Exhaust gas gas is undesirable, noxious, or toxic substances, such as carbon monoxide (CO) from incomplete combustion, hydrocarbons (properly indicated as CH, but typically shown simply as "HC" on emissions-test slips) from unburnt fuel, nitrogen oxides (NO) from excessive combustion temperatures, and particulate matter (mostly soot). Exhaust gas temperature (EGT) is important to the functioning of the catalytic converter of an internal combustion engine. It may be measured by an exhaust gas temperature gauge. EGT is also a measure of engine health in gas-turbine engines (see below). During the first two minutes after starting the engine of a car that has not
What Car? car if they drive it gently and stick to speed limits, but don't resort to any unrealistically slow acceleration or special hypermiling techniques. These True MPG figures are published alongside the official government fuel economy data, that car manufacturers are legally obliged to include in brochures. In June 2012, "What Car?" launched an online car buying service called 'What Car Approved Used', which it claimed provides "peace of mind" to car buyers, by endorsing the "10 Points of Difference" promoted by the "National Franchised Dealers Association". The agreement came to a close in July 2015, and "What Car?" began to