Fuel consumption

I'd suggest there is a fault somewhere. Is it running ok generally?

My 2001 Renault Laguna (1.6 petrol) used to average about 35mpg in stop/start traffic, dropping to about 25mpg if it was really horrendous (coming back from the wrong side of the Pennines at rush hour on the M62 for example). Even dear old Gothilda does more than 14mpg in town work (she does about 20mpg in town, 24mpg on my current commute which is mostly 60mph but with a lot of slowing down for tractors and wagons), or about 30mpg on a clear run on a motorway or dual carriageway.

My Laguna's mpg dropped like a stone when it developed a fault which didn't present symptoms in town work for ages because she didn't need much power. One of the ignition coild failed, so it was only firing on three cylinders, but of course the computer was still sending fuel to all four. This only became apparent when you got chance to floor it and it didn't accelerate too hard, and only started to run noticeably lumpy when a second ignition coil started to fail intermittently, so it was sometimes only running on two cylinders.