Tesla revised its range estimates for its electric cars as US regulators prepare new rules to ensure automakers accurately reflect the performance of their cars in real-world driving conditions, Reuters reported.

The Elon Musk-led company is known for re-evaluating its car lineup, which has drawn numerous customer complaints over the years.

A large-scale investigation published by Reuters last summer found that about a decade ago, Tesla engineers tampered with the algorithm that controls the cars’ head-up display, which shows how much fuel is left before drivers need to stop to recharge the battery.

The same investigation also found that the electric car maker created a secret team in 2022 to mislead thousands of customers about complaints about the autonomy of Tesla cars they bought.

Many drivers consider autonomy to be the “Achilles heel” of electric cars

In an October financial report, Tesla said that federal investigators in the United States wanted it to provide information about the autonomy of the cars it produces.

The increased driving range is a major benefit for Tesla and other electric car makers in the United States, where drivers cite the lack of adequate battery charging infrastructure as the main reason they still prefer traditional cars.

Reuters has now discovered that Tesla’s official website shows lower range estimates for various variants of the Model X, S and Y, as well as 3 other cars the company makes.

While it’s not entirely clear when Tesla made the change, Reuters confirmed it by comparing estimates posted on the US Environmental Protection Agency’s (EPA) website, which has yet to update them. Automakers are required by US law to submit these estimates to the EPA.

Tesla revised its range estimates after new rules took effect in the US

For example, Tesla’s website currently lists the Long Range version of the Model Y as having a range of 310 miles (499 kilometers), while the EPA’s website lists it as having a range of 330 miles (531 kilometers).

For the Performance variant of the Y model, a crossover SUV, the range estimate has been reduced from 303 miles (487 kilometers) to 285 miles (458 kilometers).

Reuters notes that it could not be determined whether Tesla has changed its range estimates for every variant of every car model it makes.

New rules imposed by the EPA force automakers to test the range and efficiency of their electric vehicles in the “default” driving mode, the mode the car uses when the driver starts the engine. Many electric car models, including Tesla, have a number of driving programs for maximum performance.

If an EV doesn’t have a “default” or standard driving schedule, then EPA regulations require automakers to test the cars in their best and worst performance conditions and then average them.

The rules were outlined by the EPA in a July 2022 letter to automakers to inform them of the new rules it is preparing. They entered into force at the beginning of this year.