# Range.... do we REALLY ever know what's real?



## Power Surge (Jan 6, 2022)

So this thought has crossed my mind before, but more so now after the latest updates. 

Do we really ever know true range and battery usage? These are numbers that are calculated by the car's on board computers and electronics. And these computers and electronics are constantly "updated" by Tesla. Which means Tesla pretty much has infinite control over the data you get back from your car. 

Who's to say that Tesla doesn't alter these numbers to hide battery degradation as cars get older to avoid having to warranty batteries? Or for many other various reasons? I think we all know that we don't get actual range shown vs charge state. I think that's more of a battery health indicator. But even still, Tesla has control over all these calculated numbers related to range and battery charge. 

Thoughts?


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## Ed Woodrick (May 26, 2018)

I absolutely agree with you. The batteries are actually capable of 9,432 miles and Tesla has limited them and is planning on opening them up in a few years.


Maybe someone has actually measured the capacity of the batteries and done the math.

And maybe it is a well-known fact that the battery management system can get out of whack and lie to you. 
And maybe it is a well-known fact that the range of the battery changes with speed and temperature (and a myriad of other things)

And knowing batteries, I know that it you actually measure the complete range, you stress the battery significantly, which is why Tesla has some bottom limits.


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## Power Surge (Jan 6, 2022)

Ed Woodrick said:


> I absolutely agree with you. The batteries are actually capable of 9,432 miles and Tesla has limited them and is planning on opening them up in a few years.
> 
> 
> Maybe someone has actually measured the capacity of the batteries and done the math.
> ...


No need to be a smart ass 

My point was that Tesla still has control over what we see on the screen, and has the capability to alter that.


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## garsh (Apr 4, 2016)

Power Surge said:


> Who's to say that Tesla doesn't alter these numbers to hide battery degradation as cars get older to avoid having to warranty batteries?


I understand the concern. In fact, I'm pretty sure that Nissan pulled this "hide the battery degradation" trick with a "mandatory software update" for my 2012 Nissan Leaf. I missed getting a new battery under warranty by a single "battery health bar".

As far as Tesla is concerned, there are many technically-inclined people who investigate the software, and many who examine and re-use batteries from old and damaged cars. And when Tesla tries to make a change that people believe is not kosher, They let Tesla have it (example). I feel pretty confident that Tesla is completely above-board in the battery capacity estimates, and that all of the updates they're performing really are geared towards increasing the accuracy of the measurements. But when they do try to change something that's not beneficial to the user, I'm even more confident that there are plenty of people out there who can detect it and will hold them accountable.


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## Madmolecule (Oct 8, 2018)

Although even when we get the data from OBD, it is still coming from Tesla through calculated by their firmware. The biggest problem I see If you can’t get service anywhere else, so you have to believe what Tesla is telling you. Also by trying not to get below 20%, and not charging over 80%. It makes it difficult to track this, and to know what is really the usable range for your Tesla in varying conditions. One of the biggest criticisms I’ve seen of the Rivian, Is that once someone has gotten used to living with a Tesla, range, just from experience, when they have to go to the Rivian calculated reange and it’s charging network they have a lot of the anxiety that people have Tesla . I know my model three cannot adjust for a trailer for example. It’s for estimating even during the drive resulted in the need to be towed.

I know I cannot rely on what the theoretical range is, But electrical vehicles are very different than ice vehicles, only from that we have a lot more experience on range and fuel economy on an ice vehicle. The manufacturers all try to hide the true information, this just does not make it very easy for the consumer to operate their vehicles most efficiently

I would prefer range regulation instead of emission regulation


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## tivoboy (Mar 24, 2017)

I recently did about 1400 miles up and down I5 to Oregon from the Bay Area and back. Lots of long inclines going from 0 to 3000 ft, then down a bit, then up to 4500 ft, then down a bit, over and over.. both heading north and of course coming south. EV trip planner indicates about 14000 ft elevation change UP going north with 13800 ft elevation change going north.. so essentially overall start and end at ~ same elevation.

Trip south is of course same, but the long run from about Yreka to the Bay Area is more like a very long slow drawn out downhill. 

My 2018 LR M3 still shows about 313 when fully charged..meaning charged and left on the wall charger for a good 45 minutes after what full charge would indicate. I’m pretty happy with that current level after 4+ years and 24K miles overall. 

