I use 80+ NGK's yearly...so far so good

I like and use the Auto lite non resistor race plugs now as well as their resistor plugs in my street vehicles on gasoline and E85

I have been using the autolites as well. 3911 and 3923. Although i think the 3923 is too hot for street and the 3911 may be too cold for track use in my 511. Hard to find a projected non resistor in a 7 range.

All I use now is NGK plugs, never had a problem with one. I used to use Champions but had problems with the newer stuff.

These were atv plugs...

For my cars I use Autolite AR3933 series AR3935 or AR3932 or AR3934 depending on needed heat range. Best plugs I have ever used.

Some of the larger chain parts stores buy plugs from some jobbers that sell the counterfeit junk

NGK and Denso user for 38 years without failure.

Gus

I like the autolite stuff as well as NGK. I dont know if its worth anything, but i like the cut back ground strap autolite offers.

NGK only for me for the past 20+ years. No issues ever.
Nothing against other brands really, just more familiar w/ the NGK numbers.

NGK as well.

I prefer NGK vs champion plugs What are your other options?

That is the last thing we need. Real businesses buying conterfeit parts and selling them to us.
It is bad enough that illegal crap manf exist in the first place.
Just trying to change spark plugs turns into a nightmare....

It would be nice if somebody knows how to spot them, if possible.

I called NGK and gave the numbers on the plugs. He told me wgat plant and when made amd if real.
Also said they do not copy-fake copper or nickel one's. But plenty of fake iridium ones.
To buy from a real place. That Summit Racing is authorized source, and Rockauto gers them from one and is also safe.
I like how the coating NGK puts is easy to read.
Ford spects NGK so does Honda. The Honda small engine stuff i have us Ho da boxes with NGK
If i can't get NGK it is Autolite

Just an FYI... NGK is likely going to buy-out DENSO for spark plug future production... according to certain business news. DENSO forsees the future of internal combustion engines declining.. so their potential exit from that market.

I see a potential need for diesel tow trucks with an EV generator onboard...

Honda eu3000i: Would run for exactly 90 seconds, then die. Cleaned complete fuel system. Ignition always had spark. Fortunately, good friend has same generator. We swapped EVERYTHING. Still, run 90 seconds then die. I decided to change the perfect looking oem plug. Wala. Problem solved. It had to be at the exact temperature to short. NGK.

Been running NGK in the race car for many years. Never an issue

Only NGK for me in all the racecars for the last 20+ years.

NGK is the factory plug for all the Japanese motorcycle manufacturers. Never saw an issue such as the OP posted over decades of experience with them.

I saw a "reel" on Instagram that showed how to unscrew and replace the tip on the ignition wire end with a solid core tip. They said their example is specifically for a Mopar. The replacement tips can be re-used again and again in fresh plugs. Not sure where they get them, but figured some of you guys know.

I guess I am not the only one that caught some bad ones this year:

https://www.youtube.com/watch?v=_GY7feZi_IQ