According to my Owner’s manual I should replace my air filter at 30,000 miles or 36 months. It’s time for me to change it, so I just removed and inspected the old one. It looks very clean to me. I’m going to replace it anyway, but I’m wondering if it’s ever okay to NOT change an air filter if it looks okay - or is there dirt in there that I probably can’t see.
The dirt that can cause the problems is very fine, so it might still be ‘dirty’. That said, you may just drive in a very clean area. Regardless, it’s worth changing, they’re not much $$.
If you put the effort into opening it just replace it. They are extremely cheap.
Remember the filter itself has a design life and the material can degrade and hole can form introducing all sorts of contaminates into your engine.
For every gallon of gas your car consumes…it’ll consume 10,000 gallons of air…Change it.
I usually change my filters LONG before they’re due…and they usually need it too.
It looks very clean to me.
Which means you have dirt the same color as the filter. 
That white dirt is really difficult to see…
After awhile the filter material will start to blow off but it usually takes longer than 30,000 miles. Change it and don’t have a worry.
Are you sure you were looking at the intake side of the filter? If you looked at the top of the filter or exit side, it should be clean as new. But if you looked at the bottom or intake side, it should be fairly dirty with at least some bugs on it.
“The dirt that can cause the problems is very fine, so it might still be ‘dirty’.”
But there’s over 1000 times more particles too small to see than those you can see. Even though you can’t resolve each individual particle, you can easily see thousands of them agglomerated together. I change the filter when more than just the ends of the pleats are dirty.
I took out the air filter and looked at both sides. It looked very clean on each side. No bugs and no dirt that I could see. Since the OP I’ve gone ahead and changed the filter. When I compared the new one to the old one, there was a difference in color - of course the new one was slightly whiter, therefore cleaner looking.
I suppose it’s like a timing belt. Change it to prevent a problem instead of trying to save money now and end up losing some later.
“I suppose it’s like a timing belt.”
Except it is a lot easier and cheaper to change