The basic idea, is that when the car are off-throttle, the front wheels freewheel. This way grip aint used for acceleration/braking, but all the grip are avaible for steering. Result: Faster cornerspeed.
The downside is, tha car can only brake with the rear wheels. Big risk of spinng out, if one touches the brake. Therefor they are best suited for high grip tracks.
So they aint for beginners. And usually they require quite a lot of traction. However, at this point, it aint unusual to gain 1-2 more laps pr. 5 minutes race.
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250