I know. They started doing this shady math now they have to stick with it. It would be interesting to see how other EV manufacturers calculate range.
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This is why you can't get 'rated range'
- Thread starter David99
- Start date
I know. They started doing this shady math now they have to stick with it. It would be interesting to see how other EV manufacturers calculate range.
They actually did and they have to! When running the EPA mandatory test cycle, the car has a certain energy consumption. All factors are defined, there is no room for variables or 'driving style'. That's the whole point of the EPA test cycle so consumers can compare consumption between vehicles. They all run the exact same test cycle and then the only difference is how much each vehicles consumes doing the exact same thing. They even give us that number right there on the energy graph. It literally says 'Rated'. That is what rated range is. Tesla says if you drive at the rated consumption the car has X amount of range. But that's a lie because they count down the miles faster than rated even when you drive rated so they end up at 0 when they have to shut down.
I have driven my car beyond zero miles several times. So have many others. So it seems Tesla allows you to discharge the battery a little more. Elon confirmed it in a tweet. It depends on how warm the battery is and, based on my experience, how hard or not you have been driving the car before you reach zero. I will do a test and see what the BMS says while doing it.
The trip planner seems to just calculate energy consumption based on data that Tesla has collected over the years. I don't think the rated consumption/range is even part of it. It only shows percentage, never 'rated miles'. I know it has been tweaked over the years. It used to be too optimistic, now it seems to be pretty spot on for me.
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It's always been known that Tesla's advertised range is determined by the EPA 5-cycle test. This test requires the vehicle to be driven until it has expended all energy and shuts down. For many of us, that would mean driving an unspecified number of miles past zero. In order to achieve rated range and not go past zero, I can't exceed around 280 Wh/mi in my P85. At any consumption higher than that I consume more rated range than miles driven.
I don’t doubt you guys get less than rated range at times. There are numerous threads on the subject. However, I often get better than rated on trips and around town. For example I drove to Cape Coral last weekend and back 190 miles each way. I started both trips with 238 miles in the battery and finished with 54-55 showing. That is 244 miles out of 238 starting. Today around town I started with 190 miles and made several stops. I drove over40 miles and had 160 left. Total 200 on a starting 190. Alldriving at the speed limit or above.
Last time I checked, and it was probably two decades ago, ICE fuel capacities included the gas in the fuel injection system and other fuel system plumbing that you could never actually use. I could never get anywhere close to the claimed capacity when filling up the tank. Seems like a precedent for Tesla there.
They did this on the 85s, 90s and some of the earlier 60s/70s. They all had usable (and even total) energy far less than the marketing number would seem to imply. They got a lot of flack for I believe they're pretty close now. In fact, I think the 100 actually has slightly more than 100 usable. That's why the 100D (539 km) has near 27% more the the old 85D (426km), despite that the marketing numbers say it should only be 18%. And the current 75Ds have 416km - not even 3% less than the old 85Ds.
For what it's worth, anybody buying one of these should look at the EPA rating and not the marketing number. I've found that I generally get close to range EPA in the summer. In the winter it's another story of course.
The 85 didn't have true 85 but the 60 has even a little more. The EPA numbers reflected that correctly. The labels did not match the true capacity. But again, that's actually not the issue. The issue is Tesla is using the total capacity rather than usable to estimate range but then secretly counts down faster to arrive at 0 miles.
I can hit that number if I don't go over 70 MPH on the freeway. I live in Arizona and don't have to contend with much inclement weather. Driving around town I can get into the 270s.
Are you sure about that? Where was that confirmed? The only discrepancies I'm aware of are between the marketing number and usable & total capacities.
hacer
Active Member
Except that the EPA sticker value requires that the consumption be measured from the input power during charging, not the (battery) output power during driving. Loss in the charging system and battery will mean that actual consumption from the battery must always be lower than the EPA value to achieve rated range. So in your "test" you were driving with an excessive consumption level which is why you don't get rated range.
I agree although i will never get close to your numbers. I don’t understand how anyone can average over 300 wh/mi and still keep a liscense. No wind my car hits 300 at about 80-85.I've found Ideal miles is closer to my real-world experience
dhrivnak
Active Member
I am glad they fixed this on the 3 as it appears easy to hit the rated range. I think for the 3 it is 230 Watts/mile which is not hard in that car at least with the Aero wheels.
You are confusing the 'rated range' and the consumption associated with it, and the MPGe number from the EPA. The number that the EPA publishes (and car manufacturers are required to put that on their sticker) is the MPGe (e stands for equivalent). That is consumption from the grid and converted back to gallons of gasoline.
Tesla is showing in car the energy consumed from the battery, not from the grid. The 295 Wh/mile is based on energy consumption from the battery, not from the grid. 'rated range' is the range in miles that the car can drive using the EPA test cycle. Based off that Tesla determined what the consumption is from the battery and shows that on it's energy graph. Heck when the car stops or is parked the energy consumption is not calculated by the car. The energy consumption shown in the car is totally cheating. It doesn't include vampire drain, it doesn't include stops and it doesn't include charging and battery efficiency losses.
Hmmm... I think you're seeing conspiracy where there is just complexity.
Without going under the hood to see what Tesla does, I can see calculation of remaining range to be a bit of a tricky business. Unlike with a fuel tank you can't measure the remaining energy directly. It has to be correlated with a non-linear voltage drop across the cells. And that correlation is going to vary with battery temperature, age of cells, and current discharge rate. A new battery, sitting in a parking lot at 12C at X volts will not have the same energy remaining as an older battery, at 35C, discharging 200 amps at X volts.
On top of that, people who are driving want to see a steady degradation of remaining range with each km driven. Even with all of the factors accounted for, I suspect that you can't pull that level of precision from the pack voltage - and so Tesla will have to do some numerical gymnastics, utilizing pack voltage along with distance travelled and a measure of energy discharged.
At most, remaining range is only ever going to be an approximation. I seriously doubt that Tesla is deliberately playing games to deceive the owner.
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