Throughout this site we use many technical terms, and given the breadth of readership our site enjoys, sometimes we are remiss and incorrectly assume everyone knows what we are referring to. For those that do not, here are some explanations of the technical terms use.

Mixture Strength

The ratio of air to fuel. The chemically correct mixture strength for petrol is usually 14 or 15 to 1, depending on the blend, and thus the chemical composition of the petrol, but other combustible fuels used alone, or in a blend, may have quite a different ratio. Alcohols, for example, have a ratio of 7 or 8 to 1. Mixtures having less air than the chemically correct ratio are rich; those with more air are weak. Weaker mixtures are sometimes used for economical cruising under low power conditions.