They arent too bad. I just removed mine for a 200tdi conversion but the petrol wasnt that bad. Mines a 110, sat at 60mph on road quite happily, plenty of torque offroad.
Approx 20 to the galon in the 110 with nearly 100k on the clock. Funnily enough I just stripped the 2.5 petrol engine today and im about to stick a load of bits on ebay! If you need anything, you know where I am.... :D