Emission Tests on a Vespa
125 cc Primavera Scooter
November 1975
Thomas Cackette
Standards Development and Support Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Environmental Protection Agency
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BACKGROUND
In the fall of 1975 EPA contacted a local Vespa motorcycle dealer
with the intention of leasing a Vespa for testing purposes. The Vespa
scooter models were of interest to EPA because of their unique body
design (and thus possibly different road load characteristics), and
because of recent advertised claims of 'exhaust pollutants almost
entirely eliminated1 (Ref. 1 and 2). As a result of our inquiry,
the local dealer contacted the distributor and a 1974 Vespa 125
Primavera was made available to EPA for testing.
The Environmental Protection Agency receives information about
many systems which appear to offer potential for emission reduction
or fuel economy improvement compared to conventional engines and
vehicles. EPA's Emission Control Technology Division is interested
in evaluating all such systems, because of the obvious benefits
to the nation from identification of systems that can reduce emissions,
improve economy, on both. Tests are performed at the EPA Emissions
Laboratory in Ann Arbor, Michigan, and the results of all such tests
are set forth in a series of reports.
The conclusions from the EPA evaluation tests can be considered
to be quantitatively valid only for the specific test vehicle used,
however, it is reasonable to extrapolate the results from the EPA
test to other types of vehicles in a directional or qualitative manner,
i.e., to suggest that similar results are likely to be achieved on
other types of vehicles.
VEHICLE DESCRIPTION
The motorcycle tested was a 1974 Vespa 125 Primavera scooter with
195 miles on the odometer. The engine is a single horizontal cylinder,
two stroke, carbureted engine of 121.17cc displacement. A tag on the
vehicle certifies the power does not exceed 5 brake horsepower (no
specific power is specified.)
The motorcycle was inspected and tuned by a Vespa factory representative
prior to delivery to EPA.
TEST PROCEDURE
The test procedure for this motorcycle consisted of coast down
tests to determine road load horsepower, followed by emission tests.
The Vespa was taken to the Transportation Research Center of Ohio
(TRC) for coast down tests. In a coast down test, the vehicle is accelerated
to a constant speed, the clutch is disengaged, and the vehicle is allowed
to coast with the road, vehicle, and aerodynamic forces slowing the
vehicle.Ten coast downs, five in each direction, were performed. The
velocity was measured by a radar unit and was recorded on magnetic tape
along with the time and wind history. The data were processed using
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a least squares curve fitting method which yielded a composite equation
for the road load force.
' The road load power determined from the coast down tests is shown
in Figure 1. Also shown in this figure is the dynamometer power
absorption curve which results from using the road load power value
specified in the NPRM (Reference 3) for the Vespa's inertia category
(2.53 kw at 65 kph for a 160 kg equivalent inertial mass). The
curves show that the Vespa has a slightly'lower road load power require-
ment in the 40-60 kph range than a 'standard1 160 kg equivalent inertial
mass motorcycle.
For the Vespa emissions tests, a lower total absorbed power than
specified in the NPRM was used. The lower absorbed power is based on
the actual road power determined from the coast down tests. The
normal procedure is to set the dynamometer power at 65 kph, however
for the Vespa the power was set at 50 kph. The top speed of the Vespa,
as determined at TRC, is 76 kph. Limited by the top speed, the coast
downs occurred over a usable range of 65 to 25 kph. To avoid extra-
polation of the coast down results, the road power at 50 kph was
determined and this value, minus the dynamometer friction was set
on the dynamometer power absorber. A summary of the road load powers
is presented in Table I.
TABLE*!
Road Load Power at 50 kph
As specified in NPRM 1.25
As determined from coast downs 1.15 kw
Power used for dyno tests 1.15 kw
Figure 2 presents a comparison of the road load power of the motorcycle
and the power absorbed by the dynamometer. The absorbed power in
both cases is 1.15 kw at 50 kph. The comparison shows that the
dynamometer absorbed power is slightly less at most velocities than
the road load power determined from the coast downs.
(1) Determined from Figure 1. The NPRM specified 2.53 kw at
65 kph.
TEST RESULTS AND CONCLUSIONS
Two tests accomplished per the NPRM procedures were performed. Test
conditions were 1.15 kw total absorbed power at 50 kph with 160 kg inertia.
The modified driving cycle for motorcycles with displacements less than
170 cc was used. The motorcycle was capable of following all portions of
the driving cycle. The average mass emissions are presented in Table II
along with the proposed interim and final motorcycle emission standards.
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-------
TABLE II
Mass Emissions - Vespa 125
(Grams per kilometer)
Test # 2605
Test # 2619
Average
HC
4.71
4.82
4.77
CO
13.3
12.3
12.8
NO*
.04
.03
.03
Economy, Km/1
33
34
34
1978 Standard 5.0 17 1.2
1980 Standard 0.25 2.1 0.25
The motorcycle tested meets the 1978 interim standardsbut exceeds
the 1980 standards by factors of 19 for HC and 6 for CO.
