That's a really good question and something not likely to be answerable in reality. Why? Because the sorbents have a specific capacity, and they follow what's called an adsorption isotherm; effectively, the capacity is lower at lower concentrations and higher at higher concentrations. On top of that, there's natural diffusion.
So if you live in a polluted area, the filter may be scavenging diffusing pollutants even when the system is off and car parked, affecting capacity. But if you drive through a more polluted area, it may still pull some more out because of the isotherm.
On top of that, some are really big/long, and some are pretty small. So the mass of adsorbent is variable.
Id argue that it is more marketing ploy in the end. That said, the use of activated carbon to remove organics is legitimate, and so to some extent, until the sensitivity of your nose states otherwise, this is a "comfort" capability that gets swapped at the recommended interval (12mo/12k???) or if you start noticing something different...
Its not a tough calculation to assume some airflow, some ppm of pollutants, some capacity per gram of carbon, and how much carbon is needed... and then notionally add that amount in the filter. I dont know the basis of calculation, so couldnt say if the true amount is grams or kilograms...