By Bryce Baird - Isuzu

Clockwise from top:
The cockpit layout is
comfortable and easy to
use, with plenty of nooks
and crannies for odds
and sods; easy access is
available to service fulids;
it’s still a three pedal
truck, but that clutch
pedal doesn’t get much
use; the display console is
easy to read, and simple
to keep clean.
as durable. Given that it is basically the same
unit as in the 530, and is capable of handling
2500Nm, we predict durability issues won’t be
an issue.
This particular truck is equipped with a
retarder, an Isuzu magnetic driveline unit which
produces 630Nm of holdback, but it is unclear
if this is to be a standard fitting or an option.
There is an exhaust brake, of which we can only
say it is no Jacobs, but with the retarder, this
combination does a great job of keeping the
brake linings cool.
“There is a drive in Japan to get their trucks
more economical,” says Keogh. “This is the most
European or American-feeling engine so far for
us.” Despite having only 6,000km on the clock,
and being driven by a large number of people
with differing driving styles, the EXY400 had
returned 2.1km/l so far – a surprising figure
considering that distance included a Hastings-
Taupo trip loaded to 44-tonne in front of a
B-train. The engine is spinning at just 1620rpm
at 90km/h, which has to help the fuel figures
as well.
Isuzu New Zealand wanted to give the truck a
good try out to see what it can do, and although
the truck proved it could do the 44-tonne hard
trips, they see the EXY530 as being the best for
that sort of work.
The EXY400 is more comfortable revving in
the low teens on the tacho where it develops
its torque, rather than in the high teens where
Japanese trucks used to rely on whatever power
they had to get by.
It is a world apart from the old Isuzus we’ve
driven, but while the engine performance is
more akin to a Euro than a Japper, they still
have a way to go before feeling like there’s
an American or European engine under the
floorboards. After all, even the bigger-lunged
EXY530 develops only 2,273Nm (1,676lb/ft).
That, while getting closer to the American
engine torque benchmarks, won’t give an ISX
Cummins sleepless nights.
We took a trip through Auckland to Warkworth
while pulling a three-axle trailer loaded to its
39-tonne stickers. It performed well, but it
noticed the hills, as you’d expect. After all, 400
horsepower is 400 horsepower, but the engine
did seem more willing than we predicted from
the spec sheet, and it is a hard haul up this
stretch of the north.
While the transmission seemed to perform better
than the previous Isuzus we’ve been in, we
wouldn’t be surprised if many experienced drivers
operate it in manual for much of the time on
the open road. It can be slotted into auto mode
and left there, but most drivers would probably
be wanting to curb the truck’s tendency to make
unnecessary changes, particularly when cresting
hills. This happens on every automated transmission,
to a greater or lesser degree, and we suspect
the modest power-outputs coupled with 16-cogs
make the EXY400 want to hunt a little. It’s not
as intuitive as you might expect, and if the truck
ever needed to grab a big handful of gears in one
hit, say drop five or more, it will take its time figuring
out what to do and most likely the driver
will need to take over.
Under normal driving, the transmission is
more than up to the job, and as we said, a driver
could leave it in auto all day on most routes with
no problems. It does long steady grades well,
but on tricky routes like the Arthur’s Pass, you’d
need to keep an eye on it.
It’s a no-frills package: there is no hill-start,
the button on the top of the gearstick gives you
the manual/auto function, and a switch above
your head gives power or economy modes.
As Kelly points out, “It’s an aid to drive the
truck.” Almost anybody could jump in and drive
it, he says, and he’d be right. It is like driving a
big Japanese car.
Like anything, it has its idiosyncrasies, and
we’re not sure what to make of the emergency
shift box on the floor. This facility gives the driver
the option of fifth and eighth gears, as well as
reverse, as emergency options to get home or off
the road in case of transmission problems. We
seldom hear of automated transmissions giving
enough problems to warrant its inclusion, but
it’s good peace of mind.
The transmission is a three-pedal system,
which makes yard maneourvering, backing and
other precision driving easy to manage and old
school. However, most automated trucks these
days are headed to two pedals, but it costs more.
Even though it is only used for yard work, it’s
a nice light clutch that offers excellent engagement
feel. There’s little room around the clutch
pedal for the big-footed amongst us, but that’s
nothing new.
The face-lift has seen changes in the grille,
bumper and sun visor, but step inside and you’d
think you were in the 530. There’s plenty of
interchangeability between the two models, and
it seems that Isuzu have got the best of both
worlds with this tractor. It has a great cab, with
plenty of nooks and crannies to hold the modern
truck driver’s daily paper storm, and it’s a large,
light cab with excellent visibility.
As you would expect, 530 pilots get a few
nicer touches such as imitation woodgrain trim,
a six-stack CD player and a hi-roof cab, but
apart from that, the cabs are near-enough to
identical from the driver’s seat. The driver gets
an airbag and Isringhausen 6860 seat (the same
as the 530), a hot/cold storage box, a couple of
overhead lockers and a CD player in the 400. It’s
a pleasant place to spend the day.
Flipping the air-sprung cab is easy, as there’s
an electric motor to do the hard work, as is typical
with a Japanese truck. Once the cab is up,
stand back and marvel at the plumbing. There’s
plenty, a result of the increased amount of EGR
technology bolted to this engine to achieve Euro
4 compliance.
Oil changes are 20,000km apart, and the dipstick
and oil filler hide behind the grille. We were
struck by the tidy cable bundling when we had a
peak at the undergrille layout – it’s quite arty.
Isuzu have managed to price the tractor well
by mixing new technology with the tried and
proven. Braking is undertaken by EBS-compliant
drum brakes – a cost-efficient alternative
to discs – but this EXY is fitted with eight-bag
air-suspension. The bags can be controlled with
a remote controller to raise or lower the suspension
height for loading or coupling and, with the
front parabolic four-leaf suspension, the ride was
quite acceptable, with little body roll. It is on the
stiffer side of the equation and is nicely ironed
out by the driver’s sprung seating.
As we’ve come to expect from Isuzu, the
in-cab noise was down to European levels and
apart from a bit of wind buffing from the mir-
Left top: The get-home box
– an emergency option
should the transmission
strand the vehicle. It’s great
to see it, but we doubt it’ll
ever get much use; it’s an
Isuzu, all said and done.
Middle: Switchery is
minimal, but the truck has
a cross-lock and plenty
of blanks should extra
features be wired in.
Below: New bold styling is
still distinctly Isuzu.
24 NZ Trucking September 2010 September 2010 NZ Trucking 25