A319's do not have a central tank
Sorry gilesdavies but not the case. Easy's A319's are weight limited for navigation/airways charging and seasonality. Max Takeoff weight for the A319's are 68,000 kgs and for the A320's are 77,000 kgs. Fuel tanks are the same on both variants.
red5, the only cabin differences are an extra loo down the back and the extra seats. Same poxy oven in the front on both the 319's and 320's