Kevin,

 

Understood, I agree, trading fuel for other (less useful) weight can be a good tradeoff.

 

However, in a plane that’s inherently a bit nose heavy, the “ounces” have to come from the nose - ahead of the CG (which is pretty much right at the pilot seat).  It’s not possible to remove weight from behind the CG (most of the plane) and replace it with fuel (at the CG).  Rather, anything you remove from behind the CG has to be replaced with some other weight behind the CG (i.e. no net savings).

 

It is potentially possible to move some other things further back in the plane (longer moment arm), to help offset the CG effect of anything removed and thus save some total weight (which could then be replaced by more fuel).  However, that is how we got on the “batteries in the back” conversation to begin with.  It would normally be better to have the batteries near the starter and alternator(s) (in the front).  However, in a nose heavy plane, if the batteries are not located in the back, then some “other weight has to located there and/or additional net weight to counter-balance a firewall mounted battery, thereby increasing total weight (and reducing total available fuel load – opposite Brent’s suggestion in this case).  The point being that tail weight (batteries or anything else behind the CG) can not be traded for fuel in a nose heavy plane.

 

Rick