your normal energy usage while climbing a steep grade and pulling a trailer might consume considerably more than double your normal energy usage.

    Another resource is the Tesla navigation system. Set your destination into the navigation system and you will see a turn by turn navigation guide to reaching that destination. Now push the "trip" button and you will see at the bottom of the trip window the reserve that Tesla's navigation system thinks you're going to have when you arrive at that destination. It should take altitude gain into account. At first the estimate might be quite inaccurate for towing a trailer up a hill, but as you progress the estimate should become more accurate. Now as you drive, keep an eye on the reserve. If you're heading from 30% to 25% to 20%, then things are clearly not going well, but if it stabilizes at a number above 15%, then you're likely going to arrive with a suitable reserve. The point is to watch the trend of the reserve number. If it is going up or steady at a good number, great. If it's going down towards uncomfortably low numbers, then you have to do some decision-making.

    It is, of course, always a good idea to have a Plan B. If there are no regular charging stations along the way, see if there's an RV park with 50 amp charging along the way, and Plan B would be to pull in there for a quick "helper charge" if you're not happy with the energy in your battery as you approach it. The combination of having a Plan B charging destination and knowing how much benefit you get from various speed options should allow you to avoid ever running out of electricity if you pay attention.

    By the way, do you have one of the new 30 amp adapters that Tesla has just started selling? Some RV Parks don't have 50 amp service and you will need the 30 amp adapter if you want to put in electricity at anything resembling a reasonable rate (it took me 3 days to charge a near empty battery in Alaska on a 110 volt plug).

    Sounds like a fun trip, and you can do your fellow Model X owners a favor by noting your average speed, your average wh/mile energy consumption, and the number of miles of range you used driving from the Fresno SC to Yosemite with the Airstream. The more people report such things, the sooner we'll all be able to plan for such trips more easily. You should have the mileage available to arrive comfortably, but someone with a 60kwh battery might have a more challenging time of it and would really appreciate your posting your energy usage.
     
    • Informative x 1
    • Love x 1
  4. Papafox

    Papafox Active Member

    Joined:
    Jan 12, 2013
    Messages:
    2,571
    #4 Papafox, Sep 17, 2016
    Last edited: Sep 18, 2016
    Here's another way of looking at mileage. I don't know how many watt/hours per mile the Model X's rated range is predicated on, but let's say it is around 300 wh/mi. The range you see on your dashboard is rated range (unless you selected ideal range in your settings). Thus, if you're using 600 wh/mi towing the trailer, your range is half of what you see on the dash, if you're using 900wh/mi, your range is a third of the value seen on the dash, and if you're using a mighty 1200wh/mi your range is only a quarter of what you see on your dash. It's good to have such numbers in mind so that you have a realistic idea of what your range is going to be.

    If you don't want to compute mileage in your head, hit the "Energy" button on your touchscreen and select either the 5 mi., 15 mi., or 30 mi. range. On the left you see your average wh/mi for that 5, 15, or 30 miles of driving you've just completed, and on the right side you see projected range with your remaining energy. If you've just completed 5 miles of steep climbing, hit the 5 mi. choice, and you will have an idea of range remaining if you continue to climb such a steep grade.
     
    • Informative x 1
  5. JimVandegriff

    JimVandegriff Member

    Joined:
    Jun 30, 2015
    Messages:
    247
    Location:
    Trinidad, CA
    We are sitting at 4500 ft in Deer Lodge Montana right now with our 22 ft Airstream Bambi in tow. I echo ecarfan in suggesting that you average watt hours per mile will double approximately thus cutting your range in half.
    One suggestion I have if you do end up plugging in at a commercial campground is to limit your amperage to 80% of the rating of your plug ( 32 amp draw on your 14-50 adapter which can pull 40 amps or 24 amps on your 30 or less.) I've been running into rv park owners who don't like Tesla charging because the Tesla's have blown the camps circuit breakers.
    That said, you should make that trip easily on a full charge. Sounds fun and let us know how it goes.
     
