I have a 91 RC, that I bought brandy new. Can't get over 15 MPG with it, with a stiff tail wind. Was my every day driver for 20 years, on and off road. Mine is a 318 TB auto. Never had any power, but I never got stuck in it either. went down lots of loneley logging roads in it, deer hunting in northern Wis.
I put lockouts on it when new, and never noticed any mileage difference. The little 318 has over 225000 miles on it now. The only major engine parts I had to replace, were the water pump, and timeing chain at 125000 miles. I replaced the computer, distributor, and the fuel pump, along with some sensors, and t-stats, and a few universals, and the speedo head at 172000. I take care of the ole girl.
I re-did the body in 2010, scouring 2 full factoy quarters, (very rare), and repainted it, new carpets, and some other interior stuff. I love the ole girl, I would never get rid of it. It rides like an old buckboard.
I have allways wanted to get rid of the computer controlled TB, and put in a 360 with a carb, and do away with the electronics, bur some of the components wont work without a computer. Heres a pic after re-duing the body.
barracudadave67
My son said he is going to convert it over to a Cummings Diesel, when I croak.
I never bought mine for mileage. I bought it for 4x4, and durabuilty.