4 ms·

Consumer Reports did a study on this and it only reduced gas mileage by 3% on a Honda. https://shop.advanceautoparts.com/r/advice/car-maintenance/common-ac-and

• boomboomsubban 2y ago
  At 65mph and ~85 degrees. The page I linked sources several studies testing at many other temperatures and speeds.
  • chrisco255 2y ago
    No car takes a 25% hit from the A/C in gas mileage.
    • boomboomsubban 2y ago
      >The internal combustion engine (ICE) variant has an estimated fuel efficiency of 14.7 mpg‑US (16.0 L/100 km), decreasing to 8.6 mpg‑US (27 L/100 km) when the air conditioning is on.