[Maseratighibli]

RAC advice on the above subject recommends you change at 10, 000 miles or 12 months whatever comes sooner.
Now, if you do 5,000 a year why can't you change your filter evert 24 months.

[Santa]

For parts like filters, it's common to specify time or mileage as an interval. The manufacturers have to account for the owner who does 20,000 a year and the owner (like me) who does 5,000.

Other factors can come into play as well. If a lot of driving is done in dusty conditions, more frequent changes may be in order. If you go to the other extreme, a car that spends a year parked in a garage will not need a filter change at all.

[Maseratighibli]

Thanks for that, but it doesn't answer my question.
An air filter change surely should be based on contamination. Contamination received while the car is in motion. Ergo at 5k you won't have the equivalent 10k contamination so surely the manufacturer should not use a date as a bench mark, leaving aside the other points you make about conditions etc. Should be true of most wear and tear components, with perhaps oil being the exception. For example look at the difference between the service intervals for the Hybred Maserati Ghibli and the earlier non hybrid models going from 12 months to 24 months.To me it all looks like a wet finger in the air. Or put more bluntly a rip off.

[Rolebama]

I have seen engines destroyed because of leaving a 'clean' air filter in place because it broke up. They can dry out to the point where they just fall apart and bits get sucked into the engine. Mostly where the car sits stationary in rush hour congestion for hours every ay, especially in the summer. I would recommend an annual change regardless of low mileages.