28 AUTOCAR.CO.UK 3 1 JULY 2019
Δ question, it’s effective. The A45 is
a bit brittle at low speeds but settles
as you get faster, combining good
straight-line stability with terrific
mid-corner agility and response
given that, at 1625kg, it’s relatively
heavy for a 4.4m car. The electronics
can tweak an inside rear brake on
the way into a corner to help turn-in,
and as soon as you get on the power it
pushes power to the outside rear for a
r e a l l y p o sit i v e r ot at ion – no ne e d for
anything like active rear steer here or,
a s m i g ht b e ne e de d i n s ome c a r s , t o
g i v e it a bu n g a nd l i f t of f. It fe e l s v e r y
positive but quite natural.
Extend the A45 on a track and
there’s little understeer, and the rear
wheel engagement means you can
get on the power early. It’s extremely
effective and more involving and
adjustable than an Audi RS3. More
like a Ford Focus RS, unsurprisingly.
The steering’s weight change
between modes is pretty subtle. In
any it’s medium-weighted, extremely
precise and pleasingly responsive. I
rather liked it, although in its heavier
setting, when there’s lots of torque
going rearwards, it felt less inclined
to self-centre, so you have to windthe lock off yourself, unnaturally.
So off you go to press some buttons
and find a better mode, by which
t i me t he n ic e bit of r oa d y ou’r e on h a s
pr oba bl y e nde d , w h ic h i s a sh a me.
And then there’s the party piece:
genuine AMG levels of shove
from a 2.0-litre four-pot. But just
as remarkable as the outright
s p e e d , p e rh ap s e v e n mor e s o i s t he
way it goes about it. Most heavily
turbocharged petrols engines make
you wait while the turbo spools
before delivering their big slug of
torque from low revs. Not so here.
`
The rear wheel
engagement means
you can get on
the power early
a
@matty_prior
Price £50,000 (est)
Engine 4 cyls in line, 1991cc,
turbocharged, petrol
Power 4 1 6 b h p a t 67 5 0 r p m
Torque 3 69 l b f t a t 5 0 0 0 - 5 2 5 0 r p m
Gearbox 8-spd dual-clutch auto
Kerb weight 1 6 2 5 kg
Top speed 168mph (limited)
0-62mph 3 .9 s e c
Fuel economy 33.6mpg
CO 2 , tax band 192g/km, 37%
RIVALS Audi RS3, BMW M2
Competition
MERCEDES-AMG A45 S
Complicated inside and underneath,
the absurdly powerful A45 S hot
hatch is uniquely capableAAAAC
It’s involving and adjustable on track and the turbocharged engine is pleasingly short on lag
HEAT MANAGEMENT
THE A 45 WAY
The previous A45’s engine had its
turbocharger in front of the engine,
but here it’s behind it, towards the
bulkhead, which apparently allows
ancillaries to fit more easily below
a flatter bonnet, lets the exhaust
route out more efficiently and
means air has a cleaner through-
flow from the front.
It also means, presumably,
that the turbo is in a hotter place,
which is suboptimal, but AMG haspractice at sorting this because
the turbos on its V8s sit within the
engine’s ‘V’, where things tend to
get pretty warm.
So the A45’s roller-bearinged,
twin-scroll turbo has water and oil
cooling, plus air ducted over the
top of it, while intake air passes
through a two-stage intercooler,
p a r t of w h i ch i s h o o ke d u p to th e
air-conditioning circuit. Heat
management elsewhere means
that, as well as a belt-driven water
pump working flat out to keep
the head cool, there’s a separate
electric pump for the crankcase
that only works part of the time,
independently allowing that to run
hotter and more efficiently.
I think boost pressure is limited
at lower revs so the engine feels
more naturally aspirated; there’s
genuine shove from around 2500rpm
but peak torque doesn’t arrive
until 5000rpm and peak power at6750rpm, near the 7000rpm limit.
It’s very smooth and very linear
and very fast. Depending on the
drive mode and exhaust setting (the
combination sometimes involves the
speakers, too), you might get a muted
thrum, a Renault Sport Mégane-like
exhaust-and-turbo-rush or a mildly
cross growl. The ‘whoosh’ felt most
appropriate. The eight-speed dual-
clutch auto is the best I’ve felt in a
Mercedes, fairly zinging through
both up and downshifts, and only
rarely, on circuit, delaying when you
ask for shifts at high revs.
It all makes for a car that feels
l i k e it h a s mor e i n c om mon w it h a
There’s a bewildering array of driving modes and optional settings; five-door bodystyle adds practicality
Nissan GT-R than most other normal
hot hatchbacks. Not perfect and
sometimes annoying, and although a
BMW M2 is more two-dimensional,
I’d prefer the straightforward rear-
driven response of the M car and less
baff lement. But if that doesn’t have
enough doors or fails to f loat your
boat, then nothing else combines the
qualities of the A45.
MATT PRIOR