1 constant fuel consumption
is in the fuel consumption constant temperature, wind direction, wind speed and other environmental regulations objective countries, or remain in a vehicle speed in a chassis dynamometer on a flat road (road airport) (typically 60km / h, 90km / h, 120km / h three options), and then by ldquo; flowmeter method rdquo; or ldquo; carbon balance method rdquo; calculating an average of hundred kilometers. ldquo; carbon balance method rdquo; than ldquo; flowmeter method rdquo; more accurate.
By convention the foreign car market, the manufacturer announced fuel consumption typically speed of 90km / h at one hundred kilometers constant speed fuel consumption, and as one of the reference data to check against vehicle performance evaluation.