Our Extended Warranty covers airends and limited other components, but too often the objections are that it is not possible to follow the guidelines of routine fluid and filter maintenance every 6 months or 500 hours. By keeping to this maintenance schedule it will keep the compressor, airend, fluids and major components in almost new condition instead of sitting for extended periods in varying temperatures, varying humidity and either high or no cycling.
Would you prefer to either
(A) purchase a warranty, be able to choose your maintenance parts, but at OEM recommended intervals
(B) use OEM parts @ OEM recommended intervals where the warranty is free.
The alternative is to perform maintenance when its convenient and let the machine die at its own pace.