Question about onboard trip planner

[Tacoday22]

Hi,

I've been mulling over an EV purchase for a month. After a test drive of model S and catching up with EV education on this board and hours of youtube contents, it's becoming more evident that other OEMs have a lot to catch up to Tesla, especially when it comes to its ability to provide support for road trip use cases.

A question for everyone here who have done challenging roadtrips: how reliable were the range information on onboard navigation when vehicle was put through roadtrip uses that involved:

- Adverse weather conditions
- Travel that involved bike racks or roof mounted storages
- Elevation gain

 

[jlv1]

I still preplan all my long (>300 mile) trips with ABetterRoutePlanner.com just so I get some general idea on what options I have for charging. It can take into account elevation, headwind, and weather conditions. Here in the north east we have really good SuperCharger coverage, so often on a long trip we are skipping several SCs before we stop to charge, and ABRP helps me pick and chose as I make a plan for the trip.

But as they say, no plan survives contact with the enemy, and this is where the onboard navigation shines.

The best example is our 450 mile trip to Buffalo last Christmas. It started out with freezing rain and turning into a heavy snow. The car got coated enough with ice that the AutoPilot radar was obstructed and AP disabled itself. We had no worries; we had to make an extra stop SuperCharging but never felt like we'd never reach our destination.

 

[ewoodrick]

The onboard computer doesn't compensate for any of those factors. While of those are indeed factors that determine range, most folks don't worry about them that much.

As you are purchasing your first EV, range anxiety is commonly a big deal. To a great degree, it severely overrated, your worry about range.

I had the 88 mile 2015 Leaf. There were indeed trips that it could make and trips that would have been tough. For many of those, there were charging options available, it just added time.

But with the 2018 Leaf at 150+ miles, it seems to be able to go forever. It becomes a car that can handle medium distance trips (100-300 mile) without much difficulty.

When you hit the 250+ miles of Teslas, it isn't much of a problem anymore. Sure, I think about it, I check it, but I don't worry about it. We recently took a trip from Atlanta to Jackson MS, to Destin FL and up to Cherokee NC, 1600 miles, and had no issues with charging. Only about half of the roads were Interstates and we spent $36 on charging.

We're at the point where we are a two EV family and have no ICE vehicles. I have no issues being able to travel just about anywhere. When I'm not on a road trip, life is so much easier. I don't have to spend time at a gas station once a week. I don't get gas spilled on me. I don't worry about oil changes, I just drive the car. When charging at home, the car has effectively unlimited distance around town, I never run out, because it always fills up overnight.

But to directly answer your question, while those items do impact the distance, speed is probably the number one killer of range. While the onboard computer doesn't really compensate for speed, it will tel you if your current consumption rate is too high to reach your next destination and will tell you to slow down. The same things should happen with any of the factors that you list, just slow down to increase/compensate for needed efficiency.

 

[agtdDelirium]

You are correct that Tesla is the only viable EV right now for supporting long distance road trips. The supercharger network will keep Tesla in the lead in this regards for several more years.

I just recently completed a 2000 mile round trip from Colorado to the West Coast. The onboard trip computer can certainly be trusted, and I find is usually slightly on the conservative side in energy usage, especially with altitude changes. You would have to do something stupid to run out of energy in this car. I find very little practical difference in use compared to an ICE vehicle. If you push your luck driving that gas gauge on an ICE vehicle below "E", eventually you will get caught and end up on the side of the road with your thumb out. Same factors are in play driving a Tesla. Only difference is you need to do some trip planning before you depart, since your "fuel" stations are more dispersed. I personally always keep a buffer of about 15% battery power before setting out on a leg of a trip. Usually I end with a few percent more than predicted, but many factors can influence this.

The trip computer does take into effect altitude gain/loss. It does not take into effect your lead foot tendencies which can have a big impact. If you are going to drive 80 mph on a 60 mph highway, you will burn through battery charge exponentially faster. If you are ever running close to reaching a destination with available charge, you can just slow down. The range quoted for Tesla's is usually that for driving 60 mph. That same 300 mile range becomes 450-500+ if you reduce speed to 30 mph. This is a big safety "reserve" if you are ever cutting it close.

