Off-road capabilities, rivals

be mistaken for an electric vehicle.

It is silent, throbbing gently and making the faintest purr only when under extreme acceleration, and smoothly indifferent to imperfections in the road, thanks in part to the sophisticated air suspension system. The eight-speed transmission, connected to an all-wheel-drive system that includes rearwheel steering, is unintrusive and seamless.

I experienced no difference whatsoever — in wind noise, road noise or vibration — between 50 mph and twice that. (The Cullinan boasts an electronically limited top speed of 155 mph. I’m sure it’s kittenish at that velocity, too.)

The extreme silence — reportedly the result of specialized foam in the front wheels, laminated glass and hundreds of extra pounds of sound-deadening materials — allows the “bespoke audio” and

maximum perfection.

I cued up Handel’s “Water Music” and set the navigation, one of the best I have ever experienced, for a destination 120 miles to the north. Two movements later, it seemed, I had arrived.

The 30-gallon gas tank allowed me to get there without refueling — not entirely a surprise for a tank that size, except that the Cullinan consumes fuel at an average rate of 14 miles per gallon. (The Cullinan MSRP includes a $2,600 “gas guzzler” fee.)

On the return trip, I decided to test the off-road capabilities. Somewhere in the Tehachapi foothills, near Willow Springs, I left the highway for a stretch of unpaved side road, engaged the “off road” mode and allowed the Cullinan to be a real SUV.

First I assayed a quarter-mile of sand. Then I pushed a button to raise the vehicle and increase the ground clearance, and climbed a rocky hill. On the other side, I engaged the automatic hill descent system and let the Cullinan apply the correct amount of braking to bring us safely to level ground again.

Then I turned around and went back up the opposite way, enjoying the Cullinan’s quiet, capable demeanor. It kept calm, and carried on, until near the top, when its street tires spun and struggled

top. Once over, I returned to the sandy road and drove a few miles through the tumbleweeds and sage brush.

It’s possible that a bolder driver could have done more with the rough stuff than I did. But I was alone, and off the cellular grid, and a voice in my head kept saying, “Dude, you remember this is a $400,000 automobile, right?” (That’s with various options; the base is $325,000.)

Perhaps mindful of its own MSRP, and the concurrent high cost of repairs, the Cullinan is equipped with an impressive suite of sensors to help the driver avoid scraping the curb, hitting parked cars or backing into pedestrians.

The backup camera view can even be adjusted, from the infotainment screen

concern — when backing around a tricky obstacle, for example.

But the Cullinan does not park itself, and seemed to be missing some of the driver aids that one would expect from such an advanced, expensive vehicle. Though the vehicle does come equipped with adaptive cruise control, it does not include other semiautonomous driving technology, now standard on most luxury vehicles, that can make an inattentive or irresponsible driver safer on the road.

And I was troubled to see that, on the car I borrowed, the lovely Spirit of Ecstasy statuette that sits on the Cullinan grille did not retract and then reemerge when directed.

On the other hand, the Cullinan comes standard with “self-righting wheel centers,” which means the double-R RollsRoyce emblem is always right side up when the car is parked.

Rolls is coming very late to the SUV game. Having held out long enough to watch the arrival and sales successes of Porsche’s Macan and Cayenne, Maserati’s Levante, Alfa Romeo’s Stelvio, Bentley’s Bentayga, and even the Lamborghini Urus we reviewed here recently, Rolls is the last luxury brand but Ferrari to put a utility vehicle into its line.

Someone who is not a buyer for this car may ask, reasonably, who is the buyer for this car? BMW-owned Rolls-Royce, which just completed its best sales year ever, says that fully half of the buyers of its new SUV have never owned a Rolls before, and that the average Cullinan customer already owns

- ers are probably not asking “How much is it?” but “How good is it?”