Putting nine gallons less fuel in is going to be damn inconvienient when you run out. 

Trucking grain is all about payload.  Every little bit counts.  I can't get over how many trucks we've loaded over the years which weighed darn near 30,000 lbs empty, pulling tandem trailers.  Then they wonder why the guy with the 25,500 lb spread is "undercutting" their rates....well, because he can....he's hauling 10,000 lbs more payload every trip.