Photo: Tesla
As Tesla announced changes to its lineup for the 2024 model year, many were surprised to see that most of its models were listed with lower EPA range estimates than before. The reason is more benign than what the sensationalist media claimed and has nothing to do with Tesla in the first place.
Fuel consumption and energy efficiency have always been contentious for car buyers, mainly because few understand how they are calculated and why. Many take the numbers as absolute truth and demand they be as accurate as possible in real-world driving. This has only been exacerbated in the EV era, as electric cars are more sensitive to driving style changes than their ICE counterparts.
To start with the first part, the EPA estimates, and any other consumption and efficiency estimates, are not calculated in real-world conditions. Nobody drives the respective vehicles to see how the consumption varies with city driving, highway driving, wind, cold, and other variables that might affect them. Instead, the tests are done in the lab and on the dyno by simulating real-world conditions.
If they are not meant to tell you how much fuel (or electricity) a car consumes, then what purpose do they serve, you might ask? Although it's much more complicated than that, the main reason is to allow car buyers to easily compare various car models from a consumption standpoint. Ideally, since these testing conditions are standardized, you exclude subjective factors like driving style from the calculations, and all would be equal.
The EPA ratings are today more accurate than before, but they are still subject to manipulation by companies. This is why every time a driver sees that he can't achieve the manufacturer's claimed consumption, he thinks the carmaker faked the numbers. This is even more so with electric vehicles, although there are wild variations among different brands. For instance, many German brands score poorly in the EPA range estimates, which makes the results appear more accurate in real-world driving.
As I have conducted many range tests myself, I know how hard it is to have a driving style that results in fuel/energy consumption that comes even close to specifications, let alone beat it. Inflate the tires to the maximum safe value, drive slowly, touch the accelerator like it's made of butter, and do whatever you want, but don't break because accelerating back would ruin the average figure you worked so hard to achieve.
As I said, EVs are especially sensitive to changes in driving conditions and style because they use very little energy compared with ICE vehicles. A Tesla Model 3 has a 75-kWh battery. For comparison, one gallon of gas has 33.7 kWh based on the EPA formula. That means that an electric vehicle must be as efficient as possible because its "tank" has only two gallons of gas (compared to over 13 gallons in a Toyota Corolla). Small changes in drivers' behavior, road conditions, wind, and others can throw the numbers all over the place.
This is why people tend to be even more sensitive to EPA range estimates and energy efficiency in electric vehicles. And because electric vehicles are far more powerful beasts than their ICE counterparts, most people, especially those coming from a gas-powered vehicle, tend to drive them hard and fast. This is sure to deplete the battery in no time, especially as the energy available is not that much to begin with.
Now, this caused a series of sensationalist headlines across the board, with some news outlets stating that Tesla was "forced" to lower range estimates "following exaggeration complaints" and a DOJ investigation into this matter. The truth is more benign than these headlines suggest. In fact, the change is not only affecting Tesla but every carmaker selling electric vehicles. It's just that Tesla was among the first to start selling the 2024 model year EVs tested under the new conditions.
The carmakers have been notified of the changes in the EPA test procedures in a letter shared by the agency in July 2023. According to this (attached below), the results take into account various drive modes available to the driver, including acceleration/performance modes as well as ride height modes. Specifically, the testing must be done in both best- and worst-case scenarios, which leads to a perceived loss in efficiency and increased energy consumption. This is aimed at bringing EPA estimates closer to what an average driver might experience during everyday driving.
As I've written in an earlier article, this led to EPA range estimates for most Tesla models to drop by up to 37 miles. Not all models are affected, which might be puzzling for some people. For starters, no Model 3 variant has seen a decrease in range. That's because Tesla has not tested the baby electric sedan for the 2024 model year. It might never do it, considering that the refreshed Model 3 is around the corner. Some rumors indicate that it might be announced by the end of January.
Also, in the case of the Tesla Model S, the Long Range model doesn't appear to be affected. This is not the case, though. To maintain its record 405-mile range rating, Tesla had to lower the maximum speed from 155 mph to 130 miles. The Model S Plaid, on the other hand, lost between 28 and 37 miles, supposedly because its famous Plaid mode is now affecting the results. The Model Y variants lost less range (up to 20 miles) after Tesla removed two less favorable stopping modes (Creep and Roll) and kept only the most energy-efficient mode (Hold).
