the engineer

Hi Dave Upon purchasing the vehicle new I insisted on 17" rims and that run-flats should not be fitted. The car arrived with Bridgestone Turanza tyres fitted on 17" rims, great. On the first day and a few miles away from the dealership where the road test roads are very good I noticed the road noise on our normal roads. I complained to the dealership, whereupon they road tested the car and found it to be in their words satisfactory. I asked for the advice of the ''Diesel Car & Eco Car mag'' who suggested a change of tyres to Goodyear Efficient Grip's. Before I changed the tyres I recorded sound pressure level readings over five specific roads at particular points. Followed by reading with the new tyres (after 200 miles to remove the new edges) the average reduction was 3.72 dB. Unfortunately, in reality it takes a reduction of 5dB to make a reasonable noticeable difference for the human ear. Hence my investigation into acoustic soundproofing, as I love everything else about the car. Graham the engineer.

From new my 2017 X1 has made excessive road noise, after a road test by BMW they advised that the noise is not excessive. £250 later on new tyres advised by a leading magazine, still the road noise is unacceptable. On the odd UK smooth good quality road I might find myself upon it's fine and I love the car, then back on the rotten roads as normal it's deafening. I'm looking at sound insulation any ideas anyone ??