2007 Honda Civic Hybrid here.
I used to drive 80+ in the country and anywhere from 60-70 in the more urban highways. Punching acceleration, braking hard, etc. Only got about 32-34 in those conditions.
I've started doing 55 in the urban highways and 70-75 in rural. Slower acceleration, etc. I am only getting 36 over the last 1000 miles due to winter driving (snow, cold, startup times, etc.). March through September I averaged around 46 with my top mpg on one tank at 52. So, I'd say 45 is attainable in normal conditions, but you should expect lower 40s if you don't drive like a maniac.