The answer
Convert in two waves, and let the first wave prove the corridor. Convert the 10 busiest trucks on routes with a working CNG station now. Convert the other 20 at month 4 only if the first wave pays back within 18 months.
- Each truck pays where it can fuel. A converted truck nets about ₦1.4M a month and repays a ₦9M conversion in about 6 months.
- Diesel price is not what decides it. If the corridor cannot fuel trucks reliably, a converted truck nets about ₦65k a month, and converting all 30 loses about ₦224M. At ₦2,200 diesel it still loses about ₦111M.
- Staging is insurance with a price. It gives up about ₦91M if the corridor works, and cuts the loss from ₦224M to ₦75M if it does not. It beats converting everything once you put the odds of corridor failure above about 38%.
To convert all 30 now, you would need to believe the corridor fails less than 38% of the time. Test that cheaply first: time fills at the stations on your routes, get off-peak slots in writing, and speak to two operators already running dual-fuel.
In plain terms: the trucks and the gas are not the risk. Queuing for fuel is. Find out whether you can fuel before you buy.
1. Why gas, and why now
In May 2026 the National Bureau of Statistics put average retail diesel at ₦3,277 a litre, up 86% in a year. For a truck burning about 4,000 litres a month, every ₦100 on the price moves its bill by roughly ₦412,000. Since September 2025, lorries have paid ₦450 per standard cubic metre (SCM) of CNG, far below diesel for the same energy.
But a conversion is paid for up front, and borrowing is expensive: average maximum bank lending rates ran at 29–35% in 2026. The central bank cut its policy rate to 23% in September but called it a reset to market rates, and banks said they would not cut lending rates. So the saving has to beat the interest, and the real question is whether it can be captured at all. The client is an illustrative haulier with 30 diesel trucks on a Lagos–southwest corridor, not a real company.
2. When the corridor works, a truck repays its conversion in six months
The two worlds differ in three inputs that share one cause, fuelling reliability. A truck that cannot fuel at a CNG station runs on diesel, so less diesel is replaced, and it loses trips to queues. Everything else is held the same.
| Per truck, per month | Corridor works | Corridor fails |
|---|---|---|
| Share of fuel bought at CNG stations | 90% | 40% |
| Share of diesel replaced | 35% | 19% |
| Trips lost to queues | 0.05 | 0.4 |
| Diesel saved, net of gas bought (₦) | 1,607,299 | 387,793 |
| Maintenance (₦) | −100,000 | −100,000 |
| Queue losses (₦) | −20,000 | −160,000 |
| Weight penalty (₦) | −63,000 | −63,000 |
| Net benefit (₦) | 1,424,299 | 64,793 |
| Payback on ₦9M | 6.3 months | 139 months |
In hours: at five trips a month a round trip takes about six days (an assumption), so 0.05 lost trips is about 7 hours a month waiting at pumps, and 0.4 is about 58 hours, nearly two and a half days. The 19% is the one observed figure for diesel replaced. The access and queue figures are my assumptions. The conversion cost, litres per trip and trips per month come from one unverified operator post.
3. Diesel price barely moves the decision
Corridor works
Corridor fails
Source: author's model (V2 Summary sheet); NPV of converting all 30 now, ₦ million, 36 months, vs staying on diesel.
A fleet that cannot fuel loses money even when diesel is dear. A fleet that can fuel makes money even when diesel is cheap, and even if the conversion costs ₦20M a truck (+₦422M). The corridor decides the sign. The diesel price only changes the size.
4. Four plans, two worlds
B. Convert all 30 now
C. Staged waves
D. Wait 12 months
Source: author's model (V2 Summary sheet); NPV vs staying on diesel, ₦ million, 36 months.
The plans: A stay on diesel; B convert all 30 now; C staged, 10 now and 20 at month 4 if the gate passes; D wait 12 months, then convert all. In the failing world, plan C stops after the first wave because measured payback fails the gate.
- Waiting never wins. It beats staying on diesel only when the corridor works, and it trails B and C.
- Staging has a price and a payoff. It costs about ₦91M if the corridor works and saves about ₦149M if it fails. Cash tied up at worst falls from ₦270M to ₦213M if the corridor works and ₦90M if it fails.
- It is worth finding out. At 30% odds of failure, knowing the world in advance is worth about ₦67M.
5. What to do on Monday
| When | Action |
|---|---|
| Weeks 1–2 | Time fills at the stations on your three busiest routes, peak and off-peak. Get off-peak slots in writing. Find out what share of trips can fuel without a detour. |
| Weeks 1–4 | Get two or three named installer quotes for a heavy-truck dual-fuel kit. Speak to two operators running dual-fuel. Fix a financing quote. |
| Months 1–2 | Pick the 10 busiest trucks on routes with a station. Convert them. Log litres of diesel, cubic metres of gas, trips, queue time and downtime for every truck. |
| Month 4 | Convert the other 20 only if measured payback is 18 months or less (about ₦500k net per truck per month). |
| If the gate fails | Stop at 10 trucks. The most cash at risk is about ₦90M. |
6. What I know, what I assumed, what I don't
- Checked against sources: diesel and gas prices, the policy and lending rates, cylinder weights and the overload rules.
- Assumed: how well the corridor fuels trucks, queue losses, maintenance, margin per trip, the freight tariff, and the odds of corridor failure.
- Not yet known: a named installer's price for a heavy truck, and how much diesel gas replaces on real Nigerian trucks.
- Not modelled: extra diesel burned carrying about 1.2 tonnes of cylinders on empty return legs; the pilot should track it with telematics. If every trip were weight-limited, the weight penalty would rise from about ₦63k to ₦210k a truck-month: payback if the corridor works would stretch to about 7 months, and a failing corridor would lose about ₦82k a truck-month.
An earlier version recommended a five-truck pilot. Testing the model against itself showed that converting everything beat the pilot in every one-at-a-time test. That moved the question from 'which plan' to 'what decides it', and led to the staged plan above.
Sources
- NBS Diesel Price Watch, May 2026, via 21st Century Chronicle
- CNG prices (₦380 cars, ₦450 lorries): TheCable, Ecofin
- Policy rate: Nairametrics; lending rates: ThisDay
- Cylinder weights: Faber; overload and axle rules: Federal Highways Regulations 2018
- Fuelling access in 13 of 36 states: Associated Press, via ABC News