Ford 6.0 air filter - how long should it last?

[sreigle]

My 6.0 has the filter minder gauge under the hood that is supposed to show the percentage of clogging of the air filter. The truck has over 70k miles and this gauge still shows only between 5 and 10 percent clogged. I read somewhere to expect 75k to 85k miles on one filter if not running a lot of dirt roads.

I'm wondering if the gauge is faulty. The filter is not easy to get off and I doubt I'd be able to see inside the housing to see how it looks. Last time I checked Ford wanted $100 for the filter so I'm not anxious to change out the filter if it's not needed.

Any of you with the 6.0 have any experience with this?

Thanks.