as u wish borther.but atleast let me explain.(we plugs do make difference but now much)
broter if u look at the basic working of an engine,its like air fuel mixture is being burned in the engine.the more mixture u put in,more power u get.to increase power,u install air intakes nd open the fuel supply to get more power.in ur case,u dnt hav air intake.nd u cant even put more fuel in as its efi.efi put the exact amount of fuel needed in the engine nd very little of it gets wasted,but in city,as it has 2 plugs per cylinder,not a drop of fuel is ever wasted.it has a complete combustion process.
performance plugs/wires help when ordinary plugs/wires nd not capable of burning the fuel to the last drop.so they increase the intensity of spark hence igniting all the fuel nd giving u more performance.if theres no extra fuel nd air put in cylinder,u cant increase power by these means.try other things,like air intake nd exhaust systems etc..
well its my advice but its upto u to decide.i knew all these things but still went for plugs,but the results were not encouraging.