I have to agree with this, I’ve had dozens of brand new cars and gas mileage usually begins improving at 15k and stops improving around 20k miles. This is what I consider to be “broken in”My 2025 Raptor has 15000 miles on it. And im just noticing in the last month that my mileage is improving. 19.6 mpg on the highway on last fillup. Might be truck might be me driving a little better now that the novelty has worn off a little.