Harley-Davidson Fat Boy mileage and running cost

The Fat Boy is rated at 18 kmpl (claimed mileage). Treat that as a ceiling: real-world figures are usually 15–25% lower.

Among the 40 cruisers we have reviewed it ranks 33th for mileage, 7 kmpl below the group average of 25 kmpl.

At Delhi's petrol price of ₹94.80 a litre and a claimed 18 kmpl, the Fat Boy costs about ₹5.27 per km in fuel. Ride 30 km a day and that is roughly ₹4,108 a month, or ₹49,296 a year, before servicing.

Spread over five years and 46,800 km, the Fat Boy works out to about ₹76.4 per km all-in, of which 7% is fuel and 88% is the purchase price itself. Resale value is not counted; expect roughly 50–60% of ex-showroom after five years for a well-kept example.

The quickest wins for the Fat Boy: keep tyres at the recommended pressure (under-inflation by 5 psi can cost 2–3 kmpl), shift up early and avoid idling at long signals.

Short trips hurt most. A cold engine on a 2 km run can return half its normal mileage; if that is your use, expect the low end of the real-world band.

Service on time. A clogged air filter or old spark plug shows up in mileage before it shows up anywhere else.