Range with 1 person vs 3 persons (Roadtrip)

[artnalex]

I am about to go on my first roadtrip!

I am traveling from La Verne, CA to Scottsdale, AZ. There will be 3 of us. Does the Model Y take into account added weight when calculating its battery range? (I assume additional weight negatively affects the cars ability to achieve its maximum driving range.)

I ask because I did a routeplanner that instructs me to drive 210 miles before arriving at my first Supercharging station on Blythe, AZ. . I am sure I can drive 210 miles with only me, BUT...I will have my son and wife as well. That’s an additional 370-lbs in the car (my son is a big boy).

I know I can always stop at a closer Supercharging location, but I wonder if my car’s navigation/brain/battery take into account the added weight-load when estimating battery range.

Any personal experience and guidance is appreciated.

 

[jmaddr]

It won’t affect too too much, but to be on the conservative side, use ABRP and increase your reference kwhr/mi by 20-30% (which is likely too much all things considered) and then monitor as you drive and compare the output. Every situation is different.

 

[KerryOH]

See ABRP app settings

 

[Zoomit]

The question of passenger or cargo weight impact on range comes up in different forms fairly frequently. It’s a reasonable question if you’re not familiar with the physics. Let’s consider the question of how much headwind might be equivalent to an additional 370 lb of cargo. Is it 5 mph or maybe 10 mph? If you don’t know or if these numbers sound reasonable stand by for a surprise.

First some reasonable, simplifying assumptions: 1) the trip starts and ends at the same elevation and 2) the trip is at constant highway speeds.

Rolling resistance increase
Let’s say the 370 lbs is added to a 4600 lb Model Y including the driver. That’s an 8% increase. So the rolling resistance increases by 8%.

Total consumption increase
At highway speeds, the energy needed to overcome rolling resistance is about 1/6 (17%) of the total energy needed to keep the vehicle going at a steady speed. So the total increase in consumption with the extra weight is 17% x 8% or 1.4%.

Equivalent headwind
Before the final calculation, recognize that if you were outside in a 5 mph wind you’d be hard-pressed to notice it. You’d likely say the wind was “calm”. Based on calculations I did for another thread, a 2 mph headwind increases energy consumption by 4% at 75 mph. For this scenario, the math is 1.4% / 4% x 2 mph = 0.7 mph.

So adding 370 lbs is equal to a headwind of 0.7 mph. This is an order of magnitude lower than “light winds”, which you’d most likely not even consider when trip planning. If there was a prediction for a 7 mph headwind for the whole trip, you might not even be concerned before starting out, yet that headwind would have more than ten times the effect on range than adding the 370 lb.

The moral of the story is don’t worry about weight on long-distance trips, worry about the winds.

 

[Electric > Gas]

The question of passenger or cargo weight impact on range comes up in different forms fairly frequently. It’s a reasonable question if you’re not familiar with the physics. Let’s consider the question of how much headwind might be equivalent to an additional 370 lb of cargo. Is it 5 mph or maybe 10 mph? If you don’t know or if these numbers sound reasonable stand by for a surprise.

First some reasonable, simplifying assumptions: 1) the trip starts and ends at the same elevation and 2) the trip is at constant highway speeds.

Rolling resistance increase
Let’s say the 370 lbs is added to a 4600 lb Model Y including the driver. That’s an 8% increase. So the rolling resistance increases by 8%.

Total consumption increase
At highway speeds, the energy needed to overcome rolling resistance is about 1/6 (17%) of the total energy needed to keep the vehicle going at a steady speed. So the total increase in consumption with the extra weight is 17% x 8% or 1.4%.

Equivalent headwind
Before the final calculation, recognize that if you were outside in a 5 mph wind you’d be hard-pressed to notice it. You’d likely say the wind was “calm”. Based on calculations I did for another thread, a 2 mph headwind increases energy consumption by 4% at 75 mph. For this scenario, the math is 1.4% / 4% x 2 mph = 0.7 mph.

So adding 370 lbs is equal to a headwind of 0.7 mph. This is an order of magnitude lower than “light winds”, which you’d most likely not even consider when trip planning. If there was a prediction for a 7 mph headwind for the whole trip, you might not even be concerned before starting out, yet that headwind would have more than ten times the effect on range than adding the 370 lb.

The moral of the story is don’t worry about weight on long-distance trips, worry about the winds.

This might be the best response I've ever seen.

