Notch EV's full battery to zero range tests

[dbsb3233]

Was he using regen? My Air gets better mileage without regen.

I've seen some say that but it doesn't make sense to me. If the highway is mostly flat, cruising at 70 MPH isn't gonna use regen anyway because you're not slowing down. If it's got a lot of up and down, yeah, you'll use some regen on the downs if it's steep enough, but the alternative is to either let the car run up to 80+ on the downhills, or use friction brakes which is highly inefficient (because as I understand it, the Gravity brake pedal doesn't apply any regen at all).

The only scenario I see maybe a slight loss is if there's lots of short rolling hills, where you're better letting the car just speed up 2-3 MPH on the down dips rather than have regen slow you on those. But if it's anything longer than a short dip, then the car is gaining too much speed not to slow it down.

The brake pedal not using regen makes it especially costly not to have regen on, if you need to hit the brake pedal much at all. Or at least that's what seems logical to me. Am I missing something?

 

[hmp10]

450 to 358 is a loss of 92 miles of range. That's a 20% loss of range, which I find devastating.
My Tesla Model X's have gotten real world ranges better than 90% of rated range consistently. So with a Tesla rated at 352 miles, I suspect in the real world the 5-seater Gravity and small wheels isn't that much better, and with both vehicles at 3-rows, I wonder just how small that difference will be (Model X range doesn't change on 3rd row, hmm).

Fast charging is only somewhat helpful, and does not replace actual range. It's not the stopping, it's the finding chargers when and where you want to stop. Already, I see Tesla has reserved 3 of the chargers we've used the most for Tesla vehicles only, so that sucks, too.

EPA range is basically a farce in terms of assessing an EV's road-tripping chops. To me, only three things matter:

- actual range for the way you drive
- availability of chargers
- charging speed

The Gravity is the current world-beater on all three scores.

Our Lucid Air and our Tesla Model S saw similar declines from rated ranges in repeated and pretty well-controlled 80-mph range tests across Alligator Alley (around 78% of rated range in the Air and around 72-74% in the Model S). However, the Air had so much more rated range than the Model S that the real-world difference in their actual ranges was about 100 miles.

I think the numbers will play out similarly with the Gravity. And the fact that the Gravity charges faster than any Tesla and has access to CCS chargers as well as Superchargers makes it no contest on road tripping, at least as far as I'm concerned.

I still have concerns about putting our Gravity on the road, but real-world highway range is not one of them.

 

[Bdr100]

You understand the difference between efficiency and range, right? Anyone can make an EV with 700 miles of range by putting lots and lots of batteries in it. Gravity is more efficient than Escalade IQ with less battery, and weighs several thousand pounds less. I fail to see a problem.

Yes, I understand the difference between range and efficiency. The post mentioned “Range”, so I was citing the best Range in class. Best efficiency might be the Model Y which is very efficient but not near the range. The Gravity falls in that happy in between, longer range that Model Y and better efficiency than Escalade IQ.

 

[borski]

The Gravity -- with its NACS plug and charging speed -- is the first EV we've owned that puts highway range concerns completely to bed for us. We drive it as we like on a road trip -- 80-85 mph with occasional bursts to break out of traffic clumps -- and we can always find a charger (preferably a Supercharger because of their greater reliability) by the time our bladders start insisting on a stop. And we almost always finish the charging before we're wrapped up using the bathroom, picking out snacks, and downing them.

This is doing it right.

 

[borski]

EPA range is basically a farce in terms of assessing an EV's road-tripping chops. To me, only three things matter:

- actual range for the way you drive
- availability of chargers
- charging speed

The Gravity is the current world-beater on all three scores.

Our Lucid Air and our Tesla Model S saw similar declines from rated ranges in repeated and pretty well-controlled 80-mph range tests across Alligator Alley (around 78% of rated range in the Air and around 72-74% in the Model S). However, the Air had so much more rated range than the Model S that the real-world difference in their actual ranges was about 100 miles.

I think the numbers will play out similarly with the Gravity. And the fact that the Gravity charges faster than any Tesla and has access to CCS chargers as well as Superchargers makes it no contest on road tripping, at least as far as I'm concerned.

I still have concerns about putting our Gravity on the road, but real-world highway range is not one of them.

I couldn’t agree with all of this more.

I stopped buying computers because their CPU went up by 400MHz a long time ago.

I care much more about how the thing solves my problems and fits into my life now than I do about chasing a number for bragging rights.

I know it matters a lot more to some people, and that’s fine. But I’ve never hit my efficiency numbers because I don’t like driving that way, heh.

 

[TahoeMichael]

Not even close to class leading EV range. Cadillac Escalade IQ has 460 miles EPA and 482 miles per State of Charge test.

