Hi Everyone. Can i ask Whether the 4g15 and 4g13 engine is basically share almost the same thing except for the engine block? Recently Im driving a wira 1.3 aeroback and i found that it is lack of pickup and high fuel consumption. Since the price of 4g15 engine in market is so high, So thinking of just changing the block and parts from a 4g15 if possible. Thank you if anyone could help?