well, city driving uses far more fuel, especially if you like to accellerate harder than most Volvo drivers. This is because it takes more energy to change the velocity (speed) of an object, than it does to maintain velocity.
In other words it costs more to speed up or slow down than it does to maintain speed, which is typical of highways.
I noticed mine was 11.5 and dropping, city yesterday morning, because I was feeling good and life was pleasant and I felt like being calm.
Yesterday avo, however, I had the shits with work, slow drivers and traffic so booting it caused me to go to 14.something rather quickly, which made me more pissed off, which made me boot it more which used more fuel which I had to stop harder because of the slow drivers and the traffic but the fuel was going up so I booted it more....:ranting:
deep breath.......