- in our sound-level testing, we found that the 2019 bmw x7, the automaker's newest and largest suv, has a remarkably quiet interior.
- the x7 is quieter than every suv we've tested apart from the bentley bentayga, which costs twice as much.
- we test for interior sound-pressure levels using sophisticated sound-level measuring equipment.
one of the characteristics that often separates truly luxurious vehicles from the merely expensive is the amount of noise that makes its way into the cabin, particularly when traveling at highway speeds. it takes considerable engineering effort (and cost) to gird the cabin against all of the various potential sources of audible bother: wind rush, tire thrum, suspension clunks, outside noise sources such as passing vehicles, or the engine, transmission, and driveline themselves. and it's something that bmw has positively nailed in its newest and largest suv, the x7.
at c/d, we use a handheld brüel & kjær class 1 sound-level meter (priced as much as a nice first car) to measure interior sound-pressure levels at idle, at wide-open throttle, and while cruising at a steady 70 mph. that last data point is the one we're focusing on in this case. it's a number that tends to correlate well with the comfort of long-distance travel, something that's certainly true in the x7's case.
we tested both six-cylinder 40i and v-8 50i variants of the x7 on two different kinds of 21-inch all-season tires, and both came in at the same 64-dba reading. below, you'll see that it makes the x7 a standout among suvs (only the twice-as-expensive bentley bentayga is quieter). but it's also more silent than even many of what we think of as the typical purveyors of quiet, such as the mercedes-benz s-class and the lexus ls, which are pushing far less air than the mammoth x7.
also, allow us to remind you that this is a logarithmic measurement, which means small numerical differences make a big deal; every 3-db increase represents a doubling of the sound pressure.
and one more note: we're only comparing data taken from our primary test facility in michigan, because the road surface at our california track is smoother and measures quieter.
surprisingly, the x7's extensive press kit doesn't spend many words describing what went into achieving the x7's silence other than mentioning its laminated windshield and front side glass. we reached out to a spokesperson who, unfortunately, has yet to provide any additional detail. but the results below speak for themselves.
interior sound level at 70 mph (dba)
- 2019 bentley bentayga v-8: 61
- 2019 bmw x7 xdrive40i: 64
- 2019 bmw x7 xdrive50i: 64
- 2019 audi q8: 64
- 2017 mercedes-benz gls450: 65
- 2017 bentley bentayga: 65
- 2018 lincoln navigator: 66
- 2018 lexus lx570: 66
- 2016 cadillac escalade platinum: 67
- 2019 porsche cayenne s: 69
- 2019 audi a8l: 64
- 2018 mercedes-maybach s560: 65
- 2011 rolls-royce ghost: 65
- 2018 mercedes-benz s450: 66
- 2018 lexus ls500 f sport awd: 66
- 2018 tesla model s 100d: 68
don't forget: father's day is sunday, june 16