"Zero" means "Zero" - Caution about Vegas to LA trip!

[SwedishAdvocate]

…/ there is a belief that there is a 20 mile reserve beyond zero. This is false. 0 on the dash means 0! […

I too have been 4 miles past zero as you can see here: /…

The OP has a 60 kWh... :wink:

I have a feeling there’s a difference between the reserve past 0 in a 60 as compared to the reserve past 0 in a 85.

 

[brianman]

there is a belief that there is a 20 mile reserve beyond zero.

My recollection is that the number was "__ rated miles" where the __ is lower than 20. I forget the exact number.

I have no idea how __ varies across 40, 60 and 85 kWh packs.

 

[TonyWilliams]

Source? Would also be good if the Nav calculated the total elevation change on a routed trip from A to B, and gave hints about whether the rated range was an overestimate (net going "uphill") or an underestimate (net going "downhill")

You can try the app that was written for the Nissan LEAF based on my range chart called "LEAF Energy". The part that a Tesla driver might like is that you can input your starting point and destination, and it will calculate the elevation gain and give a Google route.

It will also import temperature, but not wind. Certainly, it could be written for all the Tesla products. Let me know what you think.

 

[wts13]

Possibly going to make this trip in January to/from CES so will definitely plan to range charge all the way on the way back. Probably start off going 60mph and then speed up once things are looking good.

 

[jerry33]

+1 Always have a back up plan. No matter where I plan on charging on a roadtrip (and Roadsters don't have the luxury of superchargers), I always know what my backup charging plan is 'just in case'). I even print out the locations, in the event that there is no cell phone coverage at the point I need it the most.

Me too. I create a spreadsheet with planned stops, distance, charge remaining both ways, and amount to capture during charge. At the bottom there are two alternatives to each charge stop. If you are going to travel X miles, you will be charging for X hours regardless of whether you stop once, twice, or three times, so there's no real incentive to try to get the most out of one charge. I try to make the stops as close to 150 miles apart as possible.

Example:

Home: Full range charge
Stop 1: 125 miles, balance 140, Charge to 250
Stop 2: 205 miles, balance 45 miles, Charge to 210
Stop 3: 150 miles, balance 60 miles, Charge to 200
Dest: 140 miles, balance 60 miles

I typically end up with more balance than the calculated amount (typically 80 miles).

 

[Mark Petersen]

One trick I used on my last trip, was to enter the destination for the charger in the navigation, and the show the energy screen at the same time
At the start of the trip I look at the GPS range to destination and compare that to ideal remaining range
And while I'm driving look at the projected average range and ideal remaining range, if these 2 drop faster that the gps remaining range, I slow down

 

[wycolo]

Siri voice: "Inadequate response! You need to drop to 35 mph under these conditions. Put on Flashers. If posted minimum speed is 40 then set cruise control at 36 mph, close enough."
--

 

[Cottonwood]

Me too. I create a spreadsheet with planned stops, distance, charge remaining both ways, and amount to capture during charge. At the bottom there are two alternatives to each charge stop. If you are going to travel X miles, you will be charging for X hours regardless of whether you stop once, twice, or three times, so there's no real incentive to try to get the most out of one charge. I try to make the stops as close to 150 miles apart as possible.

Home: Full range charge
Stop 1: 125 miles, balance 140, Charge to 250
Stop 2: 205 miles, balance 45 miles, Charge to 210
Stop 3: 150 miles, balance 60 miles, Charge to 200
Dest: 140 miles, balance 60 miles

For the pilots in the group, long road trips are much like cross country flights, make sure that you have enough fuel (charge) with margin to make your destination, and have alternates if your planning starts getting close. For the pilot, carrying lots of excess fuel, means slower climbs, and slightly slower speeds; for the EV owner, it means spending longer at an intermediate charging locations, making the whole trip take longer. The big difference is that the first leg can go out with full charge (fuel) because there is no cost to a full, overnight charge.

Have fun Road Tripping!!!

 

[Gizmotoy]

You can try the app that was written for the Nissan LEAF based on my range chart called "LEAF Energy". The part that a Tesla driver might like is that you can input your starting point and destination, and it will calculate the elevation gain and give a Google route.
It will also import temperature, but not wind. Certainly, it could be written for all the Tesla products. Let me know what you think.

You could use EV Trip Planner from the dash (no navigation integration I suspect, though). Calculates routes using elevation, and provides means to correct for wind (manually, unfortunately, but it should be relatively easy if you're going in one direction). Seems pretty decent.

http://evtripplanner.com/planner/carview_beta/?id=kxl

 

[brianman]

Regarding spreadsheets, I probably should have published this a bit back.

