My "controlled" experiment

[Adnillien]

Sure. I did a very simple calc based on my total estimate of range as follows.
On the way there, I calculated that the actual mileage I got in the car was 71% of the stated EPA range. More specifically, I left the house with 100% battery or 425 miles on the car’s estimated range. When I stopped to charge (since my wife wanted to stop) we were at 31% Soc or 131 estimated range left in the car. The difference between 425 and 131 was 294 miles of estimated range used while we actually had driven 209 miles. When you divide 209/294 you get 71%. So assuming I get 71% of the left over range on the car, the car’s total range would be 425*.71=302 miles. So a simple 302 miles / the battery capacity of 92 kw= 3.28 or 3.3 miles per Kwhr in the car.

I did the same calc going back home and got the lower 2.9 mile/kwhr when going above 80 for most of the trip.

Thank you for the details. It makes sense now. I don't use the miles remaining display but only SOC% because as you point out the miles remaining uses the EPA efficiency for its calculation. I probably would have done 209 miles/ (.69*92kWhr) = 3.3 mi/kWhr. The result is the same.

I am curious about the difference between the calculation and the since last charge number because I have not seen that type of discrepancy before.

 

[Andretex]

Thank you for the details. It makes sense now. I don't use the miles remaining display but only SOC% because as you point out the miles remaining uses the EPA efficiency for its calculation. I probably would have done 209 miles/ (.69*92kWhr) = 3.3 mi/kWhr. The result is the same.

I am curious about the difference between the calculation and the since last charge number because I have not seen that type of discrepancy before.

Thank you for the details. It makes sense now. I don't use the miles remaining display but only SOC% because as you point out the miles remaining uses the EPA efficiency for its calculation. I probably would have done 209 miles/ (.69*92kWhr) = 3.3 mi/kWhr. The result is the same.

I am curious about the difference between the calculation and the since last charge number because I have not seen that type of discrepancy before.

this is the picture from the first calc showing the "Since last charge" info. This is where I got the 3.5 m/kwh information. Your calc is about the same as mine of 3.3 m/kwh as you are assuming 69% vs the 71% I estimated.

If I look only at the "Last Charge" info, it shows I used up 59kwh. 59 of 92 total battery capacity is 64%. so 209 miles/.64 = 327 mile range or 77% of EPA 425 mile range. I wish we could get information with decimal places or just more information from the car. Getting 70% to 80% of the estimated range seems to be the correct result for a mixed city/highway drive.

 

[Bobby]

Do you know the speed used for EPA calc?

Highway is 48 average. https://en.m.wikipedia.org/wiki/FTP-75

 

[Andretex]

Highway is 48 average. https://en.m.wikipedia.org/wiki/FTP-75

wow. They should rethink that test. we can't even test 48mph on a highway without getting a ticket.

 

[joec]

wow. They should rethink that test. we can't even test 48mph on a highway without getting a ticket.

Yes. That's the EPA's testing guidelines, not Lucid. And it is fairly ridiculous.

 

[joec]

It helps to think of EPA as what the car could do, not what it will do. There are plenty of roads in America with 45 mph speed limits you can drive on for 400 miles and get EPA or even better. It really does depend on where you drive.

But it does set unrealistic expectations for those of us who spend a lot of time on highways with 75 or 80 mph speed limits.

 

[Adnillien]

View attachment 15080this is the picture from the first calc showing the "Since last charge" info. This is where I got the 3.5 m/kwh information. Your calc is about the same as mine of 3.3 m/kwh as you are assuming 69% vs the 71% I estimated.

If I look only at the "Last Charge" info, it shows I used up 59kwh. 59 of 92 total battery capacity is 64%. so 209 miles/.64 = 327 mile range or 77% of EPA 425 mile range. I wish we could get information with decimal places or just more information from the car. Getting 70% to 80% of the estimated range seems to be the correct result for a mixed city/highway drive.

I find it interesting that it shows 59kWhr used. Based on your information, your SOC went from 100% to 31% using 69% of the battery. 69% of 92kWhr is 63 kWhr. That 4 kWhr difference surprises me. You may want to email this to Customer Care and see how they respond. When I have sent Customer care information like this I get a message saying that email was forwarded to the engineering teams and then I never hear anything more.

 

[Derek O]

The first (higher) number was the trip computer from last charge. The lower m/kwhr I calculated by getting the total range I got divided by 92 kwhr battery.

One thing to consider is that, while the Touring does have a 92 kWh battery pack, my understanding is that it's about 88 kWh usable. That'll bump up your calculated miles/kWh figure to something much closer to what your car trip computer is telling you.

 

[Andretex]

One thing to consider is that, while the Touring does have a 92 kWh battery pack, my understanding is that it's about 88 kWh usable. That'll bump up your calculated miles/kWh figure to something much closer to what your car trip computer is telling you.

Good point. I did some research and could not find any concrete info on the usable part of the battery.

 

[Adnillien]

Good point. I did some research and could not find any concrete info on the usable part of the battery.

Your math implies the battery capacity is 86kWhr.

 

[DBV]

wow. They should rethink that test. we can't even test 48mph on a highway without getting a ticket.

Thanks for your information. It is very useful and appreciated.

Also - think it is crazy that EPA uses 48 mph as highway speed. Not sure where in the US would have that as the speed limit on a highway. Really wish Lucid and Tesla would use the other EPA rating system that the Euro’s use. Conservative is much better than overly optimistic.

 

[Ampere]

I named this thread, so I thought I'd add some additional input. I drove from a little NW of Champaign, IL to the Indianapolis Airport, about 260 miles r/t. No wind coming or going. Outbound temp was 75, return was 86. No passengers or cargo. I ran the AC on the way home. My average speed was about 71 mph (actually 73 on the speedometer, which is two mph optimistic). I charged to 97 percent and returned home with 22 percent remaining. The car reported 4.1 kwh/mile. Needless to say, I was very pleased.,
Incidentally, the Indy airport promises free 75 kw/hr charging if you pay to park in the garage. Unfortunately, no one enforces the 4-hour limit on the chargers. There are 14 chargers, half Tesla and half CCS. When I arrived, all the chargers were taken and there were no people with the cars. It seems that some folks just park, plug in and fly out. I asked parking garage attendants and even a police officer what the rules were and they just shrugged. FYI: There are no EA chargers near the airport and if you're coming from the west, all the EA chargers are on the north, east and south sides of Indy.

 

[Bobby]

Thanks for your information. It is very useful and appreciated.

Also - think it is crazy that EPA uses 48 mph as highway speed. Not sure where in the US would have that as the speed limit on a highway. Really wish Lucid and Tesla would use the other EPA rating system that the Euro’s use. Conservative is much better than overly optimistic.

Agree. The EPA needs to adopt a testing cycle that gives a realistic range for EVs. The cycle needs to be standard amongst all types of EVs. Until they do, manufacturers will use it to their advantages to quote range capabilities that are possible but unreasonable.