Once you've driven the car for awhile you learn when the best shift points are for speed and for fuel economy. I typically drive about 50km (return) in peak hour traffic to and from work taking anywhere from 30 to 45 minutes per trip and I can average around 10l/100km (I get around 600km out of a tank when I refuel after the light comes on). Alot of it is learning to read the traffic and knowing when to coast, as well as knowing how much throttle to apply. If I wasn't doing peak hour traffic everyday I'd say I'd be closer to 9, but I have a fairly sedate driving style these days. My favourite game is the "how far can I get on a tank" game. You won't match the fuel economy of a light weight FWD coupe however.
Reliability is going to be partially 1) how well the previous owner took care of the car and 2) how well you'll take care of the car. If you take care of it, the MPS shouldn't develop any major issues it hasn't already after 50000km.
Check your rear diff mount.