14 BMWcar
FIRST DRIVE
direct diesel injection with modern, piezo
injectors that inject the fuel at pressures
of over 2,500 bar at times. But, where
the xDrive30d uses a single, variable
inlet geometry turbocharger, the M50d’s
engine has two low-pressure turbochargers
and two high-pressure units. The latter
additionally feature variable inlet geometry
to widen their ideal range of operation.
TORQUE APLENTY
By default, the two, low-pressure units and
one of the high-pressure turbos are active,
and BMW says that there’s already 332lb
ft of torque on tap at just 1,000rpm. Once
the engine speeds up above 2,500rpm,
though, the second high-pressure turbo
comes on stream and, if you floor the
accelerator pedal, even from a standstill,
the low-pressure turbos are bypassed
altogether to allow the use of maximum
boost as quickly as possible. So what does
all this feel like on the move? In short,
ridiculously fast!
Leave the car in Comfort mode and use
the accelerator ‘softly’, and the M50d
makes decent and smooth progress, easily
keeping up with fast-moving traffic without
having to trouble the top three-quarters
of the rev counter. Even so, this engine
is louder than that in the xDrive30d,
probably because of the standard-fit
sports exhaust system. Response to
throttle inputs isn’t perhaps as crisp as
some would expect from a car bearing
the M badge, as it seems the multi-stage
turbocharging system takes a fraction of
a second to decide what set-up to go
with, before you feel any meaningful
acceleration. Still, it’ll never be called ‘slow’.
Switch into one of the Sport modes,
the sport exhaust clears its throat and you
are in no doubt you’re in the M50d, as it
bellows like a strong and angry mythical
beast chasing its prey. Some will call it
loud and uncouth (and they should stick
with the smoother and quieter xDrive30d),
while others will love the character and
personality that shine through. This is a
serious performance engine for those who
just so happen to need the parsimony
of diesel on a daily basis. In the Sport
settings, response to throttle inputs is
much sharper and forward motion is
notably more instantaneous.
One flat-out standing start will be
enough to convince you that BMW’s
official acceleration figures are realisticand achievable by mere mortals at the
wheel, and the way the M50d continues
to forcefully accelerate forward well
into three-digit speeds will shock the
uninitiated. Even so, there’s the sensation
of turbo lag at times, but perhaps that’s
exacerbated by the longer final drive
ratio the M50d gets in comparison to the
xDrive30d model.EIGHT-SPEED REVISIONS
Otherwise, they share the same eight-
speed Steptronic automatic transmission,
which has proven to be a gem in many a
BMW. It came in for a round of revisions in
time for the launch of the G05, focusing on
efficiency and refinement improvements
thanks, in the main, to a wider spread of
gear ratios and new control electronics,
along with new torsion dampers.
BMW claims that it offers smoother
changes on the one hand, along with
sportier shifts when it’s in one of its Sport
modes. I can’t disagree with any of that,
although to really enjoy a twisty mountain
road, I found myself taking manual
control of the gearchange timings – it
was the only way to make full use of the
considerable torque on tap on the exitThe M50d is certainly no
shrinking violet. There’s
a simply massive ‘M50d’
badge on the back, and
the performance and
sound to back it up.