Resistorless spark plugs
So it looks like there are spark plugs with built in resistors and spark plugs without
What did our cars come with ? The dizzy cap engines ? Coil on plugs ? Is there some way to tell this from realoem.com etc ?
Can we pretty say that any engine built before a certain year would not have had such resistor plugs ? If so, any idea on that date ?
Do resistor-less plugs burn hotter ? Even if they do, would it make any noticeable difference, either by butt dyno or by fuel economy ? Thanks..