V8 with super/turbo charger fuel consumption?

[blo304]

Apparently cruisen on the highway you will see better fuel econ with a turbo/super charger..
around town would use more fuel then a stock car..

Only with supercharger not turbo. As boost is not being produced when driven at a constant speed like a centrifugal supercharger. While crusing the turbo is doing nothing. It is however creating slight backpressure which would normally not be part of the system and will cause slightly greater fuel consumption.