Rated vs Ideal vs Projected and how to use them

[GeekGirls]

I just got my car and am getting between 450 Wh/mile and 400 Wh/mile on my normal driving trips. This is much more than I expected also. I have noticed that hills are much rougher on energy usage than I imagined, and I do not have the hang of gauging my regen properly yet.

I don't think hills are as big a deal as I originally expected. My daily drive involves climbing 1500ft and descending again, both to and from work, plus incidental hills. It's not a high speed drive, so I manage to achieve better-than-EPA-rated efficiency on a frequent basis. My drive in this morning averaged 274wH/mi, which is even better than "ideal." I was using seat heat rather than forced air, and I almost never used the brake. Learning to rely on standard regen to slow the car is one key, but I also found turning off creep made a surprisingly large difference.

And apparently driving 85 sucks down 400+wH/mile even on flat stretches.

Air resistance increases with the square of velocity, so the amount of energy you use per mile overcoming air resistance has a linear relationship with speed. Tesla's 300mi ideal range represents about 283wH/mi at 55mph, so I'd expect numbers in the low 400s at 85mph.

 

[wycolo]

> The setting formerly allowing you to choose between Projected and Rated now lets you choose between Rated and Ideal. [brianman]

Goodbye Projected Range. R.I.P.

 

[ggr]

In earlier versions, there was: Projected, Rated, and Ideal.

With newer versions, Rated and Ideal are the only available choices for the "under the speedometer" battery meter.

The setting formerly allowing you to choose between Projected and Rated now lets you choose between Rated and Ideal.


I presume "Projected" is what you meant by "Estimated", so hopefully this is helpful.

OK, assume I change my terminology to "projected", I still can't get it to display on the instrument cluster... only on the big screen. That's what I care about.

 

[tomas]

Hypothesis regarding the whole range kerfluffle: If I had a new car company with a new fuel technology, and the largest fear of the buying public was range of this new technology, I would want to make sure that the primary range displayed on the dash was somewhat controlled by me, not by someone's aggressive driving habits, the subzero temps that day, or whatever. So, I'd show range as a fixed "approved" factor (such as what I'd tested it at under good conditions) and optionally show a secondary projected range based upon actual performance that day averaged over some distance.

As a driver, I might want something different, but since I have a huge stake in Tesla Motors success and I want to see the public get beyond EV range anxiety, I'm gonna just use the tools they gave me to calculate my expected range.

 

[brianman]

OK, assume I change my terminology to "projected", I still can't get it to display on the instrument cluster... only on the big screen. That's what I care about.

Right and we (at least a half dozen of us) moaned about this on the forum months ago. : |

- - - Updated - - -

Hypothesis regarding the whole range kerfluffle: If I had a new car company with a new fuel technology, and the largest fear of the buying public was range of this new technology, I would want to make sure that the primary range displayed on the dash was somewhat controlled by me, not by someone's aggressive driving habits, the subzero temps that day, or whatever. So, I'd show range as a fixed "approved" factor (such as what I'd tested it at under good conditions) and optionally show a secondary projected range based upon actual performance that day averaged over some distance.

As a driver, I might want something different, but since I have a huge stake in Tesla Motors success and I want to see the public get beyond EV range anxiety, I'm gonna just use the tools they gave me to calculate my expected range.

And this is where they have the opportunity to show that the customer comes first, rather than the PR.

They had a feature many of us preferred, and took it away from us. They gave us something different, and less useful than what we had.

For the instrument cluster.



The changes to the Energy App on the 17" I don't find troubling.

 

[dflye]

I'd be happy if it had an option to just display the kWh remaining in the battery (not taking into account any charge set aside for when you get to 0 miles of range).

That would be a consistently computed value, regardless of driving habits, it just declines with use, whether from driving or accessory use or battery warming or whatever else consumes watts.

 

[brianman]

I'd be happy if it had an option to just display the kWh remaining in the battery (not taking into account any charge set aside for when you get to 0 miles of range).

