spark plugs

[ierave]

2 of my 4 spark plugs need to be changed on urgent basis but the other 2 are good to go for next minimum 6 mths ( the previous owner only got 2 spark plugs changed)

now do i change all 4 of them or the urgent 2

these are a higher grade of spark plugs and i am confused what should i do

[abdullad]

Change all 4 for best performance and saving hassle and labor cost to change other 2 after few months.