Conversion Factors

Length
1″ = 25.4 mm
1 mile = 1.609 344 km = 0.999 998 survey (US statute) mile
1 mile (US statute) ≅ 1.609 347 km

Weight
1 lb = 0.453 592 37 kg

Volume
1 ci = 16.387 064 cc = 0.016 387 064 L
1 cu-ft = 28.316 846 592 L
1 gal (UK) = 4.546 09 L ≅ 1.200 950 gal (US)
1 gal (US) = 3.785 411 784 L

Cargo capacity is frequently measured according to three major standards (not always specified): SAE, DIN and VDA (block method) — the SAE typically giving figures 10–25% lower than the two European standards.

Power
1 hp ≅ 0.745 699 9 kW
1 hp ≅ 1.013 869 metric hp / Pferdestarke (PS) / cavalli (CV) / chevaux (CH)
1 PS ≅ 0.735 498 8 kW

Torque
1 lb-ft ≅ 1.355 818 Nm ≅ 0.138 255 0 kg.m
1 kg-m = 9.806 65 Nm

Measurements of power and torque are usually made to one of three standards: SAE J1349, 80/1269/EEC or DIN 70020. The SAE and EEC standards specify operating conditions of 99 kPa / 29.23 InHg of dry air and 25 °C / 77 F temperature. The DIN and Japanese JIS D 1001 standard are calculated at higher pressure (101.3 kPa / 29.33 InHg of dry air) and lower temperature (20 °C / 68 F), resulting in increased power, and DIN 70020 does not specify the status of accessories such as the engine fan and water pump, again resulting in a slight increase in measured power. Latest revisions to J1349 add more accessories such as power steering pumps not specified by 80/1269/EEC, but required for normal vehicle operation, resulting in further reductions in net power.

Pressure
1 psi ≅ 0.068 947 57 bar
1 atm (standard) = 1.013 25 bar
1 bar = 100 kPa

Fuel economy
1 mpg (UK) ≅ 0.354 006 2 km/L
1 mpg (US) ≅ 0.425 143 7 km/L
x L/100 km ≅ 235.215÷x mpg (US)