darsh

Spark plugs come in three types: Standard, Platinum and Iridium. Standard is the one that always goes in Mazda 3 and you can upgrade to any one below as you like and afford.

Standard: 10-15 dhs/pc = 15,000-20,000 kms life.

Platinum: 30 dhs/pc = 40,000-50,000 kms life.

Iridium: 45 dhs/pc = 80,000-100,000 kms life.

However fuel saving is not that much as your friend advise it might save 5-10% from platinum to iridium but power gain and smoothness will be noticeable added with extra life.

they were more then 500 my friend.

how much will it cost me if i change the brake rotors? i have got a quote from two or three good workshops and its very expensive for me.