Possibly Valuable information on elevation changes and roadtrips

[jlucero]

we are embarking on a roadtrip with my family around the western USA for my kids spring break this week and thought it would share some information i have compiled.

i have a 2015 Model S 70D with a max range around 210 right now. we have completed this trip with exclusively tesla superchargers.

we have gone from LA-Vegas-St George-Page-Grand Canyon-Joshua Tree-LA

i have scoured through elevation maps and isolated periods of uphill elevation and isolated downhill elevation. we tried to drive 60mph the whole way. of course driving 80 mph will burn through range. we had 4 medium size people with a trunk full of luggage. weather most of the way nice with no rain.

i have calculated that uphill journies will lose 8.5 miles per 1000 ft and downhill will gain back 5.5 miles.

so as an example....if you drive 50 miles on an uphill stretch that goes up 2000 ft, my car would burn a total of 67 miles (50 miles plus 8.5 miles per 1000 ft). going down that same 2000ft 50 mile journey would burn 39 miles of range (50 miles plus 5.5 gain per 1000 ft).

has anyone else experienced something similar? hope this is helpful!

 

[ewoodrick]

If you are using the Tesla Navigation, it does the elevation calculations for you.

There really is no need to decrease your speed, except to save money and in the few areas in which Superchargers are really far apart. On probably 98% of the routes in the US, there are more chargers than needed.

A strategy surfaced years ago, that works. The faster you go, the faster you can get there. But try charging from 5-50%, not 20-80%. By doing this, you are charging on the best side of the battery charging curve and it makes a big difference. Pull into a 250kW charger at 5% and you can add 100 miles in less than 10 minutes. The next 100 miles will take twice as long (total 3x).

 

[scottf200]

i have calculated that uphill journies will lose 8.5 miles per 1000 ft and downhill will gain back 5.5 miles.

so as an example....if you drive 50 miles on an uphill stretch that goes up 2000 ft, my car would burn a total of 67 miles (50 miles plus 8.5 miles per 1000 ft). going down that same 2000ft 50 mile journey would burn 39 miles of range (50 miles plus 5.5 gain per 1000 ft).

Wow, that was quite an adventure in a 2015 70D! I suspect that your kW flow rate is not that great so patience and charging the "fastest" way was useful. ie. the lower end of the SOC.

I've done a lot of road tripping. I have used ABetterRoutePlanner/ABRP a LOT. I'm curious if you did that for this trip?
As well, in regards, to elevation ABRP should account for that in your preplanning. I'd be very curious if you took one section between points A & B where there was a 2000+ foot change in elevation and mapped it using ABRP from A to B and then try B to A to see how well it shows the efficiency difference.

 

[jlucero]

yea i know the tesla navigation and ABRP do plan the routes for you, but i wasnt sure how accurately it would depict my car so i was worried. we have a gas car too, but its a gas guzzler so my wife and i decided to do alot of planning and research ahead of time in order to save on gas.

what i did was real tedious and a royal pain in the butt. i went on a topography map and mapped out the elevation every few hundred feet, for instance from St George to Kanab. then i made "sections" of uphill, then "sections" of downhill. for instance, lets say A-B was uphill and was 10 miles. i then recorded how many miles of range it actually took me to drive this 10 miles. i then did this for the downhill portion, B-C. i then looked at all uphill journies and all downhill journies to make some conclusions.

 

[scottf200]

yea i know the tesla navigation and ABRP do plan the routes for you, but i wasnt sure how accurately it would depict my car so i was worried. we have a gas car too, but its a gas guzzler so my wife and i decided to do alot of planning and research ahead of time in order to save on gas.

what i did was real tedious and a royal pain in the butt. i went on a topography map and mapped out the elevation every few hundred feet, for instance from St George to Kanab. then i made "sections" of uphill, then "sections" of downhill. for instance, lets say A-B was uphill and was 10 miles. i then recorded how many miles of range it actually took me to drive this 10 miles. i then did this for the downhill portion, B-C. i then looked at all uphill journies and all downhill journies to make some conclusions.

Thanks for your efforts.

a) Now that you have many real-life examples can you do a few of them in ABRP to see if you can duplicate it (by thoughtfully adjusting some parms (Wh/mile base)).
b) ABRP ... generically if you find point A to B where B is 2000+' higher can you do it again from B to A to see the difference

 

[fhteagle]

has anyone else experienced something similar?

Definitely. The uphill section hurts your efficiency more than the same downhill will help you. You won't be able to regen or coast enough to make up for the extra I²R losses on the uphill unless you slow way way way down. Going up and over terrain is going to be less efficient than covering the same distance on flat ground at the same speed. It does hurt less if you slow down significantly going both up and down, though. Fortunately, higher elevation means less air density and drag, but you gotta pay the price to get up here or back up here....

 

[ewoodrick]

yea i know the tesla navigation and ABRP do plan the routes for you, but i wasnt sure how accurately it would depict my car so i was worried. we have a gas car too, but its a gas guzzler so my wife and i decided to do alot of planning and research ahead of time in order to save on gas.

what i did was real tedious and a royal pain in the butt. i went on a topography map and mapped out the elevation every few hundred feet, for instance from St George to Kanab. then i made "sections" of uphill, then "sections" of downhill. for instance, lets say A-B was uphill and was 10 miles. i then recorded how many miles of range it actually took me to drive this 10 miles. i then did this for the downhill portion, B-C. i then looked at all uphill journies and all downhill journies to make some conclusions.

The on-board navigation will include most everything, more than you did, and does it dynamically (including winds) and is historically conservative.

In other words, the on-board will get you there!

 

[EVFamilyGrins]

If you are using the Tesla Navigation, it does the elevation calculations for you.

There really is no need to decrease your speed, except to save money and in the few areas in which Superchargers are really far apart. On probably 98% of the routes in the US, there are more chargers than needed.

A strategy surfaced years ago, that works. The faster you go, the faster you can get there. But try charging from 5-50%, not 20-80%. By doing this, you are charging on the best side of the battery charging curve and it makes a big difference. Pull into a 250kW charger at 5% and you can add 100 miles in less than 10 minutes. The next 100 miles will take twice as long (total 3x).

Unfortunately a 2015 70D maxes out below 125KWh for charging and has a very different charging curve than recent models which can utilize 250KW. Combine that with its short range and that dictates longer and higher SOC charges.

There are some long legs going around Page/Grand Canyon and SCs are sparse.

 

[Phrugal Phan]

There are some long legs going around Page/Grand Canyon and SCs are sparse.

Huh, I just came back from a 3 week visit to AZ and went to Grand Canyon and Page without SC issues. Now going to Monument Valley was a different story - we used an ICE vehicle to go there.

Returning to the East Coast the only problem we ran across was a long stretch on I-40 in Arkansas (or was it Oklahoma?) with no SCs. It was ok, but we ran at 65MPH on that stretch to be safe. If we drove 75+ like everyone else we wouldn't have made it.

 

[ewoodrick]

Huh, I just came back from a 3 week visit to AZ and went to Grand Canyon and Page without SC issues. Now going to Monument Valley was a different story - we used an ICE vehicle to go there.

Returning to the East Coast the only problem we ran across was a long stretch on I-40 in Arkansas (or was it Oklahoma?) with no SCs. It was ok, but we ran at 65MPH on that stretch to be safe. If we drove 75+ like everyone else we wouldn't have made it.

Oklahoma City to Fort Smith AR? That's a long one at 180 miles. I believe that it used to be worse.

But Henryetta, OK is expected to open this year, pretty close to the middle.

That's one of the most well known gaps in the entire US Supercharger Network.