Other adverse driving conditions will reduce range. Temperature has a potential significant hit on range, especially if running the heater in the car. Heavy rain, slush, or anything else that increases rolling resistance impacts electric vehicle range more than ICE vehicle range. But planning with an additional 10-15% buffer easily corrects for that. Same for roof racks/bike racks. They will reduce range, but it all is dependent upon the degree of resistance, magnified exponentially by speed of travel. Once you own the vehicle, you quickly begin to learn what that impact is and just plan accordingly.

Range anxiety is really only for those thinking about purchasing an EV. Once you own one, you easily become comfortable with its use. I find the planning for long trips very enjoyable. I am a private pilot as well, and the planning is very similar to flying small aircraft. You have to plan your route, and pick where you are going to refuel before you ever leave the driveway.

Another good website is www.evtripplanner.com

 

[Tacoday22]

Does the onboard system dynamically adjust range information based on the trip condition? For example, the presence of a bike rack will have a fixed reduction of range and it should be easy for the system to adjust its range information accordingly. Additionally, does the system override driver pedal input (as in forcefully optimizing acceleration and limiting top speed) when it determines that range is jeopardized?

 

[dgpcolorado]

Does the onboard system dynamically adjust range information based on the trip condition? For example, the presence of a bike rack will have a fixed reduction of range and it should be easy for the system to adjust its range information accordingly.

Sort of. Please understand that the "miles of range" displayed on the dash is "rated miles" and is an energy gauge, NOT an estimate of how far the car can go, except under EPA conditions. However, the car DOES update the %battery-at-the-destination estimate in real time as you drive, when using navigation. In your bike rack case, the car would have much higher than expected energy use per mile and the %battery-at-the-destination estimate would drop as you drive, no surprise since it is based on ordinary driving conditions. If it gets too low, the car will warn you to slow down and recommend a speed. When driving with a bike rack, or in adverse conditions, it is best to charge to a higher than usual "buffer" — the estimated % charge remaining at the destination. For a typical trip in good conditions you might use 15% or 20% for a buffer. With a bike rack you might want to use 30% or 40% until you get used to the actual energy consumption.

The amount of buffer needed depends a lot on the distance of the trip leg. For a short trip leg of 50 to 80 miles, a smaller buffer is needed than a trip leg of 150 miles because you will be experiencing the increased energy consumption for a longer time in the latter case.

Road trip advice: when the energy at destination is dropping it is helpful to slow down right away, rather than wait until you are closer to your destination and see that you aren't going to make it. That way you can slow down a little for a long time rather than have to drive 50 mph when the speed limit is 80 (as I had to do when faced with a strong headwind, because I didn't slow down soon enough). If you slow down until the %battery-at-the-destination estimate stabilizes, that gives you an idea of the speed you should drive. The exception is when you know from experience that you will make it to your destination with a safe battery level. Trust me, you will develop a "feel" for this in time.

Additionally, does the system override driver pedal input (as in forcefully optimizing acceleration and limiting top speed) when it determines that range is jeopardized?

No, the system does not force you to drive conservatively if energy is limiting unless you get to near zero, which should NEVER happen if you have been paying attention all along. One exception: in cold weather the battery power (acceleration/regen) is limited to protect the battery (not to conserve energy for a trip).

One more thing. The trip planner does take into account elevation changes (hills) but it does not adjust for altitude. What's the difference? Hills require energy to go up and give back energy when going down (regen). Driving at high altitude causes less aerodynamic drag — fewer air molecules to push out of the way — and leads to lower energy use per mile, other conditions being equal. Those of us who drive at high altitude tend to get better range than the car estimates, as compared those driving at sea level. FWIW.


-experienced road warrior

 

[animorph]

The nav will take elevation into account at all times. It also assumes an average driving speed for each road.

Weather and car loading/attachments I believe are incorporated by the nav only by using your efficiency over the last 30 miles. So if the next leg of your trip has roughly the same conditions as the last 30 miles the nav should be fairly accurate. As you travel, it will update its estimate and your charge remaining at the destination will become more accurate.

