Dear Car Talk:

I like to do my own car maintenance, including replacing spark plugs.

I recently bought a set of NGK spark plugs online at a really good price. Then I had a thought -- maybe they were stolen or fake.

I did some research and found that they were made in China and were definitely fake. NGK's website provides details of the fake plugs and how to identify them. NGK warns that the fake plugs can cause serious engine damage and mileage would likely suffer.

The boxes holding the fake and real plugs are the same, and there are very small differences between the look of the plugs.

How do you protect against counterfeit car parts that can seriously damage a car? -- Steve



It's not easy, Steve. The internet has made buying auto parts easier than ever.

It's also made buying counterfeit parts easier than ever. I suppose the best advice is to simply beware of a deal that sounds too good to be true.

The term "buyer beware" was first invoked in the Pleistocene Era, when a caveman named Ook sold his neighbor, Grog, a club that turned out to be hollow. Grog went back to try to beat Ook over the head with it, but that had little effect. So, Grog invented the term "buyer beware" and later went on to found the Better Caveman Bureau.

And while the items that are sold and the way they are sold have changed over the millennia, two things have remained true: Humans are suckers for a bargain, and there's always someone looking to take advantage of the fact that humans are suckers for a bargain.

I assume you were shopping for the lifetime iridium electrode plugs, Steve. You certainly don't want to install anybody's cheap, counterfeit spark plugs because if the electrode breaks off or if the plug gets stuck in the cylinder head, the repair will cost you at least 200 times what you saved by finding a "bargain."

Even if the bogus plugs fail in a non-catastrophic way, you still have to redo the whole job, which is time-consuming on modern cars because the spark plugs are often hard to reach.

My advice is to start by comparing prices at known, reputable sellers. If you look around for the NGKs from well-known auto parts retailers, you'll find they generally sell online for about 10 or 15 bucks a plug for most cars.

So, if you find a set of four for $12 from Rudy's House of Spark Plugs, that's a pretty good clue those are fake. If it sounds too good to be true, it probably is, Steve. Especially on the internet.

P.S. You might want to check that Gucci handbag you bought online for your wife. Especially if it says "Goochie" on the logo.