It's not time-efficient to slow down; the car is using power at a slower rate than the SC can inject it. (This sentence is NOT true for L2 charging.) There's always a benefit in drafting, moderate temps, and a tailwind.
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The factors we can control are straight forward.
Always arrive as with low as possible (within reason) state of charge to take advantage of the faster charge rate at Superchargers.
Drive fast (not illegally) because the Supercharger can recharge faster than you can drive, thus driving faster and using more energy is overall faster than trying to drive conservatively. (I have tested this many times)
Picking the right time to avoid traffic on roads that are known to get lots of traffic.
Hopefully with Tesla's support, keeping the Superchargers free/open when we arrive so there is no delay at SC or slow charge rate.
Get an ICE car driver go ahead of us warning us of hazards on the road, speed traps, accidents, ...
A few spare wheels that can quickly be swapped when someone has a flat.
Get Starbucks to sponsor us with coffee
I'm not opposed to doing it as one continuous run vs stopping and sleeping while stopping the clock. But doing it as one run makes things more complicated and requires two drivers per car. By taking breaks we can time it better and avoid traffic better. We could drive more at night, less during the day.
Always arrive as with low as possible (within reason) state of charge to take advantage of the faster charge rate at Superchargers.
Drive fast (not illegally) because the Supercharger can recharge faster than you can drive, thus driving faster and using more energy is overall faster than trying to drive conservatively. (I have tested this many times)
Picking the right time to avoid traffic on roads that are known to get lots of traffic.
Hopefully with Tesla's support, keeping the Superchargers free/open when we arrive so there is no delay at SC or slow charge rate.
Get an ICE car driver go ahead of us warning us of hazards on the road, speed traps, accidents, ...
A few spare wheels that can quickly be swapped when someone has a flat.
Get Starbucks to sponsor us with coffee
I'm not opposed to doing it as one continuous run vs stopping and sleeping while stopping the clock. But doing it as one run makes things more complicated and requires two drivers per car. By taking breaks we can time it better and avoid traffic better. We could drive more at night, less during the day.
This gets repeated on these forums, and it sounds good (meaning it's the answer we want to hear), but I don't know if it has been actually tested much. Sure, the logic sounds good and the math seems to work out, but I'm not entirely convinced. Maybe it's from so many years of slowing down to save fuel. It reminds me of the diesel pickup owners who will swear up and down that they get the same fuel economy at 85 mph as at 65 mph. Ask for their data, and they can't produce it. It's what they have heard, and it's what they want to believe, so that becomes their truth.
Maybe if, on this trip, there are those who want to go fast and those who want to go the speed limit, two groups can set out to put it to the test!
One issue you are going to have in traveling in a caravan AND trying to set any kind of record, is that you will all arrive at the Supercharger at the same time. That won't work. Several of those Supercharger facilities are small. Everybody pulls into a stall and starts charging, and it will be slow because of loading on the charger. Plus, some cars will have to wait while others charge, thus doubling their charge time. Are the first group going to wait while everybody gets charged? Doesn't sound conducive to record setting. Or, as the first group gets done, do they leave? Doesn't sound very social.
chickensevil
Active Member
My approval of this is that I love that you are timing it to join us on our east coast get together! Like those who went west for your annual meetup. I am really happy to see you guys show up for this and will finally get to meet some of you west coast guys (and maybe a few more from the mid-west).
I understand how this may seem counter intuitive but you have to throw out what we have been conditioned with ICE cars because the point isn't about fuel efficiency (which applies to both EV and ICE still) but how quickly can you refuel. With gas, it is not an issue since it takes a few minutes to refill an empty gas tank. Not the same with Superchargers. Charging from a lower SOC will dump juice into the battery must faster initially then tapper off. It takes about an hour to fully charge a MS. Unless you can drive faster than 200+ miles/per hour, a SC is going to refuel you faster than you can use it up.
For example, I've driven up the 101 from SoCal to NorCal several times now. On my last trip, I decided to ignore efficiency and just focused on hitting every SC, charging enough to get to the next SC with a comfortable buffer and then going 70-75 mph. I was definitely not fuel efficient but I only spent about 30 minutes or less at each SC and made it back home faster than driving slower.
Yes, I can see that the difference between driving 70 mph and 80 mph between Superchargers is about 15 minutes. If the difference in the amount of time it takes to charge sufficiently to drive 80 on the next leg vs. the time required to charge sufficiently to drive 70 is less than or equal to 15 minutes, then I get it.
It just seems that the increased speed is causing the drag to increase exponentially, causing a disproportionately high usage rate. The increased amount of charge required, both due to the increase in required stored power to make the next leg at the higher speed and the fact that the battery charges slower as the SOC increases, will significantly increase charge time.
