If there’s justification in recasting the bigger of BMW’s two GT cars as a 6 Series rather than a 5 Series, it may be that it better prepares you for the fact that, dynamically more than anything else, this remains a luxury car first and foremost rather than some kind of extra-large middleweight executive saloon.
Simply put, as something both to drive and be driven in, the 6 Series GT is at least halfway to a 7 Series limo; probably slightly more than halfway, if you had to be absolutely specific.
Despite its M-Sport-specification 19in alloy wheels and run-flat tyres, our 630d GT test car rode surprisingly well – although not without a little bit of rumble over coarse tarmac, or without a slightly firm, hard edge over sharper lumps and bumps.
The car has Comfort and Comfort+ modes for its air suspension as well as the usual Normal and Sport settings and probably feels most at home in Comfort.
Thus configured, it glides along very smoothly and with excellent long-wave compliance at typical motorway and A-road speeds, but never quite oscillating on its springs or running out of close body control as readily as it can at higher speeds in Comfort+.
BMW’s Adaptive mode ought to be the car’s most effective setting but, as more than one tester noted, it allows the secondary ride to become just a little bit fidgety and excitable.
In Sport mode, the air suspension lowers the body by 10mm, stiffens the chassis rates and loads up the Servotronic power steering but, although it does all of that discreetly enough that the transformation doesn’t seem incongruous and it ultimately makes the 6 Series handle well enough to feel like a modern BMW, the net result doesn’t suit the 6 Series GT’s various strengths nearly as well as Comfort mode does.
So, more often than not, Comfort is what you settle for, delivered not at all costs but against a sufficiently high background level of handling composure that the car feels comfortable at both a 50mph pootle and a fairly brisk country road clip.
The 6 Series GT’s ride-and-handling compromise is sufficiently cleverly struck as to make the car handle like a relatively well-balanced, naturally controlled, authentic-feeling BMW up to fairly high road speeds.
On track, though, its body control and grip levels begin to betray its weight and fairly high centre of gravity. That’s entirely as you’d expect, though.