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? carry listings from other sources, dropping the 'Approved Used' branding. In October 2016, "What Car?" launched a new online car buying service called 'New Car Buyer Marketplace'. Built into the existing whatcar.com website, it lets readers buy discounted cars from dealers in their area who have signed up to a "What Car?" code of content. Users can add options, change trim and alter finance preferences to get a ‘live' price which dealers are committed to. "What Car?"'s 'Target Price' – a long-established recommendation of the most the magazine's mystery shoppers think someone should pay for a particular model – is