Forgive me, I'm not lucky enough to have a Tesla to play with yet. It just seems like multiple factors working against this fast-driving concept being accurate. I have read of those who have tried it successfully, but I have trouble wrapping my brain around it. The flow-out-while-driving being slower than the flow-in-while-charging sounds reasonable on the surface to me but it's more of a mantra than a rule.
I guess my prescription is to get a Tesla and do some research for myself. :biggrin:
chickensevil
Active Member
It would specifically factor into how far apart the chargers are as well. Going from say Savannah, GA to St Augustine, FL (174 miles) might actually be better to drive at or below the speed limit since in good weather you will need a solid 190 miles of range just to make it there going 70MPH (the speed limit).
On shorter legs, say Newark, DE to Hamilton, NJ (73 Miles) you would easily be able to take the NJ Turnpike going 90MPH and it would be better than driving the speed limit due to the short hop.
But then, considering instead to skip Hamilton and go to Edison, NJ (104 Miles) would it be better to skip? At what speed given the choices and routing would be the most optimal? Likely 104 miles is low enough that you could put about 140/150 miles on the dial and go 85-90MPH on the turnpike and it will work out the best for you all around... So then at what distance does speed vs recharge time take over? I do think that when you consider the possibility of skipping a charger that makes a decent dent in your calculations as well. Because it takes a good 5 minutes to detour off the interstate to the charging site and get plugged in. So 10 minutes round trip... that a skip will save you.
So there are multiple factors that I don't think it is a simple answer either way. You would need to know your route (terrain, weather, etc), all available stops (not that you will necessarily take them all), and the time to recharge to a given SOC %. Plug all that into a formula and have it spit out your "best" speed and stops.
Let me start by asking those intending to join us to PM me so the planning may begin.
I'm in contact with Guinness to get the various records (official and unofficial) that can be broken or made. The obvious one is time spent charging (this is the one Tesla did). As we crete the rules for the event a few are popping up from some of you who have contacted me so I'll answer them here.
ALL CHARING (save for the first leg) will be done ON THE CLOCK. And counted toward travel time.
IF we stop at pre-determined hotels, Hotels with Super Chargers will be given preference.
Meeting up with the East Coasters should be a blast. Yes, Im hoping this becomes an annual thing but lets get the first one going first
I'm in contact with Guinness to get the various records (official and unofficial) that can be broken or made. The obvious one is time spent charging (this is the one Tesla did). As we crete the rules for the event a few are popping up from some of you who have contacted me so I'll answer them here.
ALL CHARING (save for the first leg) will be done ON THE CLOCK. And counted toward travel time.
IF we stop at pre-determined hotels, Hotels with Super Chargers will be given preference.
Meeting up with the East Coasters should be a blast. Yes, Im hoping this becomes an annual thing but lets get the first one going first
By the way, as well as this raising awareness for EV's, This will also be a CHARITY RALLY to benefit Batten Disease research in memory of my 6 year old nephew Seth, who passed away 2 weeks ago.
Trust me, I have tried it many times and it is overall faster to drive as fast as you can and charge more at Superchargers. Here is some very simple numbers:
driving 100 miles at 65 takes 91 minutes and uses 31 kWh. To recharge that a Supercharger (doing 100kW) needs 18.6 minutes. Total time: 109.6 min
driving 100 miles at 85 takes 70 minutes and uses 43 kWh. To recharge that a Supercharger (doing 100kW) needs 25.8 minutes. Total time: 95.8 min
You spend 7 more minutes at the charger, but you saved 21 minutes on the drive. Pretty straight forward.
There you go! Much easier to trust you when you put numbers up there. From others, I was only getting the "Trust me" part...
Thanks!
jcadman22
Tesla Owners Club Maryland
I just discovered this thread thanks to Chickensevil and I echo his sentiment. Looking forward to meeting everyone in Maryland! Good luck on the coast-to-coast drive - I can't wait to hear the stories!
Bighorn
Top Supercharger
You can't do a straight line approximation of charging speed since it tapers. IIRC, folks who've looked at the calculation based on real charging rates based on SOC found an ideal driving speed somewhere in the mid 80s. The theoretical fastest long distance travel speed is approximately 55 MPH, so I don't think we need to worry about bragging bringing any sort of unwanted attention from the authorities. Of course you're going to run into problems with more than two cars arriving at a 4 pedestal SC.
I brought this up earlier, and apparently they are not going to worry about it. I think it is more of a social event than a real attempt to set any records. :biggrin:
I think they will get the speed record in the bag even without optimization, St. Charles, MO is under construction as of a week ago which allows for a much quicker route. And 2 days ago Effingham, IL got a permit, if that station goes up in time, it would shave a bit more time.
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