 

[qdeathstar]

What if the one person weighs as much as three people? Asking for a f... I mean.... nvm

 

[JimBob 909]

Our first road trip was West Covina to Sedona. One thing you can do is before Indio, look at your estimated remaining range and estimated SOC upon arrival at Blythe (Ehrnberg,AZ) and stop for a few minutes in Indio if you want a cushion. We did on the way to Sedona, but went from Buckeye to Indio without stopping on the return trip.

Stopping at Buckeye then would get you to Scottsdale with range to spare.

have a safe journey and enjoy your road trip and the car.

 

[cstork]

The question of passenger or cargo weight impact on range comes up in different forms fairly frequently. It’s a reasonable question if you’re not familiar with the physics. Let’s consider the question of how much headwind might be equivalent to an additional 370 lb of cargo. Is it 5 mph or maybe 10 mph? If you don’t know or if these numbers sound reasonable stand by for a surprise.

First some reasonable, simplifying assumptions: 1) the trip starts and ends at the same elevation and 2) the trip is at constant highway speeds.

Rolling resistance increase
Let’s say the 370 lbs is added to a 4600 lb Model Y including the driver. That’s an 8% increase. So the rolling resistance increases by 8%.

Total consumption increase
At highway speeds, the energy needed to overcome rolling resistance is about 1/6 (17%) of the total energy needed to keep the vehicle going at a steady speed. So the total increase in consumption with the extra weight is 17% x 8% or 1.4%.

Equivalent headwind
Before the final calculation, recognize that if you were outside in a 5 mph wind you’d be hard-pressed to notice it. You’d likely say the wind was “calm”. Based on calculations I did for another thread, a 2 mph headwind increases energy consumption by 4% at 75 mph. For this scenario, the math is 1.4% / 4% x 2 mph = 0.7 mph.

So adding 370 lbs is equal to a headwind of 0.7 mph. This is an order of magnitude lower than “light winds”, which you’d most likely not even consider when trip planning. If there was a prediction for a 7 mph headwind for the whole trip, you might not even be concerned before starting out, yet that headwind would have more than ten times the effect on range than adding the 370 lb.

The moral of the story is don’t worry about weight on long-distance trips, worry about the winds.

Actually, I think 8% additional weight will increase rolling resistance by less than 8%. Much of the rolling resistance is in the motors & gears, not the weight bearing wheels. This supports your contention that reduced range from additional weight is negligible.

 

[alcfeoh]

@Zoomit I definitely agree with the wind playing a huge part. On a big road trip recently, we had headwinds and my range kept dropping no matter how I drove. It was a bit scary as the Tesla route planner seemed to be way off no matter what. It's definitely something Tesla should take into account in the future. They do a great job taking elevation and speed into account, winds would make it all nearly perfect.

 

[maximizese]

Yes the winds (strong headwind or tailwind) can play a significant difference in range with an electric vehicle, and energy increase/decrease in any vehicle. A few years ago I was driving our S85 eastward into a strong headwind...25mph sustained winds and 50 gusts through the high desert into Moreno Valley. I barely made it from Quartzsite to Indio. Surprising my range took a huge hit from Indio to Cabazon, so I made an unscheduled stop to charge there since I already burned 80 range miles to go 37 real miles.

Speed and wind resistance (air displacement) plays a much bigger role in energy consumption/ range than a couple hundred lbs of payload. Remember that energy equals 1/2 Mass times Velocity squared.

Generally I’ll give myself a 10% reserve on the battery when I arrive at a SuC and I’ll recalculate the onboard navigation to see if I can stretch it to a SuC site that’s further out, but I find myself checking the Energy window with the trip view to make sure I’m on pace with my projected energy consumption. I’ve had to decrease speed in high winds a few times to make sure I got to the next leg, but then of course everyone should decrease speed in high winds for safety reasons.

 

[Bad Dolphin]

Can’t speak to quantitative wind effects on our Model 3 because our trips here in Maui are so short, but can certainly attest to wind and our Sprinter one-ton towing an Airstream from SoCal to Texas and from SoCal to Washington state.

Tailwinds would make huge differences, as you’re effectively driving in air moving with you, so air resistance from the front is proportionally reduced. Headwinds are obvious—driving 60 with a 15 mph headwind means the rig is feeling the same as going 75 in still air—huge difference.

The interesting part is the effect of crosswinds on efficiency—no matter the direction, this also reduced efficiency tremendously. My theory was that Mercedes’ excellent anti-rollover system that lightly braked alternative wheels of course would decrease efficiency.