»
Table III compares the Vespa test data with similar motorcycles
and with light duty vehicles.
TABLE III
Comparisons with Other Vehicles
Vespa 125
Range for similar
1972 LDV Standard
(Grams per
motorcycles
-
Kilometer)
HC
4.8
4.6-8.5
2.1
CO
12.8
5-15
24
.03
.02-. 10
1.9
1975 LDV Standard .93 9.3 1.9
(1) Range is for other single cylinder 2 stroke motorcycles of
approximately 125 cc displacement, based on EPA and industry test
results.
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Table III indicates that the Vespa's emissions are typical of
other single cylinder two stroke engines of similar displacement.
When compared to controlled light duty vehicle standards, the Vespa emits
5 times more HC and 1.4 times more CO than the 1975 Light Duty Standard.
NOx emissions are only one sixth the standard, and fuel economy is much
better than most light duty vehicles. The claim, however, that Vespa
emissions are almost entirely eliminated is not justified when compared
to other similar motorcycles or controlled light duty vehicles.
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REFERENCES;
1. Wall Street Journal - Eastern Edition, Friday, August 15, 1975, Page 3.
2. T.V. Guide - Southeast Michigan Edition, September 6-12, 1975, Page A-49.
3. Federal Register, Vol. 40, No. 205, October 22, 1975, pages 49496-49530.
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APPENDIX I
TEST VEHICLE DESCRIPTION
1974 VESPA 125 PRIMAVERA SCOOTER
ENGINE
Type 2 cycle, horizonal single cylinder
Bore X Stroke 55 mm x 51 mm
Displacement 121.17 cc
Compression Ratio 8.2:1
Maximum Power Specified as less than 5 hp (3.7 KW)
Fuel Metering 1 barrel carburetor
Fuel Requirement Petrol with a 2 percent mixture of
2 stroke motor oil (RON not specified)
Cooling Air cooled by centrifugal fan
DRIVE TRAIN
Transmission Type 4 speed manual
Final Drive Ratio.... .*. 5.31:1
CHASSIS
Type Monocoque type of pressed steel sheet
Tire Size 3.10-10"
Tire Pressure Front 123 kPa (17~PSIG)
Rear 157 kPa (22.7 PSIG)
Weight As Tested . 162 Kg
Inertia Weight 160 Kg
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TEST * 18-2605
MFG.
CODE MOOEL
415 125 SCOOTER
1976 MSPCP CONSTANT-VOLUME SAMPLER RESULTS MOTORCYCLE
VEHICLE 1.0.
VfSPA 74 SCO
MOO.
YK
74
CC
125.0
INPUT IA CURB NO.
MASS-KG MASS-KG CYL.
160 ' 0 1
ACT. OYNO A
H.P; HP n 65 KPH C
0 3.0 0
PROCFSSEDI 1SI50IS9 OCT IS, 1975
UTL TRANS S.PAT.
AXLE N/V
RATIO RATIO
0.0 0.0
RORE
0.0
MANUFACTURE SPFCS.
STROKE c.R. TIMING RPM
' 0.0 0.0 ' 0.0 0.
IDLE/ -MANUFACTURE DATA-
« CO GEAR RPM HC CO NOX
0.0 0. 0.0 0;0 0.0
0 0
—/ TIRES
TEST TEST
YEAR TYPE
76 5
DRIVE SOURCE
FVAP SIZE RIM CYCLE CODE
To.o 2 i
REQUESTOR FUEL
INIT. BRANCH OATF .INJ. SHUT. CCARH «8BLS CARP MODEL
T C ECT 10-15-75 00
EXHAUST SYSTEM
TYPF.S . NAME
00000
EVAP EGN CRANK' FUEL FUEL
SYS; TYPE CASE' TYPE TANK MAlNT ODOM GVW
01 01 00 0 0
PF.ODESTOR COMMENTS J HP SET »T SO KPN BASED OM COAST DOWNS,=1.53VESPA 74 SCOOTF.R
LABORATORY COMMENTS * HP 01=1*61283 B2=2224551 R3=1680900
ENGINE FAMILY I
CVS HOURS I
INO. flA^O / TEMP.,OF / MANOMETER / CVS PRES. /—INITIALS—/ DYNO. CVS
TEST DATE OOOMETFR H.P. "HO DRY WFT CVS SPEC.GR. UNITS IN OUT ". OPER. DRIVER NO. UNIT
10-15-75 0. 2.4 29.90 74.0 59.0 101.0 1.75 IN 22.20 20.60 j TJC DCS HC 11C
OILUTION AIR 0.0 0.0 ] ......
