GreenHybrid.Com has a database of real-world mileage reports from hybrid car drivers. It now has statistics from over 1000 different cars in the database. The site also has an active discussion forum and a learning section where you can read about the basics of hybrid car technology.
Real-World Hybrid Mileage Reports
October 12, 2005 by 1 Comment
I have some real world MPG figures for cars on my website
http://www.WhatMPG.co.uk
It also shows manufacturers figures for used and new cars.