My fuel consumption has changed since I moved work to city.
I travel around 15km to the Brisbane CBD area and it's pretty much bumper-to-bumper traffic all the way. I'm averaging around 9.2L/100km
It's gone up about 1L-1.5L compared to before when my work wasn't in CBD.
I think it's still excellent considering it's stop and go traffic 90% of the time.