Whats the miles per gallon on a 1990 Chevy Cheyenne?

The miles per gallon (MPG) for a 1990 Chevy Cheyenne varies significantly depending on the engine size and configuration (e.g., 2WD vs. 4WD, transmission type). There wasn't a single engine option.

You'll find a range from approximately 10 MPG (for larger V8 engines and 4WD) to perhaps 16 MPG (for smaller V6 engines and 2WD, under ideal conditions). The actual MPG will also depend on driving style and vehicle condition.

To find a more precise estimate, you need to know the specific engine size (e.g., 4.3L V6, 5.0L V8, 5.7L V8, 7.4L V8) and drivetrain of the particular 1990 Chevy Cheyenne you're interested in. You might find this information on the vehicle's VIN plate or the owner's manual.