So Elon Says CR attained 350 actual miles

[ElectricIAC]

Well, this isn't exactly accurate. My wife's 2018 P3D+ with 12k miles still has 74.4 usable kWh with 3.3kWh reserve. Brand-new the pack has nearly 80kWh in total. And the EPA rating is of course based on a new battery pack.



I could be wrong, but I am fairly certain the G revision of the rear motor is what prompted the small efficiency increase. It's the only piece of hardware in the driveline I can find that changed and would make sense.

You’ve done a test to measure this for real? 100%-0% or at the very least a 90%-0%.

 

[MasterC17]

You’ve done a test to measure this for real? 100%-0% or at the very least a 90%-0%.

Good question! I did a 99%-4% a few weeks ago and consumed 67kWh, which means it had roughly 4kWh remaining until 0% when considering the 1% up top, but to your point that's only 71kWh. It may be 74.4kWh total with 3.3kWh of that being reserve, hmm?

@AlanSubie4Life is the best source for this information. According to his thread (2020, 2019, 2018 Model 3 Battery Capacities & Charging Constants), the P3D+ requires 239Wh/Mi to achieve 310 Miles of Rated Range, which insinuates the EPA rated range is based on a full battery pack size of 74kWh, which it seems when you account for the reserve it does indeed have.

 

[ElectricIAC]

70.5kWh (which puts it within earshot of the number I put out there)

A reserve may be present but how usable it actually is outside controlled testing is up in the air.

 

[AlanSubie4Life]

My wife's 2018 P3D+ with 12k miles still has 74.4 usable kWh with 3.3kWh reserve. Brand-new the pack has nearly 80kWh in total. And the EPA rating is of course based on a new battery pack.

74.4kWh means 304 rated miles at 100%. I will just take this datapoint as a given.

That 3.35kWh buffer is included in that 74.4kWh. So only 71kWh are available from 100% to 0%.

I did a 99%-4% a few weeks ago and consumed 67kWh, which means it had roughly 4kWh remaining until 0% when considering the 1% up top, but to your point that's only 71kWh. It may be 74.4kWh total with 3.3kWh of that being reserve, hmm?

Extrapolating this result gives 70.5kWh. (Which implies 70.5kWh/0.98 = 72kWh actually available from 100% to 0%.)

The trip meter only counts ~98% of that energy available from 100% to 0%.

So 71kWh*~0.98 = ~69.6kWh is the max I would expect to see on the trip meter for a full 100% to 0% discharge with your 74.4kWh assumption.

You might have seen 70.5kWh, perhaps, but it depends on rounding errors and also the accuracy of the 74.4kWh number we are assuming. Seems very close.

the P3D+ requires 239Wh/Mi to achieve 310 Miles of Rated Range, which insinuates the EPA rated range is based on a full battery pack size of 74kWh,

That 239-240Wh/mi number is the “initial trip meter constant” before any degradation. And that is the number on the trip meter - not the actual energy (yes it is confusing). And it assumes 79.3kWh capacity, and that you do NOT use any of the buffer. (79.3kWh*0.955*0.98/310mi = 239.4Wh/mi)

As the battery loses capacity, this trip meter discharge value plateaus at closer to 230Wh/rmi.

For 2018/2019: The EPA article achieved 310 rated miles with ~79.3kWh. So a 256Wh/mi result (which would display on the trip meter as 0.98*256Wh/mi = 251Wh/mi) would give you 310 miles (the EPA miles). But that is again, before capacity loss. And it assumes using all of the buffer.

However, once a P3D starts showing less than 310 rated miles, that means capacity is below 76kWh. (Before that, degradation is hidden, likely with more energetic rated miles - see the inflated constant of 239Wh/rmi discussed above.) So with that exact capacity, to get 310 miles from 100%-0% (on trip meter):

76kWh/310mi * 0.955 * 0.98 = 229.5Wh/mi

(Would show 71.1kWh on the trip meter.)

To get 310 miles, driving into the buffer and getting lucky enough to use it all without shutdown:

76kWh/310mi * 0.98 = 240Wh/mi

(Would show 74.5kWh on the trip meter.)

Again, both of those numbers are assuming a 76kWh battery according to SMT.

I realize it is confusing. Just keep in mind the trip meter reads about 2% low relative to SMT readbacks, from what I have seen (would be great to have really good data on this, but this is what I have observed from people’s posts). And it does line up with my observations.

 

[AlanSubie4Life]

From the long rages 3. I barely get 170 from my SR+

View attachment 514159

To be clear, the result being referenced here refers to a 2018 LR RWD, likely before the efficiency improvement.

If it was done on a new car in 2018, it is hard to say with the LR RWD (there has been a lot of confusion), but likely the available energy was about 76kWh (see first EPA test data). (They later made an additional 3kWh available and boosted range to 325 miles.)

So to get 350 miles, the trip meter would have displayed:

76kWh*0.98/350mi = 213Wh/mi

I am fairly sure people with LR RWD vehicles have been able to see this result without too much difficulty, if they limit their speed.

In this special case, the LR RWD today, assuming it shows 325 rated miles at a full charge (probably such LR RWD vehicles do not exist), would actually only need to get 221Wh/mi! If it shows 310rmi...means it has lost 3kWh capacity from the boosted 79kWh, is back to the original 76kWh...and needs to do 213Wh/mi on the trip meter to get 350 miles.

All of these numbers assume full use of the buffer - you drive until the car stops moving.

 

[DR61]

Because generally only obstinate Prius drivers drive under the limit on multi lane limited access freeways. Well, that and Model X drivers running on low.

Data? I typically see a majority of Prius drivers going much faster than the limit on freeways. Here is an interesting article about how speeds creep up significantly above the speed limit:
E Is for Embolden but Also Encourage • Driving in the Real World®