I use my 09 Fit as a courier vehicle. I've driven over 80,000 miles in 14 months. If I did oil changes every 5k miles, I'd be under the car every 3 weeks.
I just follow the maintenance minder, which works out to 10k miles, give or take, but I've done that over all the 175,000 miles I've put on it in 10 years. I use Castrol GTX high mileage, but I'm sure it doesn't make much difference. I've seen a lot of stuff saying Walmart Supertech is probably just as good,if not better than name brand oils.
I do my own valve adjustments, and the inside of the engine is nice and clean...