Never heard of latio can go 20+km/litre. Even much better than the spec (which itself tend to overstate the FC as it uses ideal road condition measuring).
It really can be done... You just have to make sure that you select driving conditions that are more favourable than specified in the 10-15 mode test. Here's what I find works in my favour and for my totally stock condition Latio CVT hatchback (how can they call it Sport...???!?):
* Long trips (35+km per trip during work days) minimize warm up hits (since lots of fuel is being dumped during warm up to get the catalytic converters into operating range and warm up time is required for transmission fluid before torque converter lockup is permitted).
* A 70~75% HW ratio certainly helps.
* Slowing down on the expressway helps. If you drive at a constant 80km/h, you will easily get MUCH better FC than the guy doing 120km/h.
* Unlike most folks advocating more throttle for efficient acceleration, I tend to use a steady gentle throttle to accelerate. This encourages the CVT to select the highest possible gear ratio. You may not be able to tolerate such gentle acceleration.
* Avoid braking unecessarily. Keep ample buffer space in front so you can just lift your foot off the throttle if you need to slow down, instead of having to hit the brakes. Conservation of momentum is the key. Avoid accelerating towards red lights. Coast in N if you are far from the lights and you know it will still be red. Better still time it so it will turn green by the time you get there.
* Inflate your tyres and check their pressure regularly. Tan Chong mechanics like to drop your tyre pressures to 200kPa after servicing the car to give you a magic carpet ride with a more "solid" steering feel. I keep my pressures at 250kPa/230kPa for lower rolling resistance and lower steering effort (less juice required for electric power steering). The downside is a harsher ride and a tendency to have to pay more attention to your steering.
* Switch off the A/C and crack the windows open 2 inches if you are in town and it's early morning or night. If I really need the A/C, I keep it at 27~29C with fan at 1 (don't laugh, it works for me). Just enough not to break into a sweat.
* Switch off the engine when stuck at those terrible traffic junctions that stay red for minutes. When waiting to pick someone up, turn off the engine and wait outside the car.
* Keep your air filter clean (replace more often than Tan Chong does). You can get new ones from the Nissan stockists and change them easily.
* Don't use anything more viscous than 5W30 for engine oil.