Has anyone experienced the same with crosswinds in the Model 3? Here in Maui, we tend to have strong winds (one of the many reasons that, as windsurfers, we moved here.) Whether going up or down the hill (we live at 2000 ft up the 10,000 ft mount), I have noticed (in range changes) but not yet quantified a big difference when the wind (crosswind) is strong.

Anybody?

 

[animorph]

The car considers the last 30 miles or so you've driven when calculating the charge remaining at destination. It updates that estimate as you drive. So yes, wind and weight are included in that particular number, though it is of course still an estimate. You may encounter a wind or weather change along the way, or decide to drive 100 MPH for a while, things the car won't know until they happen. Keep an eye on the charge remaining at destination. If it gets too low for you, slow down or plan to charge earlier.

Weight is not a big factor. You can try the route in ABRP with different weights and see for yourself. I've driven our X from Scottsdale to Palo Alto, CA many times, empty and with a full load. I've always stopped at the same chargers that we like to use. We may well have stopped a little longer at each one when fully loaded, but I never noticed a difference. We just leave when the nav says we have our 15% charge remaining at destination. And a little more if conditions look variable and unfavorable for efficiency.

 

[enmore20201]

What if the one person weighs as much as three people? Asking for a f... I mean.... nvm

Then make sure you take only one of them????

 

[artnalex]

Thanks everyone. I appreciate the feedback thus far, and look forward to any additional comments.

So far, I think I will just recharge in Indio, CA (107 miles away from starting point) and then again in Quartzite,AZ (120 miles past Indio, CA) before arriving to Scottsdale, AZ.

 

[Klagio]

Yes the winds (strong headwind or tailwind) can play a significant difference in range with an electric vehicle, and energy increase/decrease in any vehicle. A few years ago I was driving our S85 eastward into a strong headwind...25mph sustained winds and 50 gusts through the high desert into Moreno Valley. I barely made it from Quartzsite to Indio. Surprising my range took a huge hit from Indio to Cabazon, so I made an unscheduled stop to charge there since I already burned 80 range miles to go 37 real miles.

Speed and wind resistance (air displacement) plays a much bigger role in energy consumption/ range than a couple hundred lbs of payload. Remember that energy equals 1/2 Mass times Velocity squared.

Generally I’ll give myself a 10% reserve on the battery when I arrive at a SuC and I’ll recalculate the onboard navigation to see if I can stretch it to a SuC site that’s further out, but I find myself checking the Energy window with the trip view to make sure I’m on pace with my projected energy consumption. I’ve had to decrease speed in high winds a few times to make sure I got to the next leg, but then of course everyone should decrease speed in high winds for safety reasons.

Well sometimes wind is from the back, so that helps .. can't be unlucky all the time. If I am not mistaken the majority of time thw wind is from west to east (rotation of the earth)

 

[Klagio]

Thanks everyone. I appreciate the feedback thus far, and look forward to any additional comments.

So far, I think I will just recharge in Indio, CA (107 miles away from starting point) and then again in Quartzite,AZ (120 miles past Indio, CA) before arriving to Scottsdale, AZ.

Yeah so basically get yourself an anemometer instead of a weight scale LOL

 

[Klagio]

The car considers the last 30 miles or so you've driven when calculating the charge remaining at destination. It updates that estimate as you drive. So yes, wind and weight are included in that particular number, though it is of course still an estimate. You may encounter a wind or weather change along the way, or decide to drive 100 MPH for a while, things the car won't know until they happen. Keep an eye on the charge remaining at destination. If it gets too low for you, slow down or plan to charge earlier.

Weight is not a big factor. You can try the route in ABRP with different weights and see for yourself. I've driven our X from Scottsdale to Palo Alto, CA many times, empty and with a full load. I've always stopped at the same chargers that we like to use. We may well have stopped a little longer at each one when fully loaded, but I never noticed a difference. We just leave when the nav says we have our 15% charge remaining at destination. And a little more if conditions look variable and unfavorable for efficiency.

ehehh, so next time I will organize my trip, I will do like with my boat: zig-zag if headwind, staright if tailwind

 

[STBR0510]

Don't panic and carry a towel.

Just got my Model Y last week and I'm taking my 1st road trip as well. VA to MN.

 

[qdeathstar]

Sounds like a nice drive....

 

[X-pilot]

Well sometimes wind is from the back, so that helps .. can't be unlucky all the time. If I am not mistaken the majority of time thw wind is from west to east (rotation of the earth)

Would driving in reverse change a head wind into a tail wind is the question?

Just kidding, of course.