The dealership is in the best position to provide advice on when a consumable item needs to be replaced.  They have had an opportunity to inspect the item and have the information at hand needed to provide this advice.

There are a number of factors that impact when a consumable item need to be replaced, and this can vary from vehicle to vehicle based on the individual use of the vehicle.

Consumable items are generally not covered under the warranty of the vehicle, as outlined in the General Exemptions section of the warranty policy, which can be found here.