It is a good idea if you measure your planned primitive survival electrical system and how much it surges or changes in voltage. Estimate the change in voltages over and above 120 Volts, then drop this amount of voltage or more as a minimum for what is planned to be delivered to tungsten bulbs for a planned normal 2000 Hr lifetime. The following nomograph is usefully when calculating how much additional drop in voltage is needed to get the intended longer lifetime. Adding the amount of surge above 120 V for the generator system to the delta needed for the long lifetime and subtracting this from 120 volts gives the average voltage one should run your tungsten bulbs at to get longer lifetime.

Offered by Mike.