Now, I tend to drive pretty fast on major highways, at ~80-83, which some small spikes to maybe 88 and only going down to 70-75 when traffic conditions indicate. I’m usually doing about 10-12 MPH over a posted speed. When I track, clock and calculate this out I end up averaging ~73 MPH overall for a three hour stint. With starts, stops and beginning and end and variation in traffic/police flows. I always tell people if you want to AVERAGE 75, you’ve got to be traveling 80+ for much of the time. 

The Tesla mapping systems knows the vehicle, the overall altitude changes, posted speeds on highway, battery capacity, POSSIBLY what battery degradation has occurred and currently nothing more is really included. ABRP allows for putting in things like additional vechicle weight, more than 1 person in the car, extra weight in baggage, how much faster do you drive than regular flow (which i interpret as above posted limit), wind, temp inside and out, etc. EV trip planner does some of this but not all. 

They all produce somewhat different results, obviously the more inputs one has and if they are not fully accurate the more damaged the OUTPUT can become. 

The one that really DOES end up being the closest is the IN CAR consumption and trip range estimate.. In the 3.25 legs I did heading each way north and south, after driving a while, the % SOC anticipated at the next supercharger was within 1-2% of the ACTUAL final SOC when I arrived nearly each time. The only time it was more than 5% off was in a southbound leg when I was in more traffic and following another car and doing a LOT of purposeful regen braking and so I arrived with 5% MORE SOC % than the Tesla had either initially or during projected.

My last point is that my overall w/m results also tend to land pretty much exactly where the car thinks they are. My average is right around 240 w/m overall. If I take the ~75 KW in the pack and do that math I get a range projection of 312 miles - compared to what the car indicates as 313. Certainly when going uphill this can be triple that and going downhill it can be negative QUADRUPLE. And this is with me nearly always traveling between 72-82 mph on the main highways.

I think the Tesla range calculations are going to be based on posted speeds or some flat 65 mph main highways, with some upping and downing thrown in. 

I am CERTAIN, 100% that If I had a relatively flat section of highway somewhere, managed to travel at 65 mph mostly, wasn’t doing 65 in cabin temp while the EXTERNAL temp was 100+, I am certain that the car would go 311-320 miles EASY without giving up the ghost. 

I’m looking forward to things like TIRE PRESSURE, maybe additional weight options, external temp, external wind, being added to the calculation but I’d like to see some others available to even better the range estimate.. but for now, I’m still pretty confident in the final number that the car is indicating.


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## Harvela (4 mo ago)

I have a 2021 S and travel back and forth from San Diego to Phoenix about 5 times a year. Outside of a couple of 4000' elevations the road is pretty flat (route 8) most of the way. I charged up to 400 miles to start the trip and when calculated the efficiency I am ending up about 70% which means that on a full charge I will get about 280 miles. My average speed on this trip is about 70MPH. Is this normal?


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## FRC (Aug 4, 2018)

Yes. You would need to average 50-55mph to approach your rated range. Just like you would have to travel at those speeds in an ICE car to get close to the rated mpg.


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## DocScott (Mar 6, 2019)

By the way, another big factor in getting the rated range that I don't see discussed as much: braking vs. regen. 

If I drive the way I used to in an ICE car, I'd use the brakes a lot. And, weirdly, so does TACC. If I anticipate places I'll need to slow down a bit more in advance, and just take my foot off the accelerator (if not on TACC) or use the thumb wheel to lower the speed (if on TACC), my efficiency is greatly improved. For a mix of highway and local driving in shirt-sleeve weather, I find doing that improves efficiency by about 20%.


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## Ed Woodrick (May 26, 2018)

DocScott said:


> By the way, another big factor in getting the rated range that I don't see discussed as much: braking vs. regen.
> 
> If I drive the way I used to in an ICE car, I'd use the brakes a lot. And, weirdly, so does TACC. If I anticipate places I'll need to slow down a bit more in advance, and just take my foot off the accelerator (if not on TACC) or use the thumb wheel to lower the speed (if on TACC), my efficiency is greatly improved. For a mix of highway and local driving in shirt-sleeve weather, I find doing that improves efficiency by about 20%.


Are you sure that TACC does? Or do you say that just because it feel like it? I think that it's using regen myself, which feels like braking.


