A motorcycle’s fuel efficiency (often measured in miles per gallon or kilometers per liter) and its range on a full gas tank are essential considerations when buying a motorcycle, especially if you plan to use it for commuting, long-distance rides, or touring.

Here’s how to assess these factors:

1. Check Manufacturer Specifications: Begin by looking up the manufacturer’s specifications for the motorcycle model you are interested in. Most manufacturers provide information about the motorcycle’s estimated fuel efficiency (in mpg or km/l) and the fuel tank capacity (in gallons or liters).

2. Real-World Fuel Efficiency: Remember that the manufacturer’s stated fuel efficiency figures are often based on ideal conditions and may not accurately reflect real-world riding. You can check online motorcycle forums and reviews to see what riders report for fuel efficiency.
3. Calculate Range: To determine the motorcycle’s range on a full tank, multiply the fuel tank capacity by the motorcycle’s fuel efficiency. For example, if a motorcycle has a 4-gallon (15.1-liter) fuel tank and gets 45 mpg (19.1 km/l), the estimated range would be 180 miles (290 kilometers) before needing to refuel.
4. Consider Riding Style: Remember that your riding style, speed, and terrain can significantly impact fuel efficiency. Aggressive riding, high speeds, and hilly or windy conditions can reduce fuel efficiency, while conservative riding can improve it.
5. Fuel Type: Confirm the fuel the motorcycle requires (e.g., regular unleaded, premium unleaded). Using the recommended fuel type can help optimize fuel efficiency.
6. Additional Factors: Some motorcycles have features like adjustable riding modes that can affect fuel efficiency. For example, an “economy” mode may optimize fuel consumption for better mileage.
7. Test Ride: If possible, take the motorcycle for a test ride and pay attention to the fuel gauge during your ride. This can give you a practical sense of its fuel efficiency in real-world conditions.

8. Carry Extra Fuel: If you plan to ride in remote areas where fuel stations are scarce, consider carrying extra fuel in portable containers to extend your range.

Remember that while fuel efficiency and range are important factors, they are just one aspect of motorcycle ownership. Considering the motorcycle’s overall suitability for your riding needs, comfort, maintenance costs, and other essential features would be best.