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
Start a Discussionhttps://teslamotorsclub.com/tmc/tags/

Sub-300wh/mile drafting

Discussion in 'Model X' started by mal_tsla, Mar 19, 2017.

Tags:
  1. mal_tsla

    mal_tsla Member

    Joined:
    Sep 29, 2016
    Messages:
    338
    Location:
    Austin, TX
    IMG_7365.JPG
    Had a bit of a range crisis on our last trip after a planned charge location was ICEd with no practical alternatives.

    Ended up drafting a FedEx semi pulling two trailers for about 15 miles at 70mph and less than 300wh/mile in an X90D. Sat about two car lengths behind ready to take action and let him air-tow us to the next charger. Felt nervous being so close, but it seemed the best option. It was weird watching the trip meter go up in destination % even as we covered miles.

    In the end, we hooked up at the next supercharger with 8 miles indicated remaining. Phew!
     
    • Informative x 1
    • Like x 1
    • Funny x 1
  2. BigMskiman

    BigMskiman Member

    Joined:
    Mar 14, 2016
    Messages:
    629
    Location:
    Pleasanton
    I had to do same with wife on board, and it was not a good introduction for her to MX range anxiety. On-screen warnings about low battery and where to go, were taken seriously, so the tail-gate truck approach worked well. Got to Dublin SC with 4 miles to spare.
     
    • Helpful x 1
    • Like x 1
  3. mal_tsla

    mal_tsla Member

    Joined:
    Sep 29, 2016
    Messages:
    338
    Location:
    Austin, TX
    We actually had a backup plan to stop at a supposed Tesla connector midway to the supercharger. However, once we were drafting the truck, comsumption was so low that it seemed a better decision to brave it to the SC than risk arriving at the other charge site only to find it broken or blocked.
     
  4. wcfinvader

    wcfinvader Member

    Joined:
    Jul 2, 2014
    Messages:
    368
    Location:
    Aurora, NE
    I work for same company pulling doubles. I know and completely understand your reason for doing this just throwing out the perspective of the FedEx driver.

    I occasionally get cars tailgating me. I give them a couple miles to pass or exit. If the stay back there I slow down. Once I had to slow all the way down to 40mph before a tailgater passed me. I don't do this to be a prick. I do this because as a truck driver we are held to higher standards by DOT and the company. Personal drivers have only at fault or not at fault accidents. We have that along with Preventable accidents, Unpreventable accidents, and incidents. Say I blow a tire (we have 18 that can blow at any time for any reason) and said tire debris hits you because you were tailgating me. I get a not at fault preventable accident on my record, lose my safety bonus, and get disqualified from truck driving championship for a year. There are any number of things that can go wrong in a semi. Ever notice a truck have his trailer lights completely out while he was driving at night? Most likely when the driver pretripped the truck they were on but during the drive developed a short. Luckily FedEx has since installed lights on the side in the view of the driver to tell this but the majority of semis don't have this feature.

    This all might seem severe and it most likely is the reason for a large driver shortage in the trucking industry but it is a necessary means to keep you all safe as well as ourselves. Don't make a habit of tailgating a semi. If you do tailgate one though and he slows down now you know the reason why though.

    Be safe out there. I myself have seen way too many accidents (a few fatal). Last one I saw was a fatal where a car rear ended a semi at high speed. It went clear under and struck the axles. The occupant was decapitated.
     
    • Informative x 11
    • Like x 1
  5. mal_tsla

    mal_tsla Member

    Joined:
    Sep 29, 2016
    Messages:
    338
    Location:
    Austin, TX
    Totally get that and a major reason why the whole ordeal was stressful.

    I certainly wasn't recommending anyone do this, it's not fun and it is risky.

    That said, life is managing risks.
     
  6. FlatSix911

    FlatSix911 918 Hybrid

    Joined:
    Jun 15, 2015
    Messages:
    4,050
    Location:
    Silicon Valley
    Next time ... a better way to manage risk is to slow down to 45-55 mph to achieve max range on the way to the next SC :cool:

    driving-range-for-the-model-s-family-chart1.png
     
    • Like x 4
    • Informative x 2
  7. wcfinvader

    wcfinvader Member

    Joined:
    Jul 2, 2014
    Messages:
    368
    Location:
    Aurora, NE
    Completely agree with this solution. I was able to do 280 miles on one charge once doing 50-55mph the entire way. Beat rated range. Best solution is to always slow doubt when in doubt with range.
     
  8. mal_tsla

    mal_tsla Member

    Joined:
    Sep 29, 2016
    Messages:
    338
    Location:
    Austin, TX
    I did. 40 mph or less was required on roads with other cars traveling 75-80mph. Not safer.
     
  9. BerTX

    BerTX Active Member

    Joined:
    May 2, 2014
    Messages:
    1,985
    Location:
    Texas/Washington
    Thanks! Brings a whole new light on this topic for me.

    I hate to start a string of somewhat off-topic discussion, but for me a lot of time is spent sharing the highway with trucks. The more I know, the more we can help each other.

    As I was passing a truck the other day, one of his rear tires started shredding and was about to blow. I could either be behind him or in front, and having the ability, I quickly passed him. 1) how serious is losing a tire for a truck? 2) Should I try to let the driver know? If so, how?
     
    • Like x 1
  10. wcfinvader

    wcfinvader Member

    Joined:
    Jul 2, 2014
    Messages:
    368
    Location:
    Aurora, NE
    If it's a Steer tire then get way back. That's my number one fear is a blowout of a Steer tire. Many truckers are killed by that because when it goes the truck drops and momentum carries the semi either to the left if it's a driver's side steer blowout or to the right if it's a passenger side blowout. When that happens we are trained to keep on the accelerator and get it straight before we slow to a stop. The worst thing we can do (and what many truckers make the mistake of doing) is hit the brakes. If a trucker hits the brakes in that situation he will roll the entire semi and that's the part the results in the loss of many truckers. Instinct is to brake but overcoming the instinct is something that's required to make it out of that situation.

    The vast majority of the time it will be a trailer tire blowout and they blow with such force that they can kill a motorcyclist if the debris strikes them (mythbusters tested this myth). Best thing to do is to slow down and wait for it to blow. Don't run over the debris either. I blew a dolly tire last fall overnight and 30 seconds after I blew it a car ran over the debris. It punctured his oil pan and slashed both passenger side tires. No matter how heavy a load is we feel it when we blow a tire. A couple years ago I blew a tire on the rear trailer. Both trailers were empty and the force sent the trailer into the passing lane enough that had there been a car there then they would have struck.

    The big reason trailer tires are most common to blow is mainly because they tend to be checked much less often. Pretrips are don't but flaws in trailer tires can be very hard for a driver to find. Also trailer tires come under the most stress because of the weight they have constantly on them. Drive Tires (rear tires of the Tractor) get checked multiple times a day and flaws are easier to find because you can disconnect from the trailer to see the entire tire. Truckers also force companies to get them replace prematurely because of the risk of hydroplaning.

    If we lose one tire on a trailer or dolly we can drive without it depending on the weight that is in the trailer. I had to do this once. Road Service couldn't find me and after waiting a hour I was allowed to try to make it to the company shop. I drove 10 miles with a blown tire but only did 45mph tops. If you've ever seen a truck with two blown tires on the same axle and side it's because he tried driving with a blowout while he had too much weight on his trailer.

    Hope that helps.
     
    • Informative x 6

Share This Page