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## DocScott (Mar 6, 2019)

Ed Woodrick said:


> Are you sure that TACC does? Or do you say that just because it feel like it? I think that it's using regen myself, which feels like braking.


Yes, I'm sure. It certainly doesn't always use brakes, but there's at least one specific (and common) situation where it does:

On a limited access highway, going at the speed I have set (say, 57 mph). Traffic slows a bit ahead. TACC generally assumes that the slowing is very temporary, and that the car that's slowed down will speed back up by the time I get to it. Sometimes, it's right! And when everyone has driver assist, systems assuming that will greatly reduce the rate of traffic jams that appear for no apparent reason.

But often, TACC's gamble ends up wrong. And so by the time TACC decides it has to slow, it's a bit too close to rely on regen alone, and blends in brakes.

This also happens when I'm on a major road that's almost a limited-access highway but has occasional stoplights. (We have some of those in the New York area. Yes, they're kind of weird.) TACC is just sure that the line of cars stopped up ahead aren't going to stay stopped; it doesn't seem to grok that they're stopped for a red light. So it decides to stop pretty late, and definitely needs to blend brakes in. Using the scroll wheel really helps in those situations.


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## Ed Woodrick (May 26, 2018)

DocScott said:


> Yes, I'm sure. It certainly doesn't always use brakes, but there's at least one specific (and common) situation where it does:
> 
> On a limited access highway, going at the speed I have set (say, 57 mph). Traffic slows a bit ahead. TACC generally assumes that the slowing is very temporary, and that the car that's slowed down will speed back up by the time I get to it. Sometimes, it's right! And when everyone has driver assist, systems assuming that will greatly reduce the rate of traffic jams that appear for no apparent reason.
> 
> ...


I'm not sure why you think that limited access roads with traffic lights is rare, in my experience, they are pretty common. If they don't have traffic lights, then they are generally Interstates.

But I'm still not sure how you _know_ that brakes are being added. I know that if I'm going 57 mph and remove my foot from the accelerator, the car is going to effectively slam my passengers into the dash, never having touched the brakes.


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## garsh (Apr 4, 2016)

Ed Woodrick said:


> But I'm still not sure how you _know_ that brakes are being added. I know that if I'm going 57 mph and remove my foot from the accelerator, the car is going to effectively slam my passengers into the dash, never having touched the brakes.


Try it - use TACC and approach stopped cars. You'll feel it slow down more quickly than full regen.


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## DocScott (Mar 6, 2019)

Ed Woodrick said:


> But I'm still not sure how you _know_ that brakes are being added. I know that if I'm going 57 mph and remove my foot from the accelerator, the car is going to effectively slam my passengers into the dash, never having touched the brakes.


Simple: rest your foot lightly on the brake pedal (but not enough to brake). When TACC adds brakes, it depresses the brake pedal.


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## DocScott (Mar 6, 2019)

Ed Woodrick said:


> I'm not sure why you think that limited access roads with traffic lights is rare, in my experience, they are pretty common. If they don't have traffic lights, then they are generally Interstates.


I don't think there's a really consistent definition for what a limited-access highway is. (A quick Google search shows up several different definitions, partly dependent on what state they're in...some definitions suggest no traffic lights.)

To me, I expect a limited-access highway to skip possible intersections; that is, frequently go over crossroads using overpasses or having crossroads go over them using overpasses. Most typically, I expect when there is access to a crossroad that there are onramps and offramps and marked and numbered exits. There may be stoplights at the end of the offramps, but not ones that stop all the traffic on the road.

We have _lots_ of roads like that around here that aren't interstates; they're commonly referred to as "parkways." (I know "parkways" can mean something else in other parts of the country.) Look at a map of Westchester County, New York, for example, and check out the Sprain Brook Parkway or the Hutchinson River Parkway. They're not interstates and are not themselves numbered, but they're only accessed onramps and offramps; I don't think there's a stoplight along the whole length of either.

We do have some parkways that are a bit more of a hybrid, though; mostly onramps and offramps, and a lot of crossroads that are skipped using overpasses and underpasses, but once in a while a crossroad at grade that uses a stoplight. The Bronx River Parkway is of that variety.


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## Mr. Spacely (Feb 28, 2019)

Not just a guess or feeling, sometimes I can hear the brake pedal being moved...


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