The only time the nav was inaccurate in estimating the charge required between Superchargers during our last long trip was when it started raining, heavily, while we were stopped at a Supercharger. We charged quite a bit more than the nav thought we needed, since we new the rain would be a problem. After driving for a bit in the rain, the nav was reducing its estimate of our charge remaining at the destination, as it saw our efficiency drop in the rain. That let us know we had to slow down a few MPH in order to maintain about 10% at the destination. So, if conditions are stable and the same as your last 30 miles you should be able to trust the nav. If things are changing you may want to help it along a bit.

 

[maximizese]

I'm about to take my first road-trip in my wife's MS85. We're going from Orange County, Ca to Calistoga, Ca on a Sunday morning (it'll be interesting to see how crowded the SC lots will be). According to the onboard computer, the trip will be about 9.75hrs including 2hrs of SC charging time. However, using evtripplanner.com I can punch in extra assumptions such as average speed, payload, HVAC usage, range buffer, etc to get a more accurate picture. By adding a 4th SC stop along the way, I can effectively cut my trip time down to 8.5hrs and save about 15 minutes of charging time. This is possible because our cars recharge much faster on a more depleted battery and slows down considerably as the battery replenishes past 40%. Generally, it doesn't seem worth my time or others waiting to charge beyond 80%.

So I set my range buffer for 10% (or 21 rated miles) and EVTP calculates the estimated time I need to charge at each SC lot make it to the next SC with ~21 miles of headroom. The other interesting assumption is vehicle speed. Many of us have noticed that the rated miles on our cluster display are rarely actualized in the real-world. According to EVTP, it's implied that the rated miles assumes an average of 58mph cruising speed; which might be arbitratary average of city/hwy speeds). Tinkering with the numbers I found the following:

An average cruising speed of 68mph would result in a 15% reduction in rated miles.
An average cruising speed of 80mph would result in a 30% reduction in rated miles.

In other words if you're showing 100 rated miles on your cluster and you're driving an average 80mph, expect to get no more than 70 miles of actual distance traveled. I'm looking forward to testing a few theories along this road trip and I'm confident that I won't unexpectedly need to slow down for Wh/mi-sake.

*I should note that charging times assume you can get the full potential charging rate without sharing a paired SC.

 

[OTARon]

This is a link to my story I posted about buying my Pre owned, and the 1550 road trip home. With a trip from Vegas to WA via the CA coast, we saw wind, rain and a few step climbs. Something like 11 stops for charging and the car directed us to each stop. My ONE real complaint is you can't put in way points in the nav system, Las Vegas to WA via Gilroy Ca, San Fran Ca, Eureka Ca, Then WA. The systems has a start and stop they it routs you the fastest way, you have to break up long trips if you want to go your own way.

As your driving you can have SC's show up on your Nav, so if your running light, they Nav will direct you to stop sooner. I had that happen as we drove into a head wind, we soon didn't have the juice to make it to 1 charger and had to stop sooner.

I look forward to more long trips in my TMS 90D soon

Preowned Purchase story and the Happy ending

 

[quickstrike12]

I'm about to take my first road-trip in my wife's MS85. We're going from Orange County, Ca to Calistoga, Ca on a Sunday morning (it'll be interesting to see how crowded the SC lots will be). According to the onboard computer, the trip will be about 9.75hrs including 2hrs of SC charging time. However, using evtripplanner.com I can punch in extra assumptions such as average speed, payload, HVAC usage, range buffer, etc to get a more accurate picture. By adding a 4th SC stop along the way, I can effectively cut my trip time down to 8.5hrs and save about 15 minutes of charging time. This is possible because our cars recharge much faster on a more depleted battery and slows down considerably as the battery replenishes past 40%. Generally, it doesn't seem worth my time or others waiting to charge beyond 80%.