    • Informative x 2
  6. azbob

    azbob Member

    Joined:
    Dec 12, 2016
    Messages:
    32
    Location:
    San Tan Valley, AZ

    Jim, I'd like your opinion as someone who has had considerable time to tow with Model X. Now that the 100D is available, if you were able to decide between the 90D with free supercharging or the 100D without free SC, which would you do? Would the 40 miles of extra range be enough to make you give up free SC?
     
  7. JimVandegriff

    JimVandegriff Member

    Joined:
    Jun 30, 2015
    Messages:
    247
    Location:
    Trinidad, CA
    Great question! I have read that max charge (100%) for the new model X 100D is 295 miles. Illijana and I agree that while this is 35 miles more than the X 90D (260 miles at 100%) and would generally yield about 17 miles more towing distance than the 90D. Is 17 miles worth the cost of supercharging? For us, and the way we travel to campgrounds with hookups, probably not. We would love more range, but it would take a significantly larger battery at this point to negate the free supercharging. Again, this is based on the way we travel, and may not be the same for everyone. If you do lots of boondocking, it might be an attractive option (with a bow to ohmman). Let us know what you decide.
     
  8. TexasEV

    TexasEV Active Member

    Joined:
    Jun 5, 2013
    Messages:
    4,230
    Location:
    Austin, TX
    That won't work for 30A service in most RV parks. The Tesla adapter is NEMA 14-30, which is a dryer outlet, and 30A service in RV parks is usually a TT-30 outlet.

    If the 120V service is 20A, you could use the UMC 5-20 adapter that Tesla sells and pull 16A rather than the 12A you get with the standard 15A adapter. Every little bit helps.
     
  9. BerTX

    BerTX Active Member

    Joined:
    May 2, 2014
    Messages:
    1,135
    Location:
    Texas/Washington
    I haven't seen anyone above reiterate that you also must plan on a significant reduction in speed to achieve the estimate of "half the rated range". It's not half the rated range at 65 mph -- 55 mph will be necessary most of the time, or significantly less with a headwind.
     
    • Like x 1
  10. azbob

    azbob Member

    Joined:
    Dec 12, 2016
    Messages:
    32
    Location:
    San Tan Valley, AZ
    Thank you Jim. I sent the same question to Ohhmann. He said he'd prefer the longer range, to avoid having to charge to 100% at each SC. This would decrease charging time and reduce degradation on the batteries. For what I plan to be doing, I am inclined to agree with him. If I am taking a long road trip, going 300 miles per day vs 100mi /day would take 1/3 the number of overnights in RV parks along the way. Driving through large desert states like AZ, NV, and UT, it would seem beneficial to have greater range. I'm thinking I may drive at night to increase likelihood of more room at SC's to avoid needing to unhook. May also just sleep in airstream at SC location to speed up trip as well. Have you thought of sleeping at SC locations instead of going to an RV park?
     
  11. JimVandegriff

    JimVandegriff Member

    Joined:
    Jun 30, 2015
    Messages:
    247
    Location:
    Trinidad, CA
    When we charge at Supercharger locations we either have to unhook the trailer (not preferred) or pull across several Tesla chargers to charge without unhooking (because most supercharger locations are not set up well for charging with a trailer). In some locations it would be feasible to charge, then move to a spot in the nearby parking lot for sleep, but many lots are not set up to do this easily.
    When Illijana and I started our three month trip, we decided we were inaugurating the "SLOW" travel movement, meaning that we were not going to be doing 300 mile days - primarily because we don't want to be traveling that long in a day anymore (being old and stuff!)
    I would agree with Ohmman about the 100D given the parameters you laid out in the other thread. Can't wait to hear about your adventures!
     
  12. cpa

    cpa Active Member

    Joined:
    May 17, 2014
    Messages:
    1,044
    Location:
    Central Valley
    Here is a suggestion:

    Charge to 75% at Fresno. Then stop two hours later at the new Fish Camp Supercharger and do a full range charge over lunch at the Tenaya Lodge. The Supercharger is about two miles south of the entrance to the park. It is uphill to Chinquapin before you descend into Yosemite Valley. You should have ample charge to reach the Valley, and will have enough to drive around, then perhaps top off at the Majestic/Ahwahnee before making the return trip.

    If you leave via Fresno, you might be able to return to Fresno without stopping at Fish Camp as the return is all downhill after you climb out of the Valley.
     

Share This Page