Whats the average mpg of '75 Camaros?

Your question is pretty vague. Does your Camaro have a 6cyl or V8? When was the fuel filter changed last? If a V8, does it have a 2v or 4v carb? Any aftermarket parts installed? Any changes to the exhaust system? All of these things factor into fuel mileage, including... your driving habits. In stock, new condition you could expect around 16-19mpg highway, 14-16 city. Hope that helps some.