Spark plug NGK or OEM Mazda

Thought I would follow up on this discussion. Ordered the NGK LFER7BHX Ruthenium HX. The priority package showed up after some challenges with the local Postal Service. As advised, on Tuesday took the car for a short drive to warm it up then started the task. Was a little pensive taking the engine cover off. To anyone who has never done it on that particular car, just pull each corner straight up about an inch and it comes right off. The cover is held on with posts that fit into rubber grommets so the chance of breaking anything is almost zero. Found a very old 10-14mm open end from the tool kit from a long gone motorcycle in the junk drawer, A few minutes with the belt grinder and a "perfect width for the ground bolt" 10mm open end was discovered hidden inside. The only real challenge is disconnecting the wiring loom from the coil packs. Several iterations of 'watch a video, give it a try, watch a different video, give it a try ...' ensued but I was finally able to get them disconnected. Gently removed the coil packs and one-by-one removed the plug, installed a new one, torque to 30Nm, wash-rinse-repeat. Put a little dielectric grease into the plug boot of the coil pack and the coil pack\\wiring loom connector, a little SYL-Glyde Silicone Grease on the large coil pack to engine seal and reinstalled the coil packs. Torqued the ground bolts to 12Nm, then put on the ground strap and torqued the nut to 12Nm while holding the bolt steady with the afore mentioned "super wrench". Fought with the wiring loom to get it back on all the coil packs, popped the engine cover back on and Bob's you uncle. Drive to the dealer Wednesday morning and went in to talk to the Service Writer. Mentioned that they did not have to rotate the tires (had already put the X-Ice tires on two weeks earlier) nor change the plugs as I had done that the day before. He gave me a strange look and said "Yes, VW recommends they be changed but with only 15,000 miles on the car I would not have bothered". Doh!!! Primary lesson learned here is "Call and schedule service yourself rather than let your wife do it." That way you can challenge the items on the "what will you be doing at this service" before spending an afternoon under the hood. (Side note, it is 'her' car as 'my' car is the FRS, hence her desire to schedule the maintenance.) They did the usual "full inspection" on the car and came back with "the rear brake pads are down to 3mm and should be replaced". They had photos to "prove" the pads were down to 3mm. I though this was strange and will be starting another thread to go over that discussion with the Service Writer.

I use NGK Iridium. They seem to burn a little cleaner than some other plugs I’ve used in the past.

I've decided to install the plugs myself. Given that the vehicle has nothing in the way of a tune, it would seem that the 'standard' heat range plug would be the best fit. APR does not seem to offer a 'standard' heat range plug so they are off the table. The prices for the NGK plugs from the dealer seem reasonable even there challenge is 'which one?' They list a 06K905601B Type 1 and a 06K905601L Type 2. Google searches offer nothing in the way of information about the difference. Is it the heat range? the external construction? the internal construction? the ???. There is a price difference in that the Type 2 is over twice the price of the Type 1 so I am assuming there is some difference, but no specifications to suggest what. To ensure theMuffinMan understands what I am saying ... I am not sensitive to the price difference BUT it is the only factual piece of information I've been able to find, other that part number, to distinguish one from the other. I am stating the difference as a fact and not as part of the selection criteria. Looking at the NGK offerings, they seem to be NGK PLFER7A8EG Laser Platinum or NGK LFER7BHX Ruthenium HX. Any insight would be appreciated.

NGK (who makes the VW ones) offers upgraded Ruthenium HX ones for less money (NGK-supplied VW ones), with improved performance and longevity compared to their aftermarket Iridium-IX ones.

Currently using the NGK racing R7438-8 (NGK 4905)

Ruthenium HX 95125. Lots of good feedback on the forums, I’m using them out of the box gap and they’ve been great. About 5K miles so far

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.

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

That’s curious….. if you look closely at the end of the shorter plug you can see another set of threads, it looks like there an insert threaded onto that spark plug. It would appear that it wouldn’t be sitting where it needs to in the combustion chamber so that may explain your misfire.

Recently i changed my spark plugs DENSO IRIDIUM IK22 with NGK BKR7E gapped at 0.28inch-0,70mm. The car became very laggy, the throttle response got worse, much more turbo lag and major lost of power. Also im going back with the Densos.