turbo

i heard somewhere that installing a turbo help u get better gas milage dodes anyone know if this is true

No, any time you make more power you need more fuel to make that power.

i heard somewhere that installing a turbo help u get better gas milage dodes anyone know if this is true
This is not true of all modifications. Anything that improves airflow to/from (intake or exhaust) the engine will increase power while improving gas mileage. A turbo will decrease gas mileage on the other hand, but will vastly increase power and the gas mileage sacrafice will be minimal compared to supercharging.