CUBIC FT CALCULATED NOX IGN IDLE EVAP. LOSS TIRE '?
PER REV. RPM FACTOR TIMING RPM * co GEAR HPM GRAMS PRES. j
0.27697 1443. 0.«927 00 0. 0.0 0. i , 23.0 '-.
BAG 1 4.612 KM 12174. COIWTS
EXHAUST SAfPLF
RANGE METER cowc.
'" HC-FID 7 IP.4 579.n
CORRECTED MASS EMISSIONS \
CONCENTRATIONS GMS GMS/KM * KM/L
575.73 PPM 26.96 5.85 |
722.64 PPM 68.32 14.81. I
0.11* « 175.08 37.96 " 29.4
1.50 PPM 0.21 0.05 '
20797. COUNTS 4fl99.0 CU. FT. 1377.S SECONDS D/FACTO"=65.054 ACT HPM= 1436.1 RPM RATIO(C/A)=0.9954
-H
(
M '
RANGE
' 7
fl
. 1
4
METER
0.2
0.4
5.0
0.2
SAMPLE
CONC.
6.85
8.13
0.043
0.20
COH9CCTF.O
MASS EMISSIONS
CONCENTRATIONS GMS GMS/KM
336.17 PPM 26.»9 4.35
473.5? PPM 76.48 12.38 .
0.081 % 205.72 33.31
' 0.80 PPM 0.19 0.03
KM/L
I 35.2
2854.8 CU. FT.
507.4 SECONDS D/FACTOR=48.839 ACT KPM= 1433.1 RPM RATIO(C/A)«0.9933
KM/L
• EXHAUST SAHPU
•
HC-FIO
CO
C02
NOX CHEM
RANGE
7
a
l
4
WEIGHTED VALUES (IT
GRAMS/KM
METER
14.9
33.9
1P.O
1.8
HC
4.71
CO'iC.
47'V.J.O
71?. •?«
0.156
l.ftO
CO
13.3
BACKGROUND SAMPLE
R&NGF. METER
7 0.1
8 0.0
- r 4.9
4 0.4
C02
34.9
COMC.
3.43
0.0
0.042
0.40
MOX
0.04
CORPF.CTEt)
CONCENTRATIONS
470.74 PPM
712.68 PPM
0.114 %
1.41 PPM
MASS
GMS
21.95
67.08
169.05
. 0.19
EMISSIONS
GMS/KM
4.70
' 14.37
36.22
0.04
•
^
',
t
*
i
75
T'
.;
BEFORE ROUNDING
4.7140 13.3187 34.8793 0.03611
31.8
75 WEIGMTEDl
KM/L
33.
J33.1247
FUEL-WEIGHTl
KM/L
0.0
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TEST * 18-?619
197ft MSPCP CONSTANT-VOLUME SAMPLER RESULTS MOTORCYCLE
PROCFSSEOI 15103110 OCT 20« 1<>T5
MFG.
CODE
415
MODEL
SCOOTER
VFHTTLE 1.0.
VFSPA 74 SCO
MOO.
VR
74
OIS°L.
cr
125.0
INERTIA
MAS<=-KG
160
CURB
MASS-KG
n
wo.
CYL.
1
H.P.
n
ACT. OYNO A
HP « 65 KPH C
3.0 0
UTL TRANS S.PAT.
000
TEST TEST
YEAR TYPE
76 5
AXLE N/V MANUFACTURE SPECS.
RATIO RATIO BORE STPOKF C.R. TIMING PPM
0.0 0.0 0.0 • 0.0 0.0 0.0 0.
IOI.E/ MANUFACTURE DATA-
* CO GEAR RPM HC CO NOX
0.0 0. 0.0 0.0 0.0
-_/ TIRES DRIVE SOURCE
EVAP SIZE RIH CYCLE CODE
0.0 2 1
REQUESTOR FUFL
INIT. BRANCH DATE . INJ. SHUT. «CARR »SBLS CARR MODEL
TC . FCT 10-15-75 0"
EXHAUST SYSTEM
TYPES NAME
00000
EVAP EGN
SYSi TYPE
01
CRANK
CASE
0
FUEL
TYPE
1
FUFL
TANK
0
MAINT
0
ODOM
0
GVW
0
REQUESTOR COMMENTS J HP SFT » ^OKPH BASED ON COAST DOWNSt=l .S3HPVESPA 74 SCOOTER ; ENGINE FAMILY 1
LABORATORY COMMENTS J 01=16*0615 02=2206972 03=1659268 CVS HOURS t
IND. RAPO / TEMP.. OF /- MANOMETER / CVS PRES. •-/ INITIALS— If OYNO. CVS
TEST DATE