Per most manufacturers' instructions, you should replace your refrigerator's water filter at least once every six months. If your water tastes "off," you should consider replacing the filter even if it hasn't been six months.
One every month if you have allergies.
Check it at each oil change, and replace when dirty.
you should only need to replace your fuel filter about every 45-60k miles. Check your service manual for scheduled maintenance.
GE recommends that you change your refrigerator water filter every 6 months, or if you are a heavy user, when you notice that the water quality has diminished.
Depending on how much you drive your car should be how often you change your air filter. Sources say you should change it when you go to get your oil changed cause they both last about the same time.
Replace it every 36,000 miles.
under the van, in the center.
If it has a replaceable filter replace it every 50,000 miles.
every 5 to 10 thousand miles
Your air filter should be changed each time you have a oil change or perhaps a tune up which should be every 6 months.
How often should you change the fuel filter?
If it is replaceable then replace it every 75,000 miles.