[john70t]

(The Autozone website returned an 'access denied'. Must be doing something right. brrr-bzeet-bop-brrr.)


https://cartreatments.com/copper-vs-iridium-vs-platinum-vs-double-platinum-spark-plugs/
Iridium:
"One of the reasons iridium spark plugs last so long is their small, yet dense, center electrode. This design requires less voltage to generate the electric current needed for combustion, making them a popular choice among car manufacturers.
(Is the firing voltage the same? ie coil wear)"

Platinum:
"But durability isn’t the only benefit of platinum spark plugs. They also generate more heat, which helps to reduce deposit buildup and help prevent fouling. That means less maintenance and more time on the road for you."

Double Platinum....um....
Wait a second.
Um. What?
When does a spark plug control the ignition system?
"If you’re driving a car with a waste spark system for its distributor ignition, double platinum spark plugs are often a good bet. This system fires the spark plugs twice, once in the compression stroke and once in the exhaust stroke. "