Broadleaf forest. Broadleaf forests are the dominant habitat of the UK and most of temperate northern Europe. There's little left of Britain's ancient wildwood, but isolated pockets of oak, beech and mixed deciduous and evergreen woodlands are scattered across the continent, and dictate its biodiversity.
Engine pinging also refered to as pinking, detonation or knocking. Pinging can be anything from a loud knocking noise to a soft tinkling sound that is emitted from the engine. If an engine has a tendency to ping, it usually becomes first audible when operated in the lower rpm range and during acceleration.
EGR operates when conditions exist that cause pinging or valve clatter. A valve opens and circulates exhaust gas into the intake manifold to cool the combustion process. Exhaust gas is very low in oxygen. Adding exhaust gas to the fuel/air mixture, helps lower cylinder temperature.