I bought these to replace the factory spark plugs on my 2005 Camry 2.4L I4. I'm at around 58K miles but the original plugs are about to hit 11 years old. For the price, I decided to just replace them. I wasn't seeing any particular problems except for a slight vibration at idle w/ the AC on but I consider that completely normal. I didn't want to leave the originals in for 15+ years and not be able to get them out, despite Toyota saying they are good for 100K miles.Steps for the Toyota 2.4L:- Remove plastic cover from top of engine (if equipped)- Remove coil pack boots- Remove old spark plugs (mine were NGK)- Install new plugs- Put coil pack boots back on- Put plastic cover back onThis was my first time replacing spark plugs and it was very easy! As my car gets older I am learning how to do things on it, like brakes and whatever else. I changed my PCV + PCV hose along with my spark plugs and the car feels better. Gas mileage is the same, pretty crappy in the city but I drive "spiritedly" - idle is smooth, engine runs quietly.I opted NOT to put anti-seize, I read online that there's some kind of coating on the plugs already and that both Denso and NGK advise against anti-seize as well. It has to do with it changing the torque values. If these plugs last another ten years, I will probably get rid of the car before I ever have to change it again anyway.Overall, very happy. I think the price is fair for iridium tipped plugs that will last 100K miles. My factory plugs still looked very good after 58K miles / 11 years so I have no doubt that these will last a while as well.