Owner reviews for spark plug

APR Iridium Pro Spark Plugs are the excellent upgrade for tuned engines. Our spark plugs are made from Iridium, which is one of the strongest materials you can use in this type of application. They run cooler, resist preignition, last longer than other materials with higher melting points, and even require less voltage to produce a strong spark. The electrode is harder and stronger than other materials, can dissipate heat more easily, is better protected from melting, cracking, and other limitations found with standard plugs. These plugs were designed for use on tuned and higher output vehicles that benefit from a plug cooler than the factory heat range. They are great for high boost, high cylinder pressure, high cylinder temperatures, and high power situations, and they pair nicely with a set of APR ignition coils, where applicable.

From literally every single objective comparison, the NGK ILKR9Q7G looks like be identical to the HKS M45XL except for price. NGK literally produces the plugs for HKS and NGK is likely the largest plug manufacture in the world with decades of reliable products to boot.

if not oem ACDelco get ones from the likes of ngk, or bosch.

Mine are either ACDelco or NGK, cant remember which. Either way no complaints.

New Denso wires (these were the OEMs, cheaper to not pay ac delco mark up) and AC-Delco 41-962 plugs.

AC Delco/NGK.

IMHO, this is one of the times where the OEM stuff might be the best way to go, especially if your engine is otherwise stock. It's really common to see these trucks get well over 150,000 out of the original plugs and wires. They're kind of expensive but they just last so long it's worth it.

Denso IKh024

New NGK plugs were a definite improvement. MSD coils were not!

Once we got a good local supplier for Motorcraft plugs a few years ago we almost never install Autolite.

There seems to have been quality issues with those for quite a while. I couldn't count how many times we removed fairly new Autolite spark plugs and replaced them with a better brand to fix a misfire.