Which? Car reveals the Top 10 quietest cars you can currently buy.
When Which? compared all the cars it has tested since 2006, it found that the most refined cars of all are made by Mercedes-Benz and Lexus.
Luxury diesels and hybrids dominate
Luxury cars dominate the chart, with eight of the top 10. Large 4x4s make up the remainder.
Another surprise is that there are no pure petrol-engined models in the top 10. Diesels dominate the listing, mostly because the engines are spinning at comparatively low revs at the motorway speeds where Which? testers measure noise levels. The quietest diesel of all is the Mercedes-Benz S350 CDI.
Hybrids also make a significant appearance, with the Lexus LS600h taking equal top spot, and two other hybrids also scoring top 10 slots. Included is the new Audi A6 2.0 TFSI Hybrid, which has just gone on sale in the UK priced from £43,480.
Top 10 Quietest Cars: the full list
1= Mercedes S350 CDI – 63.3dB
1= Lexus LS 600h L – 63.3dB
3. Audi A8 4.2 TDI Quattro – 63.7dB
4. BMW 730d – 63.8dB
5. Mercedes GL320 CDI – 64.3dB
6. BMW 335d coupé – 64.4dB
7. VW Touareg V6 TSI hybrid – 64.5dB
8. BMW 530d GT automatic – 64.6dB
9. Audi A6 2.0 TFSI hybrid – 64.7dB
10. Mercedes E350 CDI – 64.9dB
How we measure cabin noise
To make sure we have the most realistic measurement of interior noise, we use a sound level meter to measure the dB level inside the cabin centre at motorway speeds with a half load and standard summer tyres. We take the measurement travelling in both directions on the motorway and calculate the average figure.