You could get one of those hybrid electric/gas ones. I hear it only uses the gas at cruising speed. Personally though, I suggest the hydrogen powered sparrow. Assuming you get the basic tower insurance plan which basically allows you to spawn your sparrow in almost any location (assuming you have a clear view of the southern sky) with all components rematerialized, I always run it full speed at a group of enemies, then jump off and shoot it when it gets to them. There ain't no explosion like a hydrogen explosion to turn those cabal into kabobs.