1) Take weight out of the car. Front seats are very heavy. A/C & power steer. Spare tyre, jack, parcel tray, etc. There's been other disscussions about this
2) Run biscuit tyres with overinflated pressure. Lower rolling resistance. Should be lighter too.
3) Remove power steering.
Aside from the weight, from memory it adds about 2% to fuel consumption.
4) A manual gearbox should give you better economy than the CVT & it's lighter. While current model CVT's might come close to equalling the economy of a manual box, or in some cases bettering it, this is partly achieved because of an electronic throttle, which the K11 doesn't have. Newer CVT's also have a wider gear range.
5) Better inlet filter & cleaner flowing exhaust system.
6) Better computer & O2 sensor, running the motor leaner.