I have been through one of these fleet driver managment thing's using the boxes.
Some have a gps others don't, they have a accelerometer and also sometimes a 3G sim card to send the data.
The lorry fleet was about 50 units and the boxes were installed, bitched about then ignored. After a month a bloke turned up with a laptop and plugged it into your engine managment system. Then let you drive for a bit. Then he drove for a bit. You then had a look at fuel burns through a range of gears etc etc. Then he got you to drive in his style and you had another look at the laptop. The up side was that all the new units that came in were the highest powered beasts on the market. Something to do with smaller engines having to have the turbo kicked in all the time where as the larger engine could sit with it out most of the time. The extra 20k for the larger engine was covered in 4 months of operating.
Result was after 2 months the fuel bill was decreased by 15% and 3 people arrested for stealing fuel.
Whats the fuel bill for the three services?