My '87 Sammy gets about 16 mpg. I'm on 32's with a locked rear axle, re-geared xfer case, and about 200 lbs of bumpers, skidplates, rocksliders, hi lift, tools etc. plus my 240 lbs on board. My buddy has a Sammy that is close to stock (235/75-15's with a Shackle Reversal) and he's getting in the high 20's in the summer, and the low 20's in the winter.