Try ZAP mode I think ZAP mode is giving more milage compared to ZIP. I always do brim level and recently I purchased Z8 L DSL AT and got 13.21 in city. Yours is manual it may give around 20 if driven nicely.
Brother I want to ask 1 thing is there is any problem in the clutch .....means that in shifting or there is any hardness....in putting the gears....please reply sooon sir because my new vehicle is coming in 2 days