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