Car test
R0027A
See also R9612 and R9959
May 2000
TEST
UPDATE
VW 3-cylinder diesels
Featuring Polo 1.4 TDi and Lupo 3L
HIS ISN’T THE FIRST THREE-CYLINDER
diesel in modern times – Daihatsu had one under
the bonnet of the Charade in the early eighties.
T
However, this state-of-the-art VW diesel has come to
fruition as part ofaproject to demonstrate how frugal and
environmentally considerate future motoring can be.
In 1.2 litre/61bhp guise, installed in a special version
of the Lupo(not yet on sale here inthe UK), VWclaims
that its fuel consumption will average 3 litres per
100km (i.e. 94½ mpg) in the official tests – hence the
title Lupo 3L(itre).
To achieve such frugality, VW has virtually
reconstructed the model, so that although it looks similar
to any other Lupo, in fact it bristles with ingenious (and
expensive) solutions to reduce weight and ensure
ultimate mechanical efficiency. The use of aluminium,
plastics, even magnesium in the body and chassis has
produced a formidable weight saving, compared with an
equivalent, regular-series Lupo 1.7SDi, and its
aerodynamic efficiency has improved from a Cd value of
.32 to .29.
However, it’s the under-bonnet wizardry that plays a
major role. As well as the direct-injection three-pot
turbo-diesel, the “conventional” five-speed
synchromesh gearbox is also electronically controlled, it
uses hydraulics to do the shifting, so it finishes up
behaving like an automatic, with an additional
“Tiptronic” manual shift facility when required.
Even the automatic shift sequence has dual modes –
for ultimate fuel economy, an Eco button on the facia is
depressed, which results in very early upshifts
(1800rpm on half-throttle compared with 2800rpm in
non-Eco mode), plus two other features. These are a
freewheel on the overrun (like being in neutral) and the
engine switching off a few seconds after coming to a
traffic halt – if the footbrake stays depressed. The
traffic-lights turn green, you release the brake and the
engine starts again, with gentle “creep” (just like a
conventional automatic) in gear.
We found the early upshifts embarrassing at times
(when it changed from first to second half way across
the traffic, emerging from a junction, for instance) and
the shift quality can be rather ponderous, especially
when taking off from rest.
In non-Eco automatic guise, these “special effects”
don’t occur and if you prefer a clutchless manual car,
Continued on page 3
PERFORMANCE - 1.4 TDi
2
PERFORMANCE - 3L
Acceleration time in seconds
mph
THROUGH
THE
GEARS
IN 5TH
GEAR
IN 4TH
GEAR
20 mph
5TH/4TH
SPEED
RANGES
30
30
2.0
7.8
4.0
40
40
50
4.9
13.3
7.2
50
17.6/10.2 10.0/6.8
13.3/7.2
60
8.4
17.8
10.8
60
Maximum speeds using accelerator kickdown
3
1
REVS
PER
MINUTE
1st
2nd
3rd
* for best acceleration
4200*
4200*
5th4th
4100
25½
43½
24
64
87
13.3
22.8
15.4
9.5/8.2
5
108
mph
Acceleration time in seconds - using kick-down or manual
70
70
mph
THROUGH
THE
GEARS
20 mph
SPEED
RANGES
USING
KICKDOWN
30 40 50 60 70
2.0
6.0
9.6
30 40 50 60 70
4.0
7.6
4.0 9.8
Maximum speeds
using accelerator kickdown or manual
5
REVS
PER
MINUTE
4th
1st/2nd
3rd
4400 4175 3975 3475
5th
4
33
2
1
103
93
67
42
24
15.8
mph
FUEL CONSUMPTION - 1.4TDi
Type of use - with air conditioning off* mpg
Urban (17mph average/heavy traffic) 39½
Suburban (27mph average/6.4 miles from cold start) 55
Motorway (70mph cruising) 55½
Cross-country (brisk driving/20 miles from cold start) 64½
Rural (gentle driving/20 miles from cold start) 76
Typical mpg overall 62
Realistic tank range (not nominal tank capacity) 37 litres/500 miles
*with air conditioning switched on, consumption will increase by 2–4% in
winter and 4–8% in summer
FOR THE TECHNICAL - Polo 1.4TDi
ENGINE
Type transverse three cylinder
with all-alloy block and head. Four
main bearings and counterbalance shaft
Size 79.5 x 95.5mm = 1422cc
Power 75bhp at 4000rpm
Torque 144 lb ft at 2200rpm
Valves belt-driven single
overhead camshaft actuating two
valves per cylinder
Fuel/ignition direct injection
diesel with electronically
controlled high pressure unit
injection for each cylinder;
turbocharger and intercooler with
unregulated catalyser. 45-litre
tank, with low-level warning lamp
TRANSMISSION
Type five-speed manual,
front-wheel drive
Mph per 1000rpm 26.4 in 5th;
20.7 in 4th
CHASSIS
Suspension front: independent
damper/struts with integral coil
springs and lower wishbones.
