Improved fuel economy

I'm not 100% sure what has caused it but my last 2 tanks of city commuting only, the last bar starts to flash at about 210-215 km instead of 180-190 km

At about the time the improvement happened 2 things changed:

- a new battery

- a section of expressway opened up on my route to work, 3.5km and I avoid 4 sets of traffic lights and a train crossing, moderate traffic on the way to work, on the way home it used to be quite congested

I wouldn't have thought the expressway alone would make that big a difference, and I wouldn't have thought a new battery could make any difference whatsoever?

it's the steady state throttle compared to going up and down the gears 
can make a big difference