After a $2,000 price drop on Wednesday, Tesla buyers just got four more reasons to choose a Model 3 Mid Range.

According to the order page on Tesla's website, the Mid Range Model 3's EPA range rating went up four miles overnight, from 260 miles to 264.

To be sure, it's a minimal improvement on top of what was already a pretty useful number of miles—about a percent and a half.

READ MORE: Lower-cost Tesla Model 3: Does 260 miles, $46K before incentives split the difference? [Updated]

We reached out to Tesla to ask about how they made the improvement, and the company responded with a statement, saying: “We have updated the rated range of our Model 3 Mid Range to 264 miles to more accurately reflect the results that were achieved during testing.”

It's not clear whether company engineers found a little more efficiency in the battery pack or the motor controllers, if the car gained efficiency by some other means, such as different tires, for example, or if Tesla or the EPA simply performed new tests and got better results.

Though Tesla has not released official specs, for the Mid Range battery capacity, it is estimated to be between 60 and 62 kilowatt-hours. 

DON'T MISS: Tesla Model 3 Mid Range goes an EPA-official 260 miles

Last month, the EPA released official efficiency estimates for the Mid Range Model 3 of 128 MPGe in the city, 117 highway, and 123 combined, slightly lower than the discontinued rear-wheel-drive Long Range Model 3. (The Long Range version is now only available with all-wheel drive.)

While automakers conduct their own tests according to EPA specifications, the EPA regularly conducts cross-checks with its own tests.

If we had to speculate about what improved the Model 3's official range, we'd guess that an EPA follow-up test delivered better results than Tesla's own tests.