I use an older model Garmin Streetpilot GPS unit in the car. Normally it just sits in the glovebox as I usually know where I'm going and don't need to use it.
The audio volume level from the GPS is calibrated in steps from 0 - 10. In my last V6 (petrol) Vectra, a car which I considered a pretty quiet and refined cruiser, I used to have the volume level set at 5. This was perfectly audible at motorway speeds without being intrusive at lower speeds.
I've been driving a 2.0 diesel Audi A4 Avant recently and found I had to increase the volume level to 7 before I could hear the output. Surprising, as despite the diesel engine, the Audi seemed a pretty quiet machine and I didn't expect to increase the GPS sound output to hear it clearly. I can appreciate that estates are normally slightly noisier than saloons, but there appeared to be more road noise in the Audi and a low frequency 'growl' from the engine.
I've never owned a diesel car until I bought my E220 and I'm still less than enthusiastic about the clattery nature of the 4 pot diesel engine at low speeds. No problem in the cruise though, where it's a pleasantly relaxing place to be. When I used my Garmin GPS unit in the E class, I was pleasantly surprised to find that the volume could be set down to level 4.
So, according to my unscientific test, an E220 is slightly quieter than a Vauxhall Vectra, much quieter than an Audi A4 - and I'm enjoying my E Class more as time and the miles go on
The audio volume level from the GPS is calibrated in steps from 0 - 10. In my last V6 (petrol) Vectra, a car which I considered a pretty quiet and refined cruiser, I used to have the volume level set at 5. This was perfectly audible at motorway speeds without being intrusive at lower speeds.
I've been driving a 2.0 diesel Audi A4 Avant recently and found I had to increase the volume level to 7 before I could hear the output. Surprising, as despite the diesel engine, the Audi seemed a pretty quiet machine and I didn't expect to increase the GPS sound output to hear it clearly. I can appreciate that estates are normally slightly noisier than saloons, but there appeared to be more road noise in the Audi and a low frequency 'growl' from the engine.
I've never owned a diesel car until I bought my E220 and I'm still less than enthusiastic about the clattery nature of the 4 pot diesel engine at low speeds. No problem in the cruise though, where it's a pleasantly relaxing place to be. When I used my Garmin GPS unit in the E class, I was pleasantly surprised to find that the volume could be set down to level 4.
So, according to my unscientific test, an E220 is slightly quieter than a Vauxhall Vectra, much quieter than an Audi A4 - and I'm enjoying my E Class more as time and the miles go on
er; maybe time to try the ol johnsons ear buds.... make sure the ol lugs are squeeky b4 you blame munchen's finest! 
