My 2014 Toyota Prius uses iridium-tipped spark plugs such as the Denso SK16R11 or the NGK IFR5A11, both usually set you back around $20, but if you buy them from the official toyota dealer, they will set you back $150 ! but I have no choice, as the market is flooded with counterfeit spark plugs, and changing the spark plugs on the prius requiers the removal of the wiper area !
What about those $150 spark plugs (I will check the exact price and update this soon, so when I took them out after less than 5000 KMs and found two of them broken ! specifically the Insulator Nose (shield) around the copper core !
I had a failing head gasket, and the removal was part of fixing that, so I thought that the seeping oil or water into the piston might have been the problem, but since i maintained their order after removing them, It turns out that the one that has the inner shield fully broken was in a piston that did not suffer any head gasket leak !
