[criticalbass]

My '86 4.3 (It's a carbureted vortec!) sits in a 1/2 ton full sized Chevy pickup, and it gets 14 around town and 17 on the road. Something is very wrong to cause the poor mileage you are experiencing. Don't spend money on fuel saving devices right now. Diagnose and fix what's wrong, and if you have to pay a mechanic, do it before whatever is wrong does damage to something else. (too much fuel eats muffler systems, converters, sensors, etc., not to mention dollar bills) CB