Denso vs. NGK 4912 Spark Plugs? Are Amazon or Rock Auto problematic for 'fakes'?

I use RA quite frequently and have purchased dozens of sets of Denso plugs. Never had a counterfeit.

Many people believe a spark plug is just a spark plug, but I also know I've never had a skip or miss after installing a new set of Denso plugs in a Prius.

 

You just can't trust rock auto any longer. I had used them in the past, and had no issues.
But they are using more and more of the cheap chinese crap. Like pretty much everyone else, sadly.

I ran ngk once because autozone didn't have the Bosch plugs. They only lasted a few thousand miles
before they started missfiring. I replaced them with the Bosch plugs and haven't had any failures.
Just check the box and make sure they aren't made in china.

Denso have been very good plugs. Getting they from the deal will cost a little more, but the chance of
getting the cheap chinese copies, is pretty much zero. They last over 100,000 miles, how often do you think
you'll need to replace them???

 

How much is the savings, say an inexpensive bottle of wine, every 12 years or 120k miles?

I typically buy plugs from a local automotive place, a dedicated automotive place. With our ‘10 though, the Denso’s were $2~3 CDN per plug cheaper, through dealership. Worth a call.

 

Given their loooonnnnnggggg change interval, spark plugs is not the item to try to save money on. Buy it from the dealership. Last fall, I was able to buy some for $13 a piece with free shipping.