Right recently i have moved to a house in the middle of nowhere as its closer to my work. im just renting a room. i left for work one morning and it took half a tank of diesel to go 20 miles! found out that one return fuel pipes on top of the intectors had split (so i thought). got it replaced while at work and noticed more damage to insulation. going on a hunch i suspected mice were getting in my engine bay and eating things including fuel pipes. the next night i found more damage on the new pipe and that basically confirmed my suspicions. so now i set mouse traps in the engine bay every night and have ended 3 of em so far. but yesterday i started to smell diesel again popped the bonnet up and sure enough there was a well of diesel sitting in with the injectors. no damage to any of the pipes. i have recently had 2 injectors refurbished and on one of the a helicoil had to be fitted cause the tread got stripped. so today i have re-torqued the clamps and that seems to have stopped fuel coming out again. filled the tank up and now im getting and instant mpg of around 20! i dont know if the ecu is catching up on the lost fuel from before or if i have fuel pipes under the car getting destroyed by mice.