4.6 seconds! Must be the M?
I believe this is the link,
https://www.caranddriver.com/reviews...v-first-drive/
"But this is America, so a 456-hp twin-turbo 4.4-liter V-8 provides the muscle in the xDrive50i. Its plateau of 479 pound-feet of torque starts way down at 1500 rpm and extends all the way to 4750.
We expect the sprint to 60 mph to take a short 4.6 seconds when the X7 is equipped with the V-8 and a still-respectable 5.5 seconds with the six-cylinder.