[junkyardjohn]

I'VE BEEN DRIVING & WORKING ON THESE OLD TRUCKS SINCE 1985. I'VE HAD INLINES, SMALL BLOCKS & BIG BLOCKS, 4 SPEEDS, 3 ON THE TREES & AUTO-MATICS. MY GAS MILLIAGE VARIED FROM 8 TO 12 MPG. HIGHER COMPRESSION MOTORS REQUIRE HIGHER OCTAIN FUEL TO RUN. IF YOU GET OVER 10 1/2 - 1 COMPRESSION YOU EITHER HAVE TO MIX YOUR OWN FUEL OR RUN RACING GAS OR AVIATION FUEL. (& I HAVE) IT GETS KINDA EXPENSIVE. NO ONE EVER UNDER ESTIMATES THEIR MILLIAGE OR HORSEPOWER. DON'T FORGET.. YOUR TRYING TO PUSH A BRICK SHAPED, 4000 POUND VEHICAL DOWN THE HI-WAY AT 70 MPH. I'LL PROBABLY GET SLAMMED FOR THIS AS SEVERAL PEOPLE CLAIM TO GET 18 20 OR EVEN 23MPG ON A SOMEWHAT STOCK SETUP. I CALL B.S. & FIGURE THESE PEOPLE WERE JUST NOT VERY GOOD AT MATH. IF YOU ABSOLUTELY NEED GAS MILLIAGE.. BUY A VOLKSWAGEN DIESEL. I HERE THEY GET 50 MPGs.