Spot on. I was really trying to say efficiency. I've never considered the caddy as an alternative because of the time required to recharge its giant battery.

 

[TahoeMichael]

Not even close to class leading EV range. Cadillac Escalade IQ has 460 miles EPA and 482 miles per State of Charge test.

Hmm, I was curious to see what Car & Driver managed, and I see that they managed 380 miles on their 75 mph test. Still better than what NotchEV reports, but much much less than 482. Now I guess curiosity will make me go see what State of Charge did different.

 

[hmp10]

Yes, I understand the difference between range and efficiency. The post mentioned “Range”, so I was citing the best Range in class. Best efficiency might be the Model Y which is very efficient but not near the range. The Gravity falls in that happy in between, longer range that Model Y and better efficiency than Escalade IQ.

I said "actual range for the way you drive". And, as I've said, the way I drive on road trips is in the mid-80's.

Aerodynamic drag and its exponential relationship to speed is the biggest single factor in range when considering the difference between an Escalade at 70 mph and a Gravity at 85 mph. Given the Escalade's slightly higher Cd and considerably greater frontal area (not to mention its extra 3,000 pounds of weight), the comparative range numbers will shift dramatically toward the Gravity as speeds increase.

 

[TahoeMichael]

I said "actual range for the way you drive". And, as I've said, the way I drive on road trips is in the mid-80's.

Aerodynamic drag and its exponential relationship to speed is the biggest single factor in range when considering the difference between an Escalade at 70 mph and a Gravity at 85 mph. Given the Escalade's slightly higher Cd and considerably greater frontal area (not to mention its extra 3,000 pounds of weight), the comparative range numbers will shift dramatically toward the Gravity as speeds increase.

I just went and looked at the State of Charge results for the Escalade. They saw a 22% decrease in m/kWh when they increased speed from 60 to 70 mph (2.7 m/kWh went down to 2.1 m/kWh). I imagine that going to 80 mph would see just as big an efficiency decrease (quite possibly bigger).

 

[9point81]

I couldn’t agree with all of this more.

I stopped buying computers because their CPU went up by 400MHz a long time ago.

I care much more about how the thing solves my problems and fits into my life now than I do about chasing a number for bragging rights.

I know it matters a lot more to some people, and that’s fine. But I’ve never hit my efficiency numbers because I don’t like driving that way, heh.

Boom! Yeah, I know this car gets enough range and charging availability/speed to where I don't really care how I drive anymore with regards to speed and efficiency/range. In our EV9 on road trips, I was very careful as generally at best it did about 240-250 miles if I drive at my normal highway blasting along speeds. In winter it's just about less than 200 miles and at 80% charge, less than that. The Gravity so far has blown away the range on the EV9 and given me enough comfort to not care about it anymore and just drive. Like I always wanted to be able to do in EVs. We are finally at that point where it's just flat easy to road trip with no range or charging anxiety in Gravity.

 

[9point81]

Was he using regen? My Air gets better mileage without regen.

He was using Dream Drive, so it doesn't matter for the most part if regen is on or not.

 

[bicycleguy]

I've seen some say that but it doesn't make sense to me. If the highway is mostly flat, cruising at 70 MPH isn't gonna use regen anyway because you're not slowing down. ...

Remember, cruise control (or just driving yourself) is an error amplifier, constantly looking for small changes from the desired speed and the current speed and then applying power or lack of power to make the error zero. Having high regen on is kind of like turning up the gain of the error detection, except only on the high side of the speed error. Instead of just letting off the gas, the system tries to charge the battery. It will inevitably slow the car down more than it should because by the time it notices the error has changed, it (the error) is more than with regen off because the car is slowing down quicker. The system then has to apply more throttle to get the vehicle back up to speed. This up and down nature is indicative of a control system. Over and undershoots add additional currents in the wires and motors and cause more resistive heat losses. Note that in DD or whatever these on and offs may be faster than you can detect. Presumably, the software has been tuned to eliminate any additional regen error. I almost laughed writing that given all the software problems, but I think the drive software team is different.

Since I'm only 7 months waiting for my Gravity, I can't tell you for sure what the Gravity does.

 

[Xminus6]

I think the outcome isn't shocking. Car & Driver seems to be rating the Air at about 80% of EPA range on their 75 mph highway test. 80% of the Gravity's 450 EPA range is 360. In the NotchEV video, he's going 71, not 75. But it was on the colder side, and the m/kWh declined as the night wore on and temperature fell yet farther.

Perhaps more puzzling is the 115.4 kWh consumed, versus the 118 that this forum seems to have assumed is the usable capacity of the 123 kWh pack. If NotchEV's peak m/kWh was maintained across 118 kWh, that'd be 373 miles of range.