So I set my range buffer for 10% (or 21 rated miles) and EVTP calculates the estimated time I need to charge at each SC lot make it to the next SC with ~21 miles of headroom. The other interesting assumption is vehicle speed. Many of us have noticed that the rated miles on our cluster display are rarely actualized in the real-world. According to EVTP, it's implied that the rated miles assumes an average of 58mph cruising speed; which might be arbitratary average of city/hwy speeds). Tinkering with the numbers I found the following:

An average cruising speed of 68mph would result in a 15% reduction in rated miles.
An average cruising speed of 80mph would result in a 30% reduction in rated miles.

In other words if you're showing 100 rated miles on your cluster and you're driving an average 80mph, expect to get no more than 70 miles of actual distance traveled. I'm looking forward to testing a few theories along this road trip and I'm confident that I won't unexpectedly need to slow down for Wh/mi-sake.

*I should note that charging times assume you can get the full potential charging rate without sharing a paired SC.

Great write up. You will enjoy the trip and it does wonders with increasing confidence in driving long distances.
Out here in the middle of the country we don’t have as many fast chargers so we have to be a bit studious on the planning. There is one route of about 330 miles I take quite often. The first charger is 215 miles from the house. So given I show 234 at 100% these days doesn’t leave much cushion. Onboard computer shows 5% at destination. The first time I did this I was nervous. But I have gotten quite comfortable with it now because the cars trip computer seems very accurate with dynamic adjustments during the drive. The TRIP tab under energy screen is updating every few minutes to give you arrival %. Use this tool. It is very accurate and very helpful. I simply drive fast enough to keep the number where I want it. If it starts slowly going down I knock of a few mph. And vice versa.

The point I took so long to get to was that over my long road trips in last couple years is about 65-70 mph seems to always nail the arrival % dead on. And the safety net as others have suggested is just slow down. It’s like FREE electricity! If you get in a bind and start to panic the slower you go the farther you can go. Keep in mind the hyper mile guys who set the records in these cars have gone over 600 miles on a charge by going an average of 40 mph.
And the other thing I’ve learned is if you don’t have a supercharger along the route and need to stretch a leg, it is much better to slow down and make that distance rather than stop at any level 2 charger for 30 minutes or an hour just to get 15-30 miles.
I can make up 30 miles on the car by slowing 5 mph over 200 miles easier than I can stopping to charge for an hour at slow charger. And of course 5mph over 3 hours is really only about 15 miles and 15 minutes.

The trip computer got some new algorithms recently in February and now takes much better advantage of the elevation and other factors and has gotten SO much better.

Just want to be clear. I am not advocating planning your trips around a 5% arrival state of charge. I like 10-15 much better. I only do this on that one leg until they someday add a charger in Wichita Falls to help us.
But it helps me to know it can do this and I have confidence in the system

 

[2012MS85]

I’ve always been happy with Tesla’s onboard trip planner on my 3 biggest trips with 3 different Tesli (my new plural ):

My family drove our first Tesla - 2012 S 85 - from Iowa to Bristol, TN, (near the Smokey Mountains) and back. It was about 1,800 miles over a weeklong vacation. Perfectly accurate during our August trip with lots of A/C use and a fair bit of higher speeds.

A friend and I flew to Seattle to drive home my recently purchased 2012 Sig P85 in freezing December temps. Plenty of mountain driving from the Pacific NW along I90, through Montana, on our 2,000 mile trek back to Iowa. Did I mention it was damn cold (sub-zero to a high of 40F)? This is when trip planning is most challenging, as cabin heat and 70-80mph speeds can zap HALF of your battery (EPA range). There were 22 available Supercharging stops along my route, and my pre-trip planning from Tesla’s website had me stopping at 18 of them. Reality turned out to be 20 stops due to the extreme cold. The onboard computer was pretty accurate, but my arrival State-of-Charge (SOC) would generally drop a fair bit as I drove between SCs, so I dutifully followed Tesla’s screen prompts commanding me to keep my speed below 70mph, then 65mph, etc so I’d make it to the next SC (generally with about 5% SOC, vs the 10% SOC expected arrival SOC as we left the previous SC). Never a problem; just had to be diligent and listen to your car’s orders (pretend it’s your wife, and simply obey ).

