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By
EWAN KENNEDY
11 February 2008
The relentless push by BMW Australia into the turbo-diesel market
continues. This time with the introduction of a clever twin-turbo
turbo-diesel powerplant that produces the sort of power and torque
about which engineers could only dream a few years ago.
Indeed, few petrol engines had the outputs produced by this new
diesel from BMW. And those huge V8 petrol engines which could
match the numbers had fuel consumption and emissions levels that
would be considered antisocial by today’s standards.
This new 3.0-litre BMW powerplant churns out a big 200
kilowatts, and a healthy top-torque figure of 565 Nm. The latter
developed at only 2000 rpm, with good torque available throughout
virtually the complete rev range.
The secret to the big spread of torque is the use of two
turbochargers operating in series with one another. A small,
lightweight turbo spins up quickly to make extra torque from as
little as 1000 rpm; a larger, more powerful turbo joins the action
at about 1500 rpm. The two turbos work in conjunction from there
until 3200 rpm, with the larger unit doing more and more of the
work as the revs reach that number. At 3200 the small turbo cuts
out completely, leaving the big one to work on its own.
Our initial 250-kilometre test drive at the time of the launch
of the new twin-turbo engine was done over country roads, many of
them in hilly country, in Victoria. The engine had a minimum of
lag when first accelerated, a solid surge of torque at 2500 rpm
and ran sweetly all the way to 4700 rpm, a big number for a diesel
engine, if asked to do so.
There's something about the feeling of any straight-six engine
that’s quite special and this BMW unit, like many other similar
sixes in the past, is something really pleasant to sit behind.
However, we will have to test drive the car in traffic
conditions, particularly in our well-travelled home area, to
comment fully on how it feels in day-to-day conditions.
Particularly those that involve accelerating from low speeds over
extended periods of boring commuting.
BMW in Europe has measured the fuel consumption of the new
twin-turbo diesel at 8.8 litres per hundred kilometres in the
combined EU cycle. Expect a similar result when tested to
Australian Standard tests. On our drive program we managed an
overall figure that was considerably higher at 11.4 litres per
hundred. Admittedly there was some reasonably hard driving during
and there were plenty of hills to climb. But we had expected lower
consumption than we achieved. Perhaps the laboratory test favoured
the twin-turbo setup? We will measure the diesel consumption
during our extended test period in a few weeks time.
Our testing was done in vehicles with standard suspension, as
well as in a couple fitted with the self-levelling ‘air’
suspension system, a $2000 option. The car was noticeably more
comfortable on poor quality roads with the self-levelling
suspension, yet retained the sharp steering feel so beloved by
Australian BMW enthusiasts, so may be the system of choice for
those who like their BMWs to have the best sporting setup.
There are no appearance changes in this latest BMW X5, either
inside or out. Which is what you would expect in a vehicle that
has only been sold in Australia since late-2000. This lack of
styling alterations also reflects the confidence of the Bavarian
car maker in its already successful product.
The new BMW X5 3.0sd comes 18-inch alloy wheels, a navigation
system, television and a rear-view camera amongst many other
features. It has a recommended retail price of $102,800; to which
on-road costs have to be added.
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Marque Publishing Company
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