Spaceboy wrote:
i had a weber on my sillycar, when it opened the 2nd jet it gave a real kick to the power! but even on a single jet it ran too rich and wasted all my fuel down the exhaust pipe

That's cause it wasn't setup properly.
Anton, Other than the fact that it is noisier, produces more power hence more fuel used (More fuel + more air = more power) there's nothing to complain about. I think the difference in fuel usage compared to twin SU will be minimal (like 1-2L more per 100km).
I think the perception that they use more fuel comes from that fact that when you do have a weber you are much more tempted to fang her so you will use up more fuel due to that alone than anything else! If you baby her around she will give you average milleage if it is jetted properly. It's logical, air fuel mixture should stay around 12 lamda so I can't see why a car with twin SUs will use up more fuel at 12 Lambda than a weber at 12 lambda. Make sense?? The only differing factor is 1) the throttle pump which you can get past by not constantly stomping on the pedal and 2) Revs.
On another note, the difference in everyday driving will be that you can't directly stomp on the pedal full trottle from low RPM. this will result in a puff of black smoke and nothing much else...