That would be a consistently computed value, regardless of driving habits, it just declines with use, whether from driving or accessory use or battery warming or whatever else consumes watts.

I've got a workaround for you:
1. Set your Rated/Ideal setting to Ideal
2. On post-it note #1, write "/4" and position it below the numeric portion of the range gauge below the speedometer
3. On post-it note #2, write "kWh" and position it so that it covers up the "mi." of the range gauge below the speedometer

You'll have to do the division by 4 in your head, but that'll get you a pretty decent guess at the kWh you have left in the tank.

 

[dflye]

I've got a workaround for you:
1. Set your Rated/Ideal setting to Ideal
2. On post-it note #1, write "/4" and position it below the numeric portion of the range gauge below the speedometer
3. On post-it note #2, write "kWh" and position it so that it covers up the "mi." of the range gauge below the speedometer

You'll have to do the division by 4 in your head, but that'll get you a pretty decent guess at the kWh you have left in the tank.

Doh, too true! I feel like I'm in that comic strip where Mr. Obviousman flies in and saves the day.

I guess I'd rather have the number of kWh that requires mental computation vs some number of miles that the Neanderthal part of my brain reads early in a long trip as meaning "Durrh, you have plenty of range, floor it!" and then I get stuck limping into some Nissan dealership in the middle of the night on the way home as there isn't diddly-squat other than that for the non-metropolis parts of NC.

 

[brianman]

Doh, too true! I feel like I'm in that comic strip where Mr. Obviousman flies in and saves the day.

Hehe. It's fun playing that role, but it doesn't pay well and tends to .. not .. win friends and influence people.

 

[ggr]

I've got a workaround for you:
1. Set your Rated/Ideal setting to Ideal
2. On post-it note #1, write "/4" and position it below the numeric portion of the range gauge below the speedometer
3. On post-it note #2, write "kWh" and position it so that it covers up the "mi." of the range gauge below the speedometer

You'll have to do the division by 4 in your head, but that'll get you a pretty decent guess at the kWh you have left in the tank.

Yeah, pity there isn't a computer in there somewhere that could do the computation for us...

Oh. Yeah.

 

[Norbert]

The "custom efficiency factor"...

 

[brianman]

The "custom efficiency factor"...

I should probably formally follow-up with Tesla. Something like...

• Tesla Service, how can I help you?
• This rated range thing isn't working out for me. I keep risking warranty violations because I'm pretty close to zero miles whenever I go on a trip...anywhere.
• Hm. Why do you say it's a "rated" range problem?
• Because you took away my Projected range setting for the instrument cluster.
• You mean the Rated range is hard for you to obtain? What's your lifetime Wh/mi.? It can't be that different...
• 426 Wh/mi.
• No, not when you're going uphill in the wind and stuff...your average. Whichever of your trip meters has the longest distance. What does that one say?
• Yah, both my trip meters were zero'd when I took delivery and have never been reset. 426 Wh/mi.
• Oh.
  (pause)
• Yah, so can we get a setting or something to control the scale factor used for the range meter below the speedometer?
• I'll pass that request up the chain.
• Thanks. BTW, love the Perf. Wouldn't trade it even if the instrument cluster's range meter was invisible. Cheers.
• Heh. Ok, I'll pass that up too. Have a good night.

 

[bonnie]

I should probably formally follow-up with Tesla. Something like...

• Tesla Service, how can I help you?
• This rated range thing isn't working out for me. I keep risking warranty violations because I'm pretty close to zero miles whenever I go on a trip...anywhere.
• Hm. Why do you say it's a "rated" range problem?
• Because you took away my Projected range setting for the instrument cluster.
• You mean the Rated range is hard for you to obtain? What's your lifetime Wh/mi.? It can't be that different...
• 426 Wh/mi.
• No, not when you're going uphill in the wind and stuff...your average. Whichever of your trip meters has the longest distance. What does that one say?
• Yah, both my trip meters were zero'd when I took delivery and have never been reset. 426 Wh/mi.
• Oh.
  (pause)
• Yah, so can we get a setting or something to control the scale factor used for the range meter below the speedometer?
• I'll pass that request up the chain.
• Thanks. BTW, love the Perf. Wouldn't trade it even if the instrument cluster's range meter was invisible. Cheers.
• Heh. Ok, I'll pass that up too. Have a good night.

