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? best models to buy, and this has since been an annual – and eagerly awaited – feature. In 1996, the website www.whatcar.com was launched. More recently, "What Car?" launched another print edition in 2006, published in India every two months, which subsequently became a monthly publication. "What Car?" was featured in the movie "Early Man" (2018), though titled "What Chariot?". Every year in January, "What Car?" hosts an awards ceremony, where it names the best cars in each sector of the car market, and an overall Car of the Year, with the Renault 20 receiving the inaugural award in 1978.