Long queues of cars are a common sight at petrol stations across Nigeria, but for some drivers turning to compressed natural gas, pumps are becoming a thing of the past. A fivefold increase in petrol prices since the rollback of fuel subsidies last year has convinced them to make the switch to CNG, which is much cheaper and far kinder to the environment. At the NIPCO Plc station on the outskirts of Abuja, the capital, business is also brisk for retrofitting cars to run on compressed gas. It’s...