You won't find a single definitive number. To get a more precise estimate, look up the specific engine displacement (e.g., 2.5L or 2.9L) listed on your vehicle's paperwork or the sticker on the driver's side doorjamb and then search for EPA fuel economy estimates for that specific model year and engine. Websites like fueleconomy.gov (US) or similar sites for your country may offer this data.