It's an old version so keep in mind that you should double-check the distance data. The formulae were fine, just some of the data points of actual distance were wrong and I just never updated this copy.

 

[vfx]

I've done the LV trip in the Roadster and two things helped me on the horrendously windy way back. I found a real big truck going closer to 55- 60 and just tucked behind them for 40 miles. There was a huge slowing in miles dropped. As others mentioned, the various apps would have told you about the alternate places you could have stopped. Big towns have Nissan and Chevy dealers that all have plugs.

 

[simplesolar]

I've done the same when low on power. I tailed behind a big rig driving 40-50 miles and my usage went below 300wh/mi and I was able to stretch those miles.

I've done the LV trip in the Roadster and two things helped me on the horrendously windy way back. I found a real big truck going closer to 55- 60 and just tucked behind them for 40 miles. There was a huge slowing in miles dropped. As others mentioned, the various apps would have told you about the alternate places you could have stopped. Big towns have Nissan and Chevy dealers that all have plugs.

 

[yobigd20]

As I was reading this thread I was going to reply and say that drafting significantly reduces kWh/mile but the above two posts beat me to it.

I don't really recommend doing it as it's kinda dangerous tailgating (by definition it means following so close that there's no guarantee you can stop in time to avoid a collision). However, in this situation it would actually get you out of that tight spot.

I have actually been experimenting with this on the New Jersey Turnpike and I can visually watch my wh/mile drop from 350 to 230-250. It's a huuuuge drop, the closer you draft the bigger the drop.

Besides it being dangerous though, the other downside is you'll probably get dinged up from rocks and stuff.

But if you did this continuously, you probably could do 280-300 miles in a 60 or over 400-450 in an 85.

(If the model S had adaptive cruise control with radar to keep distance constant, I'd love to set it to 10ft behind a big rig and see what my watts/mile would drop to lol)

 

[Benjamin Brooks]

(If the model S had adaptive cruise control with radar to keep distance constant, I'd love to set it to 10ft behind a big rig and see what my watts/mile would drop to lol)

Would be a cool feature... makes one think maybe this drafting energy savings is maybe another big reason why Tesla didn't design in ACC? Hmmmm

 

[wts13]

I get that hyper-milling is cool and all...but risking my safety (and paint) to save a few minutes of charging somewhere along the way? No thanks.

 

[brianman]

kinda dangerous tailgating (by definition it means following so close that there's no guarantee you can stop in time to avoid a collision). However, in this situation it would actually get you out of that tight spot.

Drafting has degrees. Not all drafting is tailgating. When the lead car is an 18 wheeler with a nice box shape, there's not enough benefit to tailgating; a reasonable distance is still a significant range win.

 

[stopcrazypp]

the other downside is you'll probably get dinged up from rocks and stuff.

I think this is the biggest negative. Like brian says though, you don't necessarily have to tailgate to get benefits though.

 

[Puyallup Bill]

(If the model S had adaptive cruise control with radar to keep distance constant, I'd love to set it to 10ft behind a big rig and see what my watts/mile would drop to lol)

Oh, wow! Ten feet? I couldn't handle that.

 

[liuping]

Drafting has degrees. Not all drafting is tailgating. When the lead car is an 18 wheeler with a nice box shape, there's not enough benefit to tailgating; a reasonable distance is still a significant range win.

Tailgate drafting (10ft) is dangerous and I would never recomand doing that at highway speeds.

However, according to the Myth Busters(MythBusters (2007 season) - Wikipedia, the free encyclopedia), drafting at 50ft behind a big rig gives you a 20% increase in mileage. Even at 100ft, you get still get a 11% boost.

100 ft is pretty reasonable, and 11% is an extra 20+ mile range, possibly more in a strong head wind scenario.

 

[TeslaSinHR]

I've gone down to zero (see my avatar) but didn't get stranded. One night, I thought I had plenty of range to make the 40 mile drive home on I-84 so I decided to drive it REALLY, REALLY fast. I noticed how quickly my range was dropping but decided to push it anyway. When my rated range was about equal to how far I have left to go I slowed down to 50 mph for the rest of the trip. My range was zero on the off-ramp from the freeway and luckily I made it all the way to my house (which wasn't far).

As others have stated - when in doubt, slow down. 55 mph feels painfully slow but it is better than being stranded at the side of the road waiting for a flatbed truck.