Search Results

Making lighter engines is in the agenda of all OEMs in order to make their cars lighter and to reduce CO2 emission based on regulations. On the other hand, the noise regulations are getting more stringent and the customer impression of interior sounds is still an important aspect in vehicle development. Vehicle noise legislation has been revised numerous times since it was first established in February 1970. The latest revision in EU legislation introduces a revised test method which is used to enforce diminishing noise limits in three phases (EU Regulation No. 540/2014). Since 2016 the noise limit for passenger cars has been 72 dB(A). It will be reduced to 70 dB(A) in 2020 and to 68 dB(A) in 2024. These vehicle pass by noise limits cascade down to limitations on engine noise. New engine designs face a trade-off between a lightweight design and fulfilling the NVH targets. The conventional design updates are done by adding ribs and usually mass to the engine.