Real World Hwy efficiency numbers

[borski]

This has nothing to do with highway efficiency, but "Notch EV" recently posted a video in which he spent the night sleeping in his Gravity to check out its viability for camping.

With the cabin temperature set to maintain 73º and an outside low of 44º, the car used .78% of battery capacity per hour. That strikes me as pretty good.

That’s amazing. It speaks to the insulation more than how efficient the heat pump is or anything, I’d guess.

 

[hmp10]

That’s amazing. It speaks to the insulation more than how efficient the heat pump is or anything, I’d guess.

I'm actually finding this more a hindrance than a boon right now.

Our Gravity has been sitting for several days now at a charge level well above the 80% limit I set and asked the Service Center to maintain. They said they would drain the battery down (presumably using V2V charging?), but so far they haven't. And right now it's looking as if they can't find a transport to bring the car back to us.

So I've been using the climate control system via the mobile app to run the temperature alternately up and back down in the cabin in an attempt to drain the battery myself for the past two days. I still haven't been able to get it back down to 80%.

 

[borski]

I'm actually finding this more a hindrance than a boon right now.

Our Gravity has been sitting for several days now at a charge level well above the 80% limit I set and asked the Service Center to maintain. They said they would drain the battery down (presumably using V2V charging?), but so far they haven't. And right now it's looking as if they can't find a transport to bring the car back to us.

So I've been using the climate control system via the mobile app to run the temperature alternately up and back down in the cabin in an attempt to drain the battery myself for the past two days. I still haven't been able to get it back down to 80%.

Which still points to how impressive the insulation is, haha. There is rarely ever a time when someone *wants* leakage, but you seem to have found it!

 

[hmp10]

Which still points to how impressive the insulation is, haha.

Yes, it does. Since so much of the cabin is glass, I'm thinking it's the effectiveness of the IR reflectivity at play in keeping external heat out and internal heat in?

 

[Quimby]

We have the 2023 pure AWD. Last year we showed 316miles range @ 80% charge. Today it is 300 miles @ 80%. It has 26,000 miles showing.

 

[TahoeMichael]

This has nothing to do with highway efficiency, but "Notch EV" recently posted a video in which he spent the night sleeping in his Gravity to check out its viability for camping.

With the cabin temperature set to maintain 73º and an outside low of 44º, the car used .78% of battery capacity per hour. That strikes me as pretty good.

I'd consider it just acceptable. On the one hand, 10 hours of temperature maintenance for 7.8% of charge will work fine for most scenarios. On the other hand, that seems to be ~860 watts being drawn continuously by the heat pump to maintain temperature. It's hard to improve efficiency when it comes to thermodynamics, but that strikes me as a bit high. My guess is that it's a product of a glass roof decreasing overall cabin insulation.

 

[borski]

I'd consider it just acceptable. On the one hand, 10 hours of temperature maintenance for 7.8% of charge will work fine for most scenarios. On the other hand, that seems to be ~860 watts being drawn continuously by the heat pump to maintain temperature. It's hard to improve efficiency when it comes to thermodynamics, but that strikes me as a bit high. My guess is that it's a product of a glass roof decreasing overall cabin insulation.

… with a nearly 30 degree differential.

 

[Elfin]

I'd consider it just acceptable. On the one hand, 10 hours of temperature maintenance for 7.8% of charge will work fine for most scenarios. On the other hand, that seems to be ~860 watts being drawn continuously by the heat pump to maintain temperature. It's hard to improve efficiency when it comes to thermodynamics, but that strikes me as a bit high. My guess is that it's a product of a glass roof decreasing overall cabin insulation.

Cars are just horribly insulated. The AC on a large car is 20,000 BTU, enough for a small apartment.

 

[MACOSTEON]

So, for those lucky enough to already have a Gravity. If you have done any long-distance driving, would you mind posting efficiency maybe with tire size, speed, and weather if meaningful. I'm most interested in 80 mph in cold weather but being the middle of summer what can you do.

 

[MACOSTEON]

I have about 1090 miles. I have a 7 seater Gravity GT. I put numbers in Chat GPT 5 to generate mt data.

My home charing data to 100% listed
At 75 mph: 2.81 efficiency

Cost analysis for home chargers/ 250 Kwatt/ 350 Kwatt data.

 

[MACOSTEON]

So far my GDE gets 2.74 miles/kwh over 600 miles. In hot sun in south Florida about 95 degrees when driving. I have 22/23 wheels. Most of these miles were on the highway at 75-80mph. Not that impressive so far. They do say in the owners manual that it is not as efficient in the first 2000 miles. The GDE with these wheels is only anticipated to get 370 miles on a charge. I believe that a range of 370 for the GDE with the large wheels is a best case scenario driving like your grandmother. I am getting closer to 335 miles

And for fun I put the AI version of what I wrote: So far, my GDE has achieved an impressive 2.74 miles per kilowatt-hour (kWh) over a distance of 600 miles. During this journey, I drove in the scorching sun of south Florida, where the temperature reached a sweltering 95 degrees Fahrenheit. I’m equipped with 22/23 wheels, and most of these miles were covered on the highway at speeds ranging from 75 to 80 miles per hour. While this may not seem particularly impressive at first glance, it’s worth noting that the owner’s manual does mention that the GDE’s efficiency decreases in the initial 2000 miles. Considering these factors, the GDE with these wheels is only expected to provide a range of 370 miles on a single charge. In my opinion, this is a best-case scenario, assuming I drive in a leisurely manner similar to my grandmother. I’m currently getting closer to reaching a range of 335 miles.

