unloaded she gets about 10mpg, loaded if I had to guess I would say 5mpg maybe 8. I did just pick up a spicer 5831 aux. trans with a .74 OD so my unloaded figures I am hoping will jump to around 15mpg. I've got a good pic of me pulling a 3020 ,which is one size smaller than a 4020, in my gallery.