Question

How often should you replace spark plugs in a car?

How many miles can you go before replacing your vehicles spark plugs?

Answer 1

Spark plugs should be good for at least 100,000 miles before needing replaced.

But it doesn't hurt to take one of the spark plugs out sooner at 50,000 miles and check for any fouling of the plug.

If one of the spark plugs is fouling then you should replace them all.