New and good quality tyres do not suffer the spontaneous air loss from the micro pores , as compared to average quality tyres. Xm2 mischelin are supposed to have less er and smaller micropore s , according to mischelin R&D. If proper pressure is maintained then pickup/ power loss will not be much as compared to others.
Also , nitrogen renders the car ligher, hence better pick up .
BTW ,our wagonr is suffering from continuous irritating rattle near or probably inside the lpg tank, which could not be rectified by BRC man, though he claimed that he rectified it. Similar feed back has come from my friend who owns a wagonr( BRC kit).