To start with the first part, the EPA estimates, and any other consumption and efficiency estimates, are not calculated in real-world conditions. Nobody drives the respective vehicles to see how the consumption varies with city driving, highway driving, wind, cold, and other variables that might affect them. Instead, the tests are done in the lab and on the dyno by simulating real-world conditions.
If they are not meant to tell you how much fuel (or electricity) a car consumes, then what purpose do they serve, you might ask? Although it's much more complicated than that, the main reason is to allow car buyers to easily compare various car models from a consumption standpoint. Ideally, since these testing conditions are standardized, you exclude subjective factors like driving style from the calculations, and all would be equal.
Why the EPA ratings don't equal real-life consumption?
That would probably be true if we lived in an ideal world, but in ours, the ideal is impossible to achieve. For starters, the consumption is not tested by independent bodies. Instead, the carmaker does the testing and submits the results to the EPA and other regulators for approval. Since there are incentives to advertise the lowest consumption, the carmakers will pull all the tricks in the book to lower the results as much as possible.The EPA ratings are today more accurate than before, but they are still subject to manipulation by companies. This is why every time a driver sees that he can't achieve the manufacturer's claimed consumption, he thinks the carmaker faked the numbers. This is even more so with electric vehicles, although there are wild variations among different brands. For instance, many German brands score poorly in the EPA range estimates, which makes the results appear more accurate in real-world driving.
As I have conducted many range tests myself, I know how hard it is to have a driving style that results in fuel/energy consumption that comes even close to specifications, let alone beat it. Inflate the tires to the maximum safe value, drive slowly, touch the accelerator like it's made of butter, and do whatever you want, but don't break because accelerating back would ruin the average figure you worked so hard to achieve.
As I said, EVs are especially sensitive to changes in driving conditions and style because they use very little energy compared with ICE vehicles. A Tesla Model 3 has a 75-kWh battery. For comparison, one gallon of gas has 33.7 kWh based on the EPA formula. That means that an electric vehicle must be as efficient as possible because its "tank" has only two gallons of gas (compared to over 13 gallons in a Toyota Corolla). Small changes in drivers' behavior, road conditions, wind, and others can throw the numbers all over the place.
This is why people tend to be even more sensitive to EPA range estimates and energy efficiency in electric vehicles. And because electric vehicles are far more powerful beasts than their ICE counterparts, most people, especially those coming from a gas-powered vehicle, tend to drive them hard and fast. This is sure to deplete the battery in no time, especially as the energy available is not that much to begin with.
New EPA test procedure for MY2024 EVs
Because so many people complain about fuel and energy consumption figures not being accurate, regulators are constantly making changes to their testing procedures to make the results more aligned with what regular people see in real life. In the case of the EPA, the latest change entered into effect for the 2024 model year electric vehicles. Tesla was among the first carmakers to list the new estimates, and, as expected, they were lower than before.Now, this caused a series of sensationalist headlines across the board, with some news outlets stating that Tesla was "forced" to lower range estimates "following exaggeration complaints" and a DOJ investigation into this matter. The truth is more benign than these headlines suggest. In fact, the change is not only affecting Tesla but every carmaker selling electric vehicles. It's just that Tesla was among the first to start selling the 2024 model year EVs tested under the new conditions.
The carmakers have been notified of the changes in the EPA test procedures in a letter shared by the agency in July 2023. According to this (attached below), the results take into account various drive modes available to the driver, including acceleration/performance modes as well as ride height modes. Specifically, the testing must be done in both best- and worst-case scenarios, which leads to a perceived loss in efficiency and increased energy consumption. This is aimed at bringing EPA estimates closer to what an average driver might experience during everyday driving.
As I've written in an earlier article, this led to EPA range estimates for most Tesla models to drop by up to 37 miles. Not all models are affected, which might be puzzling for some people. For starters, no Model 3 variant has seen a decrease in range. That's because Tesla has not tested the baby electric sedan for the 2024 model year. It might never do it, considering that the refreshed Model 3 is around the corner. Some rumors indicate that it might be announced by the end of January.
Also, in the case of the Tesla Model S, the Long Range model doesn't appear to be affected. This is not the case, though. To maintain its record 405-mile range rating, Tesla had to lower the maximum speed from 155 mph to 130 miles. The Model S Plaid, on the other hand, lost between 28 and 37 miles, supposedly because its famous Plaid mode is now affecting the results. The Model Y variants lost less range (up to 20 miles) after Tesla removed two less favorable stopping modes (Creep and Roll) and kept only the most energy-efficient mode (Hold).
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