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By EWAN
KENNEDY
24 August 2009
Like
all thinking car marques BMW is working hard at lowering emissions
and fuel consumption. Unlike others, it has been doing so for
decades, thus giving it a head start in today’s enlightened
world.
But BMW has made a determined decision that low emissions should
not get in the way of performance and, even more importantly,
driving enjoyment. It learnt this lesson to its corporate
embarrassment back in the mid 1980s when it introduced a special
economy petrol engine which concentrated on providing high torque
– but not much else. While these ‘eta’ engines did trim
something off their fuel usage they were terrible things to drive.
Would you believe a redline at 4600 rpm – in a six-cylinder
petrol BMW?
Anyhow, the lesson has been learned and BMW vows that never again
will driving pleasure be dulled simply to make an engine clean.
The result is cars like the BMW 120d six-speed manual in which we
have just enjoyed an enthralling day of competitive driving. The
brief was simple, drive from BMW's Melbourne head office to Philip
Island raceway and back. The road sections of the trip were to be
done at normal speeds, but with an emphasis on economy driving.
While at the track we would undertake several high-performance
tests.
The BMW 120d has an official fuel consumption rating of just 4.8
litres per hundred kilometres. With 130 kW of power and 350 Nm of
torque it leans towards the performance end of the scale, but that
fuel consumption is impressively low.
As one of the competing motoring journalists, and an economy
driver of many years standing (with multiple entries in the
Guinness Book of Records) I decided to push for minimum fuel use
on the trip to the track and to drive back in the way most
thinking drivers would. That is with economy in mind, but not
taking precedence over all else.
Our drive to Philip Island wasn’t done straight down the
freeway, but rather on a detour through the sort of interesting
roads that appeal to keen drivers. I managed to get the
consumption down to just 4.0 litres per hundred, an irritating
figure as I had had it sitting at 3.9 litres for quite a while
until I managed to get lost and had to do some U-turns and
backtracking. Oh, well!
By the way, 4.0 litres per hundred kilometres is an amazing 71
miles per gallon in the old money.
There's more to the BMW's low fuel diesel consumption than simply
advanced technology. It also has a stop-start feature that turns
the engine off when the car comes to a standstill and you
disengage the clutch. The engine is then using no fuel and
producing no pollution. It restarts as soon as you push the clutch
pedal down again. You can hear it starting, but it's smooth and
after the first few times I found myself barely aware that it was
happening.
The most important economy feature of all is an indication on the
dashboard of when you should change up and down gears. Most
drivers of manuals, indeed virtually all of us, tend to hold onto
lower gears far longer than is necessary, and thus use unnecessary
fuel. BMW says this simple feature can give a bigger saving in
fuel than any other of the new technologies it has added to the
car.
Philip Island in a BMW is always a fun experience and we were able
to fang the cars hard and fast through a couple of disciplines, a
slalom and a motorkhana. The little 120d is a neat vehicle for
this sort of driving, being compact and light and therefore very
responsive to the steering and throttle inputs. We didn’t
measure fuel consumption during this testing, deliberately so
because the whole idea of these exercises was to forget economy
and instead appreciate the car to its full potential.
As mentioned, on the way back I drove the BMW 120d in a normal
manner. It used 4.6 litres per hundred kilometres, about 15 per
cent more than on the full-on economy push on the way down. Its
average speed was almost 10 per cent higher. But driving in this
normal way isn't as hard on the body or mind, so it's probably the
way we advise you use the car.
© Copyright
Marque Publishing Company
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