it really depends on how you drive it , the size of the engine, if it is an automatic , or standard transmission , if it is in good mechanical condition, and has had a recent tune up. Considering the vintage , I would expect the mileage to be on the low side (8-14 city mpg) trucks of that vintage were not the greatest for fuel economy.
Most fall in the 8 - 12 mpg range, while a few get more and a few less
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