Rear: torsion beam (dead) axle
with trailing arms and coil springs;
telescopic dampers. (Modified
front wishbone and wider track in
latest Polos)
Steering rack and pinion with
hydraulic power assistance; 2.9
turns between full locks. Turning
circle diameter averages 10.1m
between kerbs, with 14.6m circle
for one turn of the wheel
Wheels 6J alloy with
185/55R14H tyres (Michelin
Energy on test car)
Brakes ventilated discs front,
drums rear with servo-assistance
and standard anti-lock control
(ABS)
FUEL CONSUMPTION - 3L
Type of use - Eco mode switched on/switched off mpg
Urban (17mph average/heavy traffic) 49 / 48
Suburban (27mph average/6.4 miles from cold start) 60 / 59
Motorway (70mph cruising) 66 / 66
Cross-country (brisk driving/20 miles from cold start) 72 / 73
Rural (gentle driving/20 miles from cold start) 90 / 86
Typical mpg overall 71½
Realistic tank range (not nominal tank capacity) 28 litres/440 miles
*with air conditioning switched on, consumption will increase by 2–4% in
winter and 4–8% in summer
MEASUREMENTS
Centimetres
(with sunroof)
142
T: typical back seat space behind medium-sized front occupants
183*
163
81-108
42-45 51
11
(inner sill)
374
124
No
* 168 with mirrors folded
kerb weight : 1016kg (maker’s figure)
Polo Five-door hatchback
93-98
T
93
T
33
(outer sill)
91
66
123
60
117
47-62
91
89-110
173
29
68
3
moving the selector across the gate produces sequential
shifts, up and down, as the stick is nudged fore and aft.
That’s unless your selection is unreasonable, in which
case you’ll be ignored, or it will make its own choice
(e.g. selecting first as you pull up, even if you didn’t
remember to). You sometimes finish up wondering
which gear you’re in.
The electric power steering (another fuel-saving
measure) can weight-up in brisker cornering, when
pronounced roll and lack of tyre grip also begin to show;
this Lupo really doesn’t like being pressed, though the
ride is reasonable.
The Polo alternative
As we write, VW has still to decide whether this Lupo will
be converted to right hand-drive and brought to UK
showrooms. In any event, it’s hardly likely to make a profit
– it really is costly to build and is a bit of a flag-waving
exercise even back home, with politics involved.
However, the latest revised Polo has recently been
augmented by a 1.4/75bhp version of this special
engine, but without the drastic weight-saving
measures or the transmission complexities. The result
is a still-expensive (but larger, five-door) proposition
that weighs 186kg more, has an extra 14bhp, but has
an mpg CombinedOfficial test result that’s 33 per cent
worse than the Lupo 3L – or that’s how it seems.
100mpg - Fact or Fiction?
The AA has always made a point of conducting its own
real-life mpg tests, using specialtest routes and metering
equipment. This results in accuracy and repeatability to
within 1mpg – vital when comparing the counter-claims
of rivals. In this instance, of course, they’re from the
same manufacturer, but VW was as keen as we were to
see our results. For the test, we borrowed a left-hand
drive Lupo 3L specially brought-in from Germany.
Our tables speak for themselves. The trouble is that
the actual 10mpg gain we recorded in overall terms in
the Lupo’s favour mayseem a let-down, comparedwith
the publicity hype. Yet in engineering development
terms (where gains are always more modest than in the
sales department), any fully equipped four-seater
hatchback that can accelerate this respectably and still
attain over 70mpg in typical use,has to be something of
a tour de force. Remember, this Lupo comes equipped
with all the safety equipment and low pollution
measures demanded nowadays; car makers have been
struggling in recent years to maintain diesel economy
in the face of latest legislation.
