25 isn't good? That's what my tiny sedan used to get and I sold it not even 5 years ago.
I'm having to convert to US gallons to Imperial here but...
My old ICE car was getting approx 50mpg (which is approx 41mpg for you) and was considered poor for its age. My new one (hybrid) is 60mpg (approx 50mpg for you).
For a fairly modern car (e.g under 10 years old) in the UK you'd expect at least 40–50 MPG (UK) / 33–42 MPG (US), and even that would be considered on the lower end. Most modern cars are either electric or hybrid here these days so you'd expect 60–100 MPG (UK) / 50–83 MPG (US).
The Toyota Corolla (second best selling) is then lower again.
US cultural perceptions on fuel efficiency are bonkers.
I can easily belive it, though the closest Civic mpg report I found was for a 2012-14 model:
What is the fuel economy, Honda Civic IX Hatchback 2.2 i-DTEC (150 Hp)?
4.4 l/100 km
53.46 US mpg
64.2 UK mpg
22.73 km/l
I had use of a Renault Megane for a bit, it was getting something a bit better than that: https://www.auto-data.net/en/renault-megane-iii-phase-ii-201...
American cars just aren't at all efficient by anyone else's standards.