Performance not getting 310 miles promised

[DrDabbles]

Bought a P3D- in Aug 18. I get 292 miles on a fuel charge at a little over 200 whpm. In CA too. Mostly use seat heater on lowest setting and fan without ac or heat. But again Im near 200 wh/mi in traffic and still only see 296 showing on a full charge

74kWh battery pack, charged to 90% and depleted to 10% at 200 Wh/mi is 296 miles. So I'd say you're getting spot on what's advertised.

 

[AlanSubie4Life]

74kWh battery pack, charged to 90% and depleted to 10% at 200 Wh/mi is 296 miles. So I'd say you're getting spot on what's advertised.

I interpret this as 296 miles at 100%.

That implies that at 233Wh/mi (displayed) you can get 292 miles out of 100% to 0% charge (amount of energy above buffer is 296rmi*234Wh/rmi = 69.3kWh, full pack (clearly degraded) including buffer is of course 245Wh/rmi*296rmi = 72.5kWh, down from the original ~78kWh).

So that 69.3kWh spread over 292mi is 237Wh/mi. However, you miss a couple % on the trip meter (uncounted losses). So if you see 233Wh/mi displayed there it will use up your 69.3kWh over 292 miles (68kWh of which will show on the trip meter).

 

[ElectricGhost]

74kWh battery pack, charged to 90% and depleted to 10% at 200 Wh/mi is 296 miles. So I'd say you're getting spot on what's advertised.

No, thats at 100% charge. When it was new it showed 310 miles at 100% charge. So I have seen a 24 mile loss, while my driving efficiency has gone up a lot from like 350 to 200 wh per mile (new commute now has a lot of slow hwy grid lock traffic)

 

[ElectricGhost]

I interpret this as 296 miles at 100%.

That implies that at 233Wh/mi (displayed) you can get 292 miles out of 100% to 0% charge (amount of energy above buffer is 296rmi*234Wh/rmi = 69.3kWh, full pack (clearly degraded) including buffer is of course 245Wh/rmi*296rmi = 72.5kWh, down from the original ~78kWh).

So that 69.3kWh spread over 292mi is 237Wh/mi. However, you miss a couple % on the trip meter (uncounted losses). So if you see 233Wh/mi displayed there it will use up your 69.3kWh over 292 miles (68kWh of which will show on the trip meter).

Yes, and I have higher efficiency due to often 20-40 mph slow craw in hwy grid lock. I'm seeing closer to 215 wh per mile and still 100% charge shows 296.

 

[DrDabbles]

So I have seen a 24 mile loss

No you haven't. You've seen a poor display change its value. That number has no relation to the real world, just change to energy display and enjoy life with a % readout.

 

[AlanSubie4Life]

No you haven't. You've seen a poor display change its value. That number has no relation to the real world, just change to energy display and enjoy life with a % readout.

It’s possible there is some BMS confusion, but the displayed rated miles have a very direct correspondence with what the BMS thinks is energy remaining, which (if correct) has a very direct relationship with how far you can travel.

 

[DrDabbles]

It’s possible there is some BMS confusion, but the displayed rated miles have a very direct correspondence with what the BMS thinks is energy remaining, which (if correct) has a very direct relationship with how far you can travel.

The confusion that some owners appear to have is that the number on the main display relates to the actual miles they can drive. It does not, it relates to the state of charge multiplied by a fixed value. Because the number is expressed in miles (or km), every new owner appears to struggle with this same issue. The number displayed is not the mileage to expect from the battery.

And so, it is more useful and less confusing to look at the % (energy display). It more clearly expresses what the user should know. If the user would like to know how far they can travel given their previous 5/15/30 miles, then they should use the energy app with the full understanding that if the driving they're about to do doesn't match the driving they just did, that number also will not relate to reality.

This is the exact same situation as the MPG value and fuel gauge in a normal vehicle. The distance value on the battery display is a terrible UX, because it leads to these pointless 53 page threads where users don't understand what they're looking at, how it relates to the real world, or why they're so confused.

 

[AlanSubie4Life]

I certainly agree that people interpret the miles far too literally. And your recommendations are good ones (really, on a daily basis, I would recommend ignoring everything completely (including the energy consumption screen, %, and miles remaining), unless you are going on a trip or concerned about whether you have enough energy - in which case you should use the trip planner and ignore everything else - unless it is winter and extremely cold, in which case you should use your own neural net to assess your actual likely range).

that the number on the main display relates to the actual miles they can drive. It does not, it relates to the state of charge multiplied by a fixed value.