My family just finished our 3rd long trek from Iowa to Boston and back, which was about 2,400 miles in our new MR3. I did hours of pre-planning, but didn’t need to! As we left home, I gave my 3 the “Navigate to Boston” voice command and within 20-25 seconds, my exact trip route and 6 SC stops popped up on my screen. The speed and ease of the 3’s computer blows my mind

I have 100% confidence inTesla’s onboard trip planner, as it’s exceeded my expectations on all my trips, big and small.

 

[BerTX]

If I'm on a leg of a trip where I'm concerned about range, I use micro- adjustments on the cruise control setting while driving. Say I am comfortable with a 15% arrival SOC. If I'm driving and my predicted SOC drops to 14%, I'll bump the cruise setting down 1 mph. You won't even notice the change after a minute. If it drops another %, cut back another mph. Once it starts to rise, let it get back to your comfort zone and then start bumping the speed back up one mph at a time.

This prevents the "OMG I need to slow down 10 mph" on this highway where that probably isn't safe. It also keeps me aware of the SOC at all times. Kinda like a very slow video game.

 

[Mike Robinson]

The onboard computer doesn't compensate for any of those factors. While of those are indeed factors that determine range, most folks don't worry about them that much.

As you are purchasing your first EV, range anxiety is commonly a big deal. To a great degree, it severely overrated, your worry about range.

I had the 88 mile 2015 Leaf. There were indeed trips that it could make and trips that would have been tough. For many of those, there were charging options available, it just added time.

But with the 2018 Leaf at 150+ miles, it seems to be able to go forever. It becomes a car that can handle medium distance trips (100-300 mile) without much difficulty.

When you hit the 250+ miles of Teslas, it isn't much of a problem anymore. Sure, I think about it, I check it, but I don't worry about it. We recently took a trip from Atlanta to Jackson MS, to Destin FL and up to Cherokee NC, 1600 miles, and had no issues with charging. Only about half of the roads were Interstates and we spent $36 on charging.

We're at the point where we are a two EV family and have no ICE vehicles. I have no issues being able to travel just about anywhere. When I'm not on a road trip, life is so much easier. I don't have to spend time at a gas station once a week. I don't get gas spilled on me. I don't worry about oil changes, I just drive the car. When charging at home, the car has effectively unlimited distance around town, I never run out, because it always fills up overnight.

But to directly answer your question, while those items do impact the distance, speed is probably the number one killer of range. While the onboard computer doesn't really compensate for speed, it will tel you if your current consumption rate is too high to reach your next destination and will tell you to slow down. The same things should happen with any of the factors that you list, just slow down to increase/compensate for needed efficiency.

I agree, speed is a huge killer on distance, but so is large changes in elevation. When I drove from Atlanta to Nashville recently, Monteagle Mountain was a serious drain on battery!

 

[MikeBur]

Lots of great advice on here already.

Only couple of things I would add:
Rain and Wind can significantly affect fuel consumption. This should not be an issue.

For longer range journeys (be they liquid or battery-supplied, land or air) you need a level of awareness though should not cause anxiety. If you do nothing, most vehicles will tell you. As mentioned, often this approach will leave you with less alternatives than if you knew earlier.

With a Tesla it gives you many more options ahead of other cars. Listen to them and I contend you’ll have less stress. I’ve had more stress on a 300 mile trip in a gas car than I did yesterday in our 3.
eg yesterday I was on 280 mile road trip in terrible rain and I did notice the battery level was decreasing more rapidly then expected; I checked on the trip planner graph and was 14% off expected, even with the rain I didn’t expect that much. I used the website teslawaze (on car screen) and overlaid weather map; in addition to the rain, I was driving into a 20mph headwind and hadn’t noticed (autopilot). I decided to reroute and chose a freeway where the wind was predominantly perpendicular to the car and passed the area of issue. I think this is amazing to have these options in real-time
Btw I have purposely ran my S do to 0% when I arrived home. I can tell you if you do nothing, the car will get more aggressive about ensuring you make it to where you’re going, from simple info available, to warnings, and yes eventually to power-availability reductions. Road warriors such as the above know better than to react, rather adapt and overcome