Ingenuity abounds, it seems, when it comes to putting extra fuel into airplanes. Not all approvals are applicable to other aircraft models in a series, and some of the older STCs are no longer supported. If considering the purchase of an airplane with existing aux tank modifications, be sure to get all the paperwork and check out the availability of parts, if needed.
In all cases, the value of an auxiliary fuel system will be related to the existence of an STC holder that’s still in business. Orphan equipment adds little to resale worth. Check out the opinions on type-club forums to see what other owners say about their modifications. Extra fuel is worth a lot when you’re struggling to get home against a stiff headwind.
