Of these, heptane with 7 carbons causes undesirable engineknocking, so refiners try to blend in more smooth-burning octane with 8 carbons.
7个碳的庚烷引起不明原因引擎抽风。炼油厂尝试混入更多的8个碳的辛烷。
2
With lead and MTBE additives now phased out, spiking petrol with a small amount of ethanol raises its octane level enough to prevent the engine from "knocking" under load.