Autonomia por Tanque

Tank range: formula and planning

Your range on a full tank is nothing more than volume multiplied by consumption: range = tank(L) · consumption(km/L). Example: a popular car with a 50 L tank doing 12 km/L gets you 600 km on a full tank. Keep about 10% in reserve as a safety margin, because most cars trigger the low-fuel light while there are still 5–8 L sloshing around in there. With a modern diesel, running it close to empty can clog the DPF (diesel particulate filter) and draw air into the fuel pump.

Applications

It comes in handy when you're planning a road trip and want to map the gas stations along the way, picking a strategic stop on a long stretch with no service, steering clear of an empty tank in the middle of nowhere, or just comparing models. A Honda Civic with a 50 L tank doing 13 km/L gives you about 650 km. A Chevrolet Onix with 44 L doing 14 km/L gives roughly 616 km, so almost the same range out of a smaller tank.

FAQ

Why doesn't the actual range match the calculation? Real consumption swings around with traffic, the AC, how loaded the car is and how you drive. Plan on landing 10–20% below the optimistic spec.

Is it safe to run the tank to zero? No. The fuel pump relies on the fuel itself to stay cool, so running dry wears it out and tends to suck up the gunk that settles at the bottom of the tank.

Does the reserve light come on at the same level for every car? No. It's usually somewhere around 10–15% of capacity, but each manufacturer sets it differently, so check the owner's manual.