I was thinking about the vehicle database the other day while driving. If people are given the option to either manually calculate their mileage and input it into the database or just go off of what the vehicles trip computer spits out how does the database keep the stats accurate. As others have posted and I have found out for myself the vehicle trip computers are off by about 3mpg which would skew the database if this were unaccounted for. Is this accounted for within the system and if so how?