Regardless, 359 miles of range seems to be class leading for an EV SUV. I do want to see a 75 mph range test, and am looking forward to other tests being done. I've felt all along that 350 miles of range would be plenty to satisfy me, and I've never expected to get close to 450 miles at highway speeds.

I was talking to some friends today who were checking out my Gravity. If the EV9 had a real-world range in the mid 300s I would probably have been driving one for a while now. I like most everything about the car but the range. Obviously it’s not going to be as nice as a Gravity but a two-third of the cost it shouldn’t compete at every level.

 

[dbsb3233]

Remember, cruise control (or just driving yourself) is an error amplifier, constantly looking for small changes from the desired speed and the current speed and then applying power or lack of power to make the error zero. Having high regen on is kind of like turning up the gain of the error detection, except only on the high side of the speed error. Instead of just letting off the gas, the system tries to charge the battery. It will inevitably slow the car down more than it should because by the time it notices the error has changed, it (the error) is more than with regen off because the car is slowing down quicker. The system then has to apply more throttle to get the vehicle back up to speed. This up and down nature is indicative of a control system. Over and undershoots add additional currents in the wires and motors and cause more resistive heat losses. Note that in DD or whatever these on and offs may be faster than you can detect. Presumably, the software has been tuned to eliminate any additional regen error. I almost laughed writing that given all the software problems, but I think the drive software team is different.

Since I'm only 7 months waiting for my Gravity, I can't tell you for sure what the Gravity does.

I get all that, and I can see it for the case of frequent short rolling hills. Frequent short bursts of regen slowing over many little dips (vs just letting the car gain speed) could perhaps add up to something significant vs just letting the car coast. But I don't really see it for flatter roads (where the car almost never dips into the negative because it's still having to apply positive power to keep moving 70+). And I really don't see it on long mountain descents where you have no choice but to slow the car down because you aren't just gonna let it run unchecked up to 80, 85, 90+. And in that case you WANT regen because the alternative is friction brakes that recapture nothing at all (the least efficient). So unless the terrain is frequent small undulating dips, I just don't see it being significant. I could be wrong, but that's the only scenario that seems to make sense to me for regen actually being a negative.

And of course all this applies by simply having any kind of cruise control on too, which most everyone uses on road trips. Which kinda makes the regen setting moot for this context.

 

[illopp00]

It did only pull 115Kwhr from the pack which is likely not near 100%, OoS just drove a Sapphire 20 extra miles below 0%. Depends on the test procedure, I kind of agree it should be foot to the floor and can't maintain 70mph. Would have been nice to see the energy breakdown UI as well. Otherwise, either C&D or Edmunds stop the test at a more realistic or practical level of 10 miles remaining based on the car so that they can guarantee they can make it somewhere without being dead. EPA drives until dead/no power.

 

[Adnillien]

It did only pull 115Kwhr from the pack which is likely not near 100%, OoS just drove a Sapphire 20 extra miles below 0%. Depends on the test procedure, I kind of agree it should be foot to the floor and can't maintain 70mph. Would have been nice to see the energy breakdown UI as well. Otherwise, either C&D or Edmunds stop the test at a more realistic or practical level of 10 miles remaining based on the car so that they can guarantee they can make it somewhere without being dead. EPA drives until dead/no power.

In the Air, Lucid keeps about 4kWhr below zero miles, they likely do the same with Gravity. In order to get the full range you would have to drive it until the car stops. In reality, most of us will not even drive to zero, so using the zero miles remaining from the car is not a bad method.

 

[Elfin]

Lucid Air goes ~500mi at 70mph.
Gravity has 20% higher drag coefficient and 20% more frontal area.
500 * 1/1.2 * 1/1.2 = 347mi. Physics remains undefeated.

Was he using regen? My Air gets better mileage without regen.

No, he's on a flat road with cruise control on.

My Tesla Model X's have gotten real world ranges better than 90% of rated range consistently. So with a Tesla rated at 352 miles, I suspect in the real world the 5-seater Gravity and small wheels isn't that much better, and with both vehicles at 3-rows, I wonder just how small that difference will be (Model X range doesn't change on 3rd row, hmm).

A Model X does not achieve its EPA range at 70mph in the tests I see. It does look like it's a little bit more efficient though despite having the same aerodynamic drag. It is a little lighter.

 

[dbsb3233]

In the Air, Lucid keeps about 4kWhr below zero miles, they likely do the same with Gravity. In order to get the full range you would have to drive it until the car stops. In reality, most of us will not even drive to zero, so using the zero miles remaining from the car is not a bad method.

Yes, 100%-0% is the logical range measure, even though the car probably holds a modest reserve. And even though it would be dumb to try and drive it all the way down to 0% on a normal drive (rather than an intentional range test).

We know to translate 100%-0% into practical drive range of 100%-10% (or 80%-10% if it's a midday DCFC).