Jean-Paul, Yea a Snow day, 36" and more falling.
Try looking at the shoptalk fi forum. Many have played around with these systems.
The CB Performance system I have been using is not set up for fuel effientcy. The best mpg I achieved (before turbo) was 24 combined town/highway driving.I have the Ultra Comp which is an open loop as opposed to the closed loop. The difference being the closed loop uses more sensors to monitor the engines status and makes adjustments accordingly, hopefully improving how well things work. The open loop is simplified and not really street friendly but it does supply gas for power.
If I were to start over with this direction I would use CB's hardware but get the ecu & sensors from another source. John Connoly's outfit carries a self programing ecu that looks perty good, the one already mentioned is also spoken of frequently on the shoptalk threads. The fi from vw are made specifically for those engines. Adapting them for a beefed T1 probably can be done but not a straight forward install.