I will quibble with this:

1) The rated miles are not the SoC % multiplied by a fixed number. If it were, the two quantities would be equivalent. You cannot tell how much energy you have left when using SoC %. (Which is fine! It is just worth noting...)
2) For a given drive and vehicle type, the rated miles displayed is very directly correlated with how far one can travel on that drive before needing to recharge. So in that sense, it definitely relates to how far one can drive!

 

[MarcG]

1) The rated miles are not the SoC % multiplied by a fixed number. If it were, the two quantities would be equivalent. You cannot tell how much energy you have left when using SoC %. (Which is fine! It is just worth noting...)

I agree the “displayed rated miles remaining” number and the number calculated using some constant and SoC don’t match exactly, but I’m still not sure how Tesla plays with the numbers displayed (still waiting for my OBD2 adapter to play with SMT and figure it out for myself).

@AlanSubie4Life can you please point to a post summarizing the gimmicky things Tesla is doing to the displayed numbers?

 

[AlanSubie4Life]

(still waiting for my OBD2 adapter to play with SMT and figure it out for myself)

I think for you we already predicted it, but we can try to predict the SMT result if you want.

@AlanSubie4Life can you please point to a post summarizing the gimmicky things Tesla is doing to the displayed numbers?

Not sure which one you are speaking of. There is this post which links to the core data (two different posts), but I still need to do some updates for 2020 vehicles and constants. It’s a work in progress, but any user can trivially figure it out for their own vehicle (and in fact I would love to get some data from people with brand new 2020 vehicles to accurately measure the discharge “constant” prior to loss of capacity (to see if my theory verifies...).

 

[MarcG]

I think for you we already predicted it, but we can try to predict the SMT result if you want.

What I meant by the comment you quoted was that I haven’t figured out the formula Tesla uses to display rated range. I thought it was [full nominal pack minus 4.5%] divided by [some energy per mile constant] but your comments are making me think otherwise. Of course there’s also the early cap to display at most the EPA range for each model, which hides early degradation, but again I’m not sure how it all works exactly.

Not sure which one you are speaking of. There is this post which links to the core data (two different posts), but I still need to do some updates for 2020 vehicles and constants. It’s a work in progress, but any user can trivially figure it out for their own vehicle (and in fact I would love to get some data from people with brand new 2020 vehicles to accurately measure the discharge “constant” prior to loss of capacity (to see if my theory verifies...).

Thanks for the link! Sorry I can’t help you with 2020 data, but I’m sure others would be glad to in the name of science. I wish I had bought the ODB2 stuff and SMT the day I bought my car, oh well!

 

[AlanSubie4Life]

I thought it was [full nominal pack minus 4.5%] divided by [some energy per mile constant] but your comments are making me think otherwise

That is correct as I understand it - sorry my comments were misleading! For that formula the constant to use is 4.5% less than the charging constant though. (E.g. 234Wh/mi rather than 245Wh/mi). The charging constant can be used to provide quick predictions of full pack energy - any partial charge and if you use that constant you have to make adjustments if you want to predict current available energy (it’s a slope + offset formula).

Of course there’s also the early cap to display at most the EPA range for each model,

My belief explained elsewhere is this is not a cap in the strict sense - just a cap on the displayed value - they inflate every mile instead until the capacity drops below a certain value. There’s not a hidden “buffer” of energy above 310 miles for example - I think when the car is new and very energetic, each mile just contains more energy. And over time that comes down to a fixed value with no change in miles. Then miles start disappearing.

 

[MarcG]

That is correct as I understand it - sorry my comments were misleading! For that formula the constant to use is 4.5% less than the charging constant though. (E.g. 234Wh/mi rather than 245Wh/mi). The charging constant can be used to provide quick predictions of full pack energy - any partial charge and if you use that constant you have to make adjustments if you want to predict current available energy (it’s a slope + offset formula).

No worries! I'm still trying to wrap my head around all these formulas. I finally got the OBD2 stuff running and SMT shows my full nominal pack is 74.1kWh. So, I would expect the rated miles at 100% to be:

[ 74.1kWh * (1-0.045) ] / 0.234kWh/rmi = 302.42 rated miles

I charged to 100% on Sunday, and per the official Tesla API, my car reported exactly 302.04 rated miles. Which seems to indicate the formula is pretty close.

As for rated miles at other SoC levels, the screenshot from SMT below shows 37.1kWh "nominal remaining" capacity at 47.7% SoC (or 47.5% SoC expected, whatever that means).
However, 47.7% of 74.1kWh (my nominal full pack value) is 35.3kWh, NOT 37.1kWh. Obviously, taking the buffer into account would yield an even lower nominal remaining capacity value. And taking the expected SoC even lower.

