Fuel range planning for motorcycle rides: the maths riders skip

Nothing sours a good ride like the last 30 kilometres spent doing the arithmetic on a reserve light instead of enjoying the road. Fuel planning takes two minutes at the planning stage and removes the problem entirely.

Your range is not your tank size

Three separate deductions sit between the number on the spec sheet and the distance you can actually ride.

Unusable fuel. Not all of the tank reaches the fuel pump, particularly on a bike being leaned about. A portion of every tank is unavailable.

Consumption reality. Manufacturer figures come from steady-speed testing. Your figure comes from your right wrist on the roads you actually ride.

Reserve you should not be spending. The bottom of the tank is your margin for a closed servo or a detour. If you routinely use it, you do not have a margin.

A practical planning rule: usable range ≈ 80% of theoretical range. Work out what your bike really does per tank on a good ride, take 80% of it, and use that as your planning distance. The reserve light becomes information rather than an emergency.

Curvy riding costs more fuel than you think

Riders plan fuel using consumption figures learned from commuting, then wonder why the range collapsed on a mountain day.

Twisty riding is expensive because:

• You are accelerating out of corners constantly rather than holding a steady throttle.
• Lower gears and higher revs.
• Braking converts fuel you already burned into heat.
• Climbing costs, and descending does not refund it.

Depending on the bike and how enthusiastically it is being ridden, a genuinely twisty day can cost meaningfully more per kilometre than a highway cruise. If your planned route is properly curvy, plan the fuel with pessimistic numbers.

The second-order effect catches people too: on twisty roads you cover far fewer kilometres per hour, so a tank lasts fewer kilometres and the distance to the next town takes longer to cover. Both move the same direction.

Rural fuel: hours matter as much as distance

City riders plan fuel as a distance problem. Once you are properly out of town it becomes a timing problem.

• Small-town servos keep small-town hours. A pump that closed at 4pm on a Sunday is not a fuel stop, however conveniently placed.
• Some remote sites are card-only after hours, some are cash-only, and card readers in low-coverage areas fail. Carry both.
• A single pump in a small town is a single point of failure — out of order, out of fuel, or closed for a funeral.
• Long weekends drain rural fuel supplies in tourist areas.

Rule for remote riding: build the ride around the fuel stop, rather than hoping to fit one in. Make it a waypoint, arrive with enough in the tank that you could reach the next one if this one is shut, and check hours before you leave if the gap is serious.

Group fuel arithmetic

In a group, the useful range is not yours:

Group range = smallest tank present − whoever forgot to fill up last night.

There is always one. The practical answers are unglamorous:

• Everyone fills the night before or at the meeting point. State it in the briefing.
• Fuel every 150–180 km regardless of what anybody claims their range is.
• Everyone fills at every fuel stop, even if they are half full. Splitting the group across two fuel stops is how you lose an hour.
• Fuel stops are also break stops. Combining them saves a stop.

More on running a group cleanly in the group ride guide.

Planning it properly, in practice

When you build the route:

1. Note your planning range. 80% of realistic, using pessimistic consumption for twisty roads.
2. Find the longest gap between fuel on the route. Most planners will show you fuel stops along the route rather than making you hunt.
3. If the gap exceeds your planning range, add a fuel waypoint so the route is built around it. A fuel stop as a waypoint changes the road you take; a fuel stop as an afterthought is a 20-kilometre detour.
4. Check the timing of the remote ones. Will you arrive after closing?
5. Sanity-check the return leg. The classic failure is planning the outbound carefully and running home on fumes.

The 10-litre rule for touring

For multi-day riding in unfamiliar country, a simple habit: never pass a servo with less than a third of a tank left, even if the map says there is another one soon. Fuel that exists on the map does not always exist in reality, and the cost of an unnecessary five-minute stop is nothing compared to the cost of a wrong assumption.

What to carry

• A card and cash. Both fail in different places.
• A rough idea of your consumption. If you do not know it, work it out on the next tank: fill, reset trip, ride normally, fill again, divide.
• On genuinely remote routes, a way to call for help that does not depend on mobile coverage. Fuel exhaustion in remote country stops being an inconvenience and starts being a safety issue, which is where crash detection and location sharing stop covering you.

Two minutes at the planning stage. Then you can spend the last 30 kilometres looking at the road instead of the fuel gauge.