Back in 1980, I towed an 18 foot backhoe trailer with three mobile home axles from central California to Nashville Tennessee with a 1970 Cadillac Fleetwood Brougham with a 472 engine, with everything we owned stuffed inside a home-built box.. A truck scale in Nevada made us buy an "over-wide" permit, since the axles were a few inches over the limit. A trip across the scales during the permit process gave a gross combined vehicle weight of 16,700 pounds- - - -with a bit over 10K on the trailer axles. The old Caddy got 5 MPG for 2500+ miles. My wife was following, driving a 59 Suburban with a 1970 307 V8 engine and a SM 420 trans and towing a Datsun 510 station wagon. Both of those vehicles were crammed full clear to the roof. The Burb got 10 MPG- - - -drive 100 miles- - -gas up- - -"rinse and repeat!"
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!