Why unit conversion matters in road transport
International transport mixes metric and Imperial data. A vehicle sheet may show kilograms and bar, while a customer document uses pounds and psi. Fuel figures are especially risky because US and Imperial gallons are not the same size. Record the source unit first, convert with the full factor, and round only the final result.
Exact factors worth keeping
- 1 mile = 1.609344 km.
- 1 inch = 25.4 mm.
- 1 lb = 0.45359237 kg.
- 1 US gallon = 3.785411784 litres.
- 1 Imperial gallon = 4.54609 litres.
- 1 bar ≈ 14.5038 psi.
Temperature needs an offset as well as a multiplier: °F = °C × 9/5 + 32, while °C = (°F − 32) × 5/9. For example, 20 °C equals 68 °F.
L/100 km versus MPG
Fuel consumption and fuel economy move in opposite directions. A higher L/100 km value means a lower MPG value. Use **US MPG = 235.214583 ÷ L/100 km** for a US gallon and **UK MPG = 282.480936 ÷ L/100 km** for an Imperial gallon. A truck using 30 L/100 km therefore returns about 7.84 US MPG or 9.42 UK MPG. Writing only “MPG” leaves an avoidable ambiguity.
A reliable conversion workflow
- Copy the value and its unit together from the source document.
- Choose the destination unit, including the correct gallon standard.
- Calculate with the complete conversion factor.
- Round for the job: 0.1 km may suit routing, while cost and fuel reports often need two decimal places.
- Keep the unit beside every result in a quote, CMR attachment or fleet report.
The truck unit converter performs the arithmetic quickly. It cannot decide whether an unlabeled gallon is US or Imperial, so confirm the source before using the answer commercially.
Final sense check
Check whether distance began in miles or kilometres, whether the gallon was US or Imperial, whether pressure is gauge or absolute, and whether a comma or point is the decimal separator. Most serious conversion errors start with one of these details, not with difficult mathematics.