You're using sock puppets to act this out, aren't you?

 

[brianman]

You're using sock puppets to act this out, aren't you?

No, but great idea!

 

[dtich]

No, but great idea!

yeah, great scene, but... i don't really see how you have such a big problem and are getting to 0 miles. look at your rated range. look at your actual miles driven. do 300ms of mental math and get a good idea of how much battery you use compared to the stated range. works. projected can help you plan. where's the issue? really?

 

[brianman]

The issue is distance planning. Rated miles are just as fantasy as Ideal for me lately.

It's weather combined with non-flat terrain, neither of which are really "adjustable" to the point where even at cruise control @ 55mph you can't trust the range indicator. And, no, the answer isn't "drive 35 mph on a 60 mph freeway". Not for me at least.


And I didn't say it's a big problem, just that it's a self-inflicted degradation in the Model S offering -- newer firmware is worse for the customer than older firmware. One of the core philosophies of the upgrade process for Tesla vehicles should be that a newer firmware version should be equal to or better than the previous version. In this particular aspect, they took a step backwards. The size of the step backwards is less the point, than the direction of the step.


Edit: Additional note...
When the "Projected is gone from the instrument cluster" was first reported, it made me seriously consider not upgrading the firmware. I eventually just plodded forward anyway, but any feature change that makes people consider not wanting your newest firmware should be a warning shot that you made a questionable decision.

 

[Todd Burch]

The Energy app shows projected range over 5, 15, or 30 miles.

The console battery meter must do it for the entire battery energy remaining.

Perhaps--just maybe--they took it out temporarily to work on the algorithm and improve it. For example, we know when the pack's cold reported range is less than actual. Maybe they realized the existing algorithm would give people a false sense of security and took it out until they could correct it?

 

[dsm363]

You're using sock puppets to act this out, aren't you?

........And scene!

 

[PatP]

The issue is distance planning. Rated miles are just as fantasy as Ideal for me lately.

It's weather combined with non-flat terrain, neither of which are really "adjustable" to the point where even at cruise control @ 55mph you can't trust the range indicator. And, no, the answer isn't "drive 35 mph on a 60 mph freeway". Not for me at least.

And I didn't say it's a big problem, just that it's a self-inflicted degradation in the Model S offering -- newer firmware is worse for the customer than older firmware. One of the core philosophies of the upgrade process for Tesla vehicles should be that a newer firmware version should be equal to or better than the previous version. In this particular aspect, they took a step backwards. The size of the step backwards is less the point, than the direction of the step.

Imagine how useless rated is for me: I'm at an average of 540 wh/miles since I got the car. Try explaining to your wife you have to cut your rated miles in half.

I think we're not helping Tesla when we say this not important and that you just have to do the math in your head... For normal people (non early adopter) it is. My wife Volt's auto adjust the range so you can trust the big projected range display - this is what people expect. In an electric only car you need to be ultra conservative on range - quite the opposite of what Tesla is doing right now.

 

[FlasherZ]

It's a damned-if-you-do, damned-if-you-don't situation.

I consume ~425-450 Wh/mile on 10 mile trips to the local town (store, bowling alley, post office, etc.) because of my 2 mile multi-hill, multi-turn route to the highway. I consume ~325 Wh/mile on 100 mile shopping trips to the "local" shopping metroplexes. Projected was just as meaningless to me.

I use "rated" as a relative fuel gauge. I'd be happy to solve this argument by changing the "rated miles" to % of battery left.