NGK 90083 LTR5BI-13 Laser Iridium Spark Plug, Pack of 4

Seem authentic and at a good price. NGK is a trusted high-quality OEM brand. There are cheaper spark plugs available, but if a cheap plug breaks in your engine, you'll regret losing $1000s by trying to save $10s. These are rated by NGK to last 100K miles and I expect they will, (but of course I'll inspect them at 60 and 80k)

OEM equipment just not in the Porsche box for less than 1/2 the price

NGK Spark Plugs are more expensive, but I've never gone wrong with them. Be sure to gather the necessary equipment, extension bars, etc. before attempting to change your spark plugs, and it should go smoothly. For these in particular for my 2010 Mazda3, I needed a 3/8 6" ext. bar, 8 mm deep socket, ratchet, 5/8" spark plug socket, and 15 mm spanner. The biggest thing is to make sure you are turning in the correct directions, and if you've never changed your spark plugs, you may need to turn counter-clockwise with some force to loosen the spark plug. I also had a pair of needle-nose pliers to pull up my spark plug socket as it may get attached to the spark plug when you are trying to take the socket out after the new spark plug is in.All in all, spark plugs delivered looked good, and my car sounds great.

Having trouble finding the plugs referenced in your owners manual for a 2010Mazda6 2.5 4 cylinder? That number in the owners manual is discontinued......these are the NGK recommended plug--highly recommend you verify your application by looking up on the NGK website like I did. These do not have the little "crush washer" that are on most plugs--these plugs are a tapered seat fit--no torque settings on the box, the box says to tighten 1/8 turn (I think that is what it was 1/8 turn or 1/4 turn--you should read the box yourself to verify.....). I generally would use torque wrench, but not this time--did what the NGK box says rather than torque specs others might say on forums. So far all is fine 2,000 miles later.

The old spark plugs ran for 95K miles w/o any issue, but the mileage seemed a little drop. No issue with the new ones so far, will update after hundreds miles.

These work great in a 2011 Mazda 6 with the 2.5L engine. The previous owner never changed the plugs, which had now accumulated 124,000 miles. The old plugs were a pain to remove but surprisingly in very good condition and not causing any driveability issues. I have no doubt this new set will last 100,000+ miles (although I plan to change them well before that to avoid repeating the difficult removal process). The price was shocking but why mess with cheaper parts when the car runs so good on these.In case anyone is confused by the ILTR5A-13G plug number referenced in the Mazda owners manual...NGK 3811 (ILTR5A-13G) was discontinued - Replaced by NGK 90607 (ILTR5K13) for Ford/Lincoln/Mercury applications and NGK 90083 (LTR5BI-13) for Mazda applications.

Used these for our 2011 Mazda 3 hatchback a few months ago, so far so good. Didn’t notice any change in smoothness or fuel economy, but it’s not worse either.

Installed these last month on my 2010 Mazda3 Touring (2.0). They seem similar to the stock iridium plugs which lasted 90,000 miles and they perform perfectly. I've always gotten about 28-30 mpg during mixed driving depending on traffic and use of air conditioning and these seem to be as good or maybe a little better than the original. Installation was super easy (see YouTube videos) - just be careful not to cross-thread and use a torque wrench so as to not over-torque (aluminum heads). Buy these; it's just not worth messing around with anything less, and these seem excellent.