Petrol

Petrol is the plain liquid fuel people mean when they talk about filling cars, motorcycles, and small engines at the pump. By our assessment, its strength is obvious: it is the standard fuel for a huge share of spark-ignition engines, so it is easy to understand, easy to find, and central to everyday transport. The downside is just as concrete, because it is a fossil fuel with emissions and it asks for storage and handling care. In practice it is unglamorous, familiar stuff — nozzle, cap, smell, payment, done — and that is exactly the point. It sits alongside diesel, LPG, and electric charging as one of the basic ways vehicles get moving. Petrol is not a product with features so much as a commodity with a very large footprint.