In fact, the Lupo can attain as much as 90mpg away
from traffic. However, you must be prepared to
bridle yourself to under 2000rpm, no more than
45mph and be happy to live with the Lupo’s Eco
mode switched on.
Testers’ choice
For ourselves, we would settle for the Polo; it really is
an endearing performer. Forget the economy aspect
for a minute and you’re left with a sweet power unit
that combines vibration-free response with eager
pull-away from lower revs than you would think
sensible. The contra-rotating balancer shaft
effectively quells most of those nasty vibes that afflict
so many diesels around 1500rpm – including VW’s
four-cylinder derv-burner.
This brings us back to the problems of how and when
to change gear. The Lupo’s auto-solution doesn’t
work too well, and we suspect that, left to their own
devices, most Polo TDi drivers will spend too much
time in the lower ratios.
We found it paid off to operate between 1200 and
1800rpm when accelerating normally. VW should
install a change-upadvisory light (like that used onthe
Formel E models in the early eighties) to encourage
drivers to do the right thing.
Our track testing confirmed that revving this
only-too-willing engine is largely pointless – it goes
almost as well in fourth when overtaking!
This reinforces the fact that, unlike many small
diesels, this Polo gives you the choice of remarkable
mpg or eageracceleration – butyou can’t enjoy both at
the same time, of course.
VERDICT
The Lupo 3L is a valiant enterprise and the car isn’t
without appeal to environmentalists or those who are
simply worried by escalating fuel costs. However, the Polo
1.4TDi, compromise though it may be, looks the better
proposition, even though its asking price is too high.
Of course, it’s the engine rather than the host car
that’s the main attraction – married to the Fabia, it
would look irresistible.
REVISED POLO FOR 2000
hile the next all-new Polo is having its audition (at
W
lower ticket prices) as the Skoda Fabia, both the
Polo and Seat Ibiza havebeen freshenedup in appearance
and equipment in an attempt to remaincompetitive for the
next couple of years.
The Polo in this latest guise is a shade longer outside,
though not to the enhancement of interior space, which is
restricted in the rear; only headroom shows any
improvement. The Lupo-style facia isn’t without its
irritations (poor ventilator direction control, hard-to-see
minor controls and dials), but both interior finish and
safety equipment are impressive, with standard ABS and
dual airbags on even the cheapest version.
Apart from this 1.4TDi, engines aren’t particularly
refined – we found the racey GTi’s acceptably raucous,
the all-alloy 1.4 16v’s unacceptably gruff at times, with a
surprisingly ruffled ride, as well.
4
HOW THE POLO
1.4TDi COMPARES
VW POLO 1.4 TDi 3/1422/75 2650 13.3 22.8/15.4 62 26/26† 108 93/66 2.9/10.1 374
Fiat Punto 1.9 JTD 4/1910/80 2330 14.2 25.4/17.1 51½ 27/12 108 96/67 2.8/10.9 384
Peugeot 206 Dturbo 4/1997/90 2600 11.4 19.8/14.4 52½ 26½/8 108 94/66 3.3/10.1 384
Seat Ibiza 1.9 TDi* 4/1896/90 2400 11.3 21.7/15.1 57 28/32 109 97/72 3.1/10.1 385
Vauxhall Astra 1.7 DTi 4/1686/75 2675 14.0 32.3/20.5 56½ 26/21 108 99/75 3.1/10.4 411
VW Lupo 1.7SDi 4/1760/60 2700 18.3 36.5/26.0 62 26½/18 104 92/65 2.9/9.9 353
* 1998 model † with ABS
Engine
cyl/cap/power
(no/cc/bhp)
Revs at
70mph
(rpm)
30-70mph
through
gears (sec)
30-70mph
in 5th/4th
gears (sec)
Fuel
economy
(mpg)
Brakes
best stop
(m/kg)
Maximum
legroom front (cm)
Typical leg/
kneeroom rear (cm)
Steering
turns/
circle
Overall
length
(cm)
© The Automobile Association 2000
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