Spark plug NGK or OEM Mazda

Change spark plug to ngk iridium.

they certainly look to be different heat ranges. do yourself a favor and stop going to the dealer for spark plugs. the only different between the dealer spark plug and a big box store spark plug is that one does not come with the VW logo stamped on the side of it. they are otherwise the exact same plug. just go get yourself some new NGK's (all 4) and put yourself at ease.

I used NGK plugs in mine. A bit expensive, but they work great and I get 6 litres/100km for fuel mileage.

NGK (Mazda OEM) or Denso are my picks. Personally I think both brands are as good as each other. I buy whichever is cheaper that suits my car.

NGK laser iridiums are the ones I just put in. You don't have to do it often so the price tag doesn't hurt as much I guess is one way of looking at it. Also buying good plugs will help you NOT spend a ton more money further down the road on repairs.

In all the cars, boat motors, and regular lawn equipment I change plugs in… NGK is the best there is.

Ignition system overhaul (spark plugs, wires ignition coils), a new starter like the one on amazon is a nice bandaid.

I just tossed some oem NGKs for the first time since... 30k miles, and they seem to be the best plugs I've ran, although they are not a step colder as recommended.

I changed my own with about 50 US in tools. Its a pain to do without dropping the motor down which i didn't do.It took me about 3 hrs for 4 plugs. Replaced with nkg plugs at about 25 each. I have the tools and know how but I'd probably pay someone 500 dollars to not do it again. It was an eye opening experience.

Replacing a motor is not fun, nor cheap. That was with 9006 RS7's btw (your current plugs).