Dude, I've been running Bosch Platinum for 2 years and they work great. My mileage wasn't effected by the change and I have no 'engine damage' from them. It's just like the stupid antifreeze argument. It doesn't make a difference in my opinion. I've ran green coolant and Bosch plugs with ZERO problems. Stores wouldn't sell you Bosch Platinum plugs if it caused engines to fail all the time. Use some common sense.
Here we go...
First thing you need to do here is realize that you can be held liable for bad advice you give on a web forum. If someone follows your advice and has that engine damage they can come after you. Which is why I am very careful to stick with OEM recommendations, especially when there's no reason to do otherwise. Chrysler specifically warns against engine damage on the 4.7HO using other plugs. They don't do that for any other engine or any other aftermarket part. Seems silly not to follow their advice.
In this case, it costs the same to do the job right or to do the job wrong. Buy the right plugs for $3 or the Bosch plugs for $3. Why not buy the right ones? Same for Antifreeze. Does the extra $2/gallon (every 5 years!) break the bank? And yes, it DOES matter because the green antifreeze contains silicates that your water pump will not agree with. The aluminum heads, water pump, timing cover, and radiator will slowly be etched by the green antifreeze because it does not have the corrosion resistant properties of the HOAT coolant that is required.
Again, why use the wrong product when the right product is the same price? I'm not saying that Chrysler is the all-seeing all-knowing auto manufacturer, but I trust the service manual a lot more than I trust you.
"Stores wouldn't sell you Bosch Platinum plugs if it caused engines to fail all the time." - Stores actually sell all kinds of detrimental products. It's up to the buyer to be informed enough to know what to buy. Remember ZMax? Huge class action lawsuit. Slick50 engine treatments? Treatments with Teflon? Teflon is a SOLID that does not belong suspended in your motor oil. The larger pieces get filtered out by the oil filter and the smaller ones just circulate, eroding the soft metal bearings.
Lastly, like an idiot I have used Bosch plugs over and over and over because I wanted to believe that they were good - Bosch makes good products in general. My experience with their plugs has been negative on every single vehicle I have used them on. Misfire codes, dropping mpg, rough running. In every case I have gone back to OEM plugs and solved the problem. On my last BMW, I tried the Bosch platinums to save $6/plug and found that they wouldn't hold torque in the heads. The crush washers were WAY too soft and with thermal expansion they would work themselves loose in 500 miles or less. Retorque. Self-loosen. Retorque. Finally quit and bought the OEM NGK plugs and BOOM, problem solved forever.
*Exception* There was one
car I owned that specced OEM Bosch tri-electrode copper plugs and that was the ONE car that ran great on Bosch - because they were OEM, and NOT platinum.
I'll stand behind my words and experiences and recommend only the OEM plugs.