The short life span means you will have to replace them realistically before 10k miles. Great for race applications. If your motive is to not have the dreaded ''stuck plug'' you may as well do Autolite HTO plugs and change them every 10-12k miles and they will never seize in the heads at that interval. You'll need to replace any F/I plug at or around 10k anyway which means seized plugs are a non issue. Of course, I don't know your motive, just throwing this out there for you.