 

[Ron_Burgundy]

I have about 1090 miles. I have a 7 seater Gravity GT. I put numbers in Chat GPT 5 to generate mt data.

My home charing data to 100% listed
At 75 mph: 2.81 efficiency

Cost analysis for home chargers/ 250 Kwatt/ 350 Kwatt data.

These are similar to my back of the envelope costs. DC charging costs are more in line with gas, but since I don’t do it often, my blended cost per mile is much lower than gas. Plus, it’s an f’in’ rocket ship.

 

[TahoeMichael]

Cars are just horribly insulated. The AC on a large car is 20,000 BTU, enough for a small apartment.

It's true, but that's also because people want the blast of shockingly cold air when they're feeling hot and sweaty. That many BTUs aren't necessary to hold a given temperature once it's reached.

 

[niceInBoston]

I have about 1090 miles. I have a 7 seater Gravity GT. I put numbers in Chat GPT 5 to generate mt data.

My home charing data to 100% listed
At 75 mph: 2.81 efficiency

Cost analysis for home chargers/ 250 Kwatt/ 350 Kwatt data.

If you don’t mind me asking, what is your wheel size, and what mode do you tend to drive in (sprint, smooth, etc)?

 

[Ron_Burgundy]

If you don’t mind me asking, what is your wheel size, and what mode do you tend to drive in (sprint, smooth, etc)?

They’ll likely mind you asking. I mean, that’s an incredibly personal question…

 

[gmoney]

So far my GDE gets 2.74 miles/kwh over 600 miles. In hot sun in south Florida about 95 degrees when driving. I have 22/23 wheels. Most of these miles were on the highway at 75-80mph. Not that impressive so far. They do say in the owners manual that it is not as efficient in the first 2000 miles. The GDE with these wheels is only anticipated to get 370 miles on a charge. I believe that a range of 370 for the GDE with the large wheels is a best case scenario driving like your grandmother. I am getting closer to 335 miles

And for fun I put the AI version of what I wrote: So far, my GDE has achieved an impressive 2.74 miles per kilowatt-hour (kWh) over a distance of 600 miles. During this journey, I drove in the scorching sun of south Florida, where the temperature reached a sweltering 95 degrees Fahrenheit. I’m equipped with 22/23 wheels, and most of these miles were covered on the highway at speeds ranging from 75 to 80 miles per hour. While this may not seem particularly impressive at first glance, it’s worth noting that the owner’s manual does mention that the GDE’s efficiency decreases in the initial 2000 miles. Considering these factors, the GDE with these wheels is only expected to provide a range of 370 miles on a single charge. In my opinion, this is a best-case scenario, assuming I drive in a leisurely manner similar to my grandmother. I’m currently getting closer to reaching a range of 335 miles.

Afternoon All,

I just completed at 400 mile highway driving between 65-85 miles an hour on my Gravity with mid sized tires at 70 degree cloudy weather. The range we got put 2.65 miles per kilowatt. Keep in mind that most of the driving was 80 miles per hour.

We also stopped at a 180 charger stop and it stayed around 180 the whole time from 15-65%

 

[Ron_Burgundy]

Afternoon All,

I just completed at 400 mile highway driving between 65-85 miles an hour on my Gravity with mid sized tires at 70 degree cloudy weather. The range we got put 2.65 miles per kilowatt. Keep in mind that most of the driving was 80 miles per hour.

We also stopped at a 180 charger stop and it stayed around 180 the whole time from 15-65%

This is with a 7 seater, right? Thanks for the data!

70+ MPH really does crush efficiency - especially when combined with less regen in highway driving. But that’s true for all EVs I’ve owned.

 

[TahoeMichael]

Afternoon All,

I just completed at 400 mile highway driving between 65-85 miles an hour on my Gravity with mid sized tires at 70 degree cloudy weather. The range we got put 2.65 miles per kilowatt. Keep in mind that most of the driving was 80 miles per hour.

We also stopped at a 180 charger stop and it stayed around 180 the whole time from 15-65%

For 118 kWh usable battery, that's 312 miles of range at 80 mph. Very satisfactory from my perspective. And if a 15% -> 65% charge is 59 kWh, with 95% charging efficiency, then I speculate you charged for about 20 minutes to get 156 miles of range. Not bad at all, but of course a higher powered charger would be the best experience.

 

[hmp10]

For 118 kWh usable battery, that's 312 miles of range at 80 mph. Very satisfactory from my perspective. And if a 15% -> 65% charge is 59 kWh, with 95% charging efficiency, then I speculate you charged for about 20 minutes to get 156 miles of range. Not bad at all, but of course a higher powered charger would be the best experience.

Kyle Conner says the Gravity has 123 kWh usable, with about 126 kWh total.

Either way, I agree the Gravity range is satisfactory. For me, the access to Superchargers and the charging speed actually moots any concern about range and efficiency. Our Air mostly succeeded in giving what I most want in an EV: a high-performance car that will get me from one bathroom break to another driving the way I please. The only limitation the Air left us with was the mostly crappy CCS charging infrastructure in the southeast. The addition of Supercharger access with the Gravity overcame even that limitation.

Remember that three hours of driving at 80mph means 240 miles. Very few people can or care to drive more than three hours without a break, and the Gravity can do that with a yawn under almost any conditions and with margin to spare.

 

[illopp00]

Yes, it does. Since so much of the cabin is glass, I'm thinking it's the effectiveness of the IR reflectivity at play in keeping external heat out and internal heat in?

Get them to plug in a space heater to one of the outlets?