[Irish]

Originally Posted by kz1000st

Over the decades I have tried them all. Gold Palladium, Iridium, Platinum, Copper Core, regular materials. British, German, Japanese, Chinese. Here's what I'll tell you. There has been no difference in power, fuel mileage, cold or hot starting, throttle response. I had a Chinese Torch plug in the 150 that I changed to an NGK Iridium-no difference.

The only thing I ever noticed is that the more expensive plugs lasted longer. Here's my favorite anecdote. A few years ago I had my Plymouth minivan in for service and I decided to have them do plugs and wires. The Plymouth calls for a plug gap of .050 inch. I saw the standard Mopar plugs they pulled out. They were easily at .100, maybe more. I have no doubt they were the originals or second set and this car had 175,000 miles. It only ran slightly better and gave me 2 more mpg on a trip.

Today's ignition systems are so good in comparison to points and condensers of old. Spark is much higher voltage over a microscopic amount of time. Spark plugs are a very small part of the equation.

If I get everything correctly , it's not worth changing to Iridium Plugs!
Is that correct! Irish