Hi all,
Just charted my 100th tankfull of gasoline on my '04 HCH MT.
Here's my stats and observations:
I'm currently at 57,000 miles. Bought new in April '04.
Still on original tires and brakes - only oil&filter changes (0W20) every 5,000 miles. Air and cabin filters every 25,000. I do ALL my own maintenance. My local dealer sucks. I don't think I'll do the "Product Update", unless it bears out on this board it's worth it.
Average (indicated) MPG = 48.0
Average actual MPG = 47.5
Best tankfull (actual) = 54.2
My average cruising speed is 73mph, 80% highway, 20% heavy traffic.
I do try to keep a steady speed(cruise control is the way to go!), but will pass idiots and semis whenever they're less than 65mph. (I'm NOT one of those 55mph, far right-lane driving, maximizing mpg drivers!! I believe they are a traffic hazard.)
I drive ~200 miles per day. I try to drive my motorcycles every other day(even thought they get LESS mpg!!)
The car has been mostly flawless mechanically. I have hit a deer - $2700 damage. I got rear-ended by a semi, which was surprisingly only $800 damage - gotta' love plastic bumpers!
I've done several cross-country trips with 4 persons in the car and luggage, with no problems. The battery does fully deplete in the mountains.
My battery guage usually reads over 3/4 full while cruising the highway.
I have put over 13 gallons in the fuel tank on several occasions.
The MPG takes a serious hit in the Winter - worst tank 39.2 MPG January when it's ~10F in N. Illinois. The car likes the HEAT for better mileage. The car doesn't like rain or snow driving.

'Bout it. Any questions?

I like my Civic Hybrid!