Driving impression: JCB Fastrac 3230 Xtra The addition of the Xtra decal to the 3000-series Fastrac livery signifies much more than a modest cab tart-up. Look under the skin and you’ll find the firm’s P-Tronic semi-powershift transmission. And on top of that the Cummins motor is now able to provide some useful extra boost muscle when working in the tractor’s two highest gears. Mervyn Bailey gets behind the wheel