So I'm not quite sure why there is such a discrepancy in values. At least this makes more sense: rated miles shown on the display were 144 at the time this screenshot was taken, which is 47.7% of the 302 rated miles I had at 100%.

Any insight you can share on this @AlanSubie4Life?

 

[AlanSubie4Life]

SMT below shows 37.1kWh "nominal remaining" capacity at 47.7% SoC (or 47.5% SoC expected, whatever that means).
However, 47.7% of 74.1kWh (my nominal full pack value) is 35.3kWh, NOT 37.1kWh.

SoC % = (Energy remaining above buffer) / (Energy remaining above buffer at full charge)

SoC % = (37.1 - 3.3) /(74.1 - 3.3) = 47.7%

I can't keep track of nominal remaining and expected remaining. I guess just use nominal remaining.

At least this makes more sense: rated miles shown on the display were 144 at the time this screenshot was taken, which is 47.7% of the 302 rated miles I had at 100%.

Yes that's basically the definition of SoC. Lots of ways to skin this cat, but you can calculate as:

Rated Miles Remaining = (kWhRemain - Buffer) / BMS Constant (This is equivalent to the formula you used above.)

Rated Miles = (37.1kWh-3.3kWh) / (234Wh/rmi) = 144.4 rated miles.

 

[MarcG]

SoC % = (Energy remaining above buffer) / (Energy remaining above buffer at full charge)

SoC % = (37.1 - 3.3) /(74.1 - 3.3) = 47.7%

Oooh that makes a lot more sense now. Somehow I thought the 37.1 was already excluding the buffer, but I guess my understanding was wrong... Thanks a lot!

 

[AlanSubie4Life]

Somehow I thought the 37.1 was already excluding the buffer,

No, it definitely does not. Easy to get confused by this, but now you know.

 

[Dan_LA]

I honestly don't want to keep dragging this post, but today I decided to check on the infamous "miles since last charge"... which I try to avoid to not get mad... and it's just insane, how on earth I am getting 130miles with 18% left... at 337 wh/mi? Like, I am not even getting 150 miles... no matter what math you guys pull out, pretty sure something wrong this car... Alan, I know you did a crazy math a while ago, and we agree that 220 miles was what I was getting at 100%... but this... it's a freaking joke I am getting the range of an BMW i3 Rex LR model...

After seeing a guy on YT driving out a new Model Y Performance with 21" wheel and doing 280 miles... I am thinking to make the switch... gonna be 3rd WW with wife changing for a 3rd Tesla in 3 years.

Just don't feel right getting an advertised 315 miles at the time (I know all the ifs by now)... and getting 50% of promised range. I call Tesla and they say I am driving over limit, that's all they can argue and say battery is fine... my a** is fine, pretty sure they put a 50 Kwh battery from the Short Range Model 3 by accident instead of a 75kwh. There is no other explanation. Guys that live close to me and go work, same damn car get 260miles range....

So many P3D+ owners here posting much higher range than me, and I don't think I am the only one that buys a Performance and drives like a performance... 75-85 ... occasionally kicks 90 mph.. and that's it... sometimes I try to coast at 70 mph in suburbs LA speed before a truck trying to run over me....

 

[Dan_LA]

No worries! I'm still trying to wrap my head around all these formulas. I finally got the OBD2 stuff running and SMT shows my full nominal pack is 74.1kWh. So, I would expect the rated miles at 100% to be:

[ 74.1kWh * (1-0.045) ] / 0.234kWh/rmi = 302.42 rated miles

I charged to 100% on Sunday, and per the official Tesla API, my car reported exactly 302.04 rated miles. Which seems to indicate the formula is pretty close.

As for rated miles at other SoC levels, the screenshot from SMT below shows 37.1kWh "nominal remaining" capacity at 47.7% SoC (or 47.5% SoC expected, whatever that means).
However, 47.7% of 74.1kWh (my nominal full pack value) is 35.3kWh, NOT 37.1kWh. Obviously, taking the buffer into account would yield an even lower nominal remaining capacity value. And taking the expected SoC even lower.

So I'm not quite sure why there is such a discrepancy in values. At least this makes more sense: rated miles shown on the display were 144 at the time this screenshot was taken, which is 47.7% of the 302 rated miles I had at 100%.

Any insight you can share on this @AlanSubie4Life?

View attachment 507839

Dude I've been in a cave, what;s this OBD2 and SMT thing... I need something to tell me my battery is 75kwh... because I believe I got the only Model 3 Performance with 50 kwh battery.

You are getting 302 range? I am getting 150 miles... same car!!

 

[MasterC17]

Dude I've been in a cave, what;s this OBD2 and SMT thing... I need something to tell me my battery is 75kwh... because I believe I got the only Model 3 Performance with 50 kwh battery.

You are getting 302 range? I am getting 150 miles... same car!!

I'm not sure you understand what is being referenced here. He is getting 302 miles of RATED range. It sounds like you are getting 150 miles of DRIVING range. In regards to your previous post, what battery % did you start with when you began your drive that (it sounds like) was 131.7 miles of straight driving?

The easiest way to increase range on the P3D+ is to get more efficient wheels (and more importantly) tires. The 20" Wheels with a summer Michelin are going to consume considerably more energy without question, compared to say 19's with a LRR tire.

Additionally, driving at 70mph, 75mph, 85mph, and 90mph are going to change your actual driving range by a massive amount. Aerodynamics over 55mph play a huge part in range, which is the same for every EV. E.g. Drag is proportional to the drag coefficient, frontal area and the square of vehicle speed. A Model 3 travelling at 120 mph has to fight with 4 times the drag of a Model 3 travelling at 60 mph.

Here's a great reference to drive these points home: Teslike.com

Additionally, it is impossible they installed the wrong battery pack for many reasons, one of which being the SR pack cannot deliver nearly enough energy for the Performance DU's (you would know if that was an issue), another that there is no connection point on the SR pack for the front DU, and that the car wouldn't even run with such a mistake as the BMS would freak out.

 

[DB-Cooper]

I honestly don't want to keep dragging this post, but today I decided to check on the infamous "miles since last charge"... which I try to avoid to not get mad... and it's just insane, how on earth I am getting 130miles with 18% left... at 337 wh/mi? Like, I am not even getting 150 miles... no matter what math you guys pull out, pretty sure something wrong this car... Alan, I know you did a crazy math a while ago, and we agree that 220 miles was what I was getting at 100%... but this... it's a freaking joke I am getting the range of an BMW i3 Rex LR model...

After seeing a guy on YT driving out a new Model Y Performance with 21" wheel and doing 280 miles... I am thinking to make the switch... gonna be 3rd WW with wife changing for a 3rd Tesla in 3 years.

Just don't feel right getting an advertised 315 miles at the time (I know all the ifs by now)... and getting 50% of promised range. I call Tesla and they say I am driving over limit, that's all they can argue and say battery is fine... my a** is fine, pretty sure they put a 50 Kwh battery from the Short Range Model 3 by accident instead of a 75kwh. There is no other explanation. Guys that live close to me and go work, same damn car get 260miles range....

So many P3D+ owners here posting much higher range than me, and I don't think I am the only one that buys a Performance and drives like a performance... 75-85 ... occasionally kicks 90 mph.. and that's it... sometimes I try to coast at 70 mph in suburbs LA speed before a truck trying to run over me....

View attachment 553875 View attachment 553876 View attachment 553877

Your math checks out, 300 mile range capacity. Let’s start:

• 131.7 miles divided by 44 kWh = 2.99 miles per kW
• 2.99 miles per kW multiplied by 75 kWh battery = 224.4 mile effective range
• 334 WH/mi divided by 250 WH/mil = 1.336
  • Tesla advertises M3 range based on 250 WH/mi
  • Performance models suffer 3% less rated range due to rims so it might be closer to 267 (see below)
    • 334 divided by 267 = 1.25
• 224.4 multiplied by 1.336 = 299.7 mile range based on YOUR data.
  • 224.4 multiplied by 1.25 = 281 mile range using more specific Performance targets (see below).

Tesla advertises Performance models to have 299 mile range. Non-Performance modes are rated at 322. So if you factor the 7% range loss to 250 WH/mile you get 267 WH/mile. At 267 against your data above, you still get 281 mile range (which is 94% of Tesla’s 299 claim). You definitely do not have a smaller battery pack or even a moderately degraded one. Early on, Tesla didn’t distinguish range differences due to wheels.

Things to consider:

• You will never use 100% of the battery, that’s literally 100%->0%
  • You used 44 kWh or 58% of your battery to go those 131.7 miles.
    
  • Non-driving still takes power, idle drain, Sentry, running Dog Mode, etc.
  • Max range is really only seen in highway long haul driving where the drain is effectively diminished.
• Your driving style requires 33% more energy than Tesla’s conservative figure of 250’ish WH/mi. This is comparable to a 20 mpg car getting only 15 mpg.
  
• High speed really hurts Tesla range, anything over 70 and you really take a penalty

Long story, your car is perfectly fine. All of this has been documented to death. Try to target 250-275 WH/mi and repeat some of the math above. Try to drive a charge not going over 65 or 70 mph just to test the math and high speed range considerations.