Air have 70+% nitrogen content, it does not hurt if you'll mix air with nitrogen inside your tire. Of course, you'll be contaminating the nitrogen in your tire, better load nitrogen nalang pangpuno kung mo decide ka ug nitrogen gyud imong ibutang sa ligid.
Wala na ko mi pa karga ug nitrogen puro sa ligid, kapoyan ko pa karga ug nitrogen whenever kinahanglan pun-an, I only use ordinary air nalang but I use tireseal (
Tire Seal Protection System - Anti Flat Tire) hoping it will lessen air leaks and it did work well keeping the tire pressure up for a longer time than without the tireseal. Ang primary purpose sa tireseal kay pag pugong nga mo leak ang hangin kung matunok ang ligid but my purpose of using it is to minimize refilling of air, extra feature nalang na para nako ang no more flat tire kung simbako matunok ang ligid. hehe