* Engine size: The C20 came with a range of engine options (V6 or various V8s). Larger engines meant significantly lower fuel economy.
* Transmission: Automatic transmissions generally got slightly lower mileage than manuals.
* Condition of the vehicle: Proper maintenance, tire pressure, and overall vehicle condition greatly impact fuel economy.
* Driving style: Aggressive driving significantly reduces fuel economy.
* Payload and towing: Hauling heavy loads dramatically reduces MPG.
Therefore, there's no single answer. You'll find widely varying figures online, ranging from 8-15 MPG in real-world driving. Expect the lower end of that range, or even lower, under typical use conditions. The EPA estimates from that era are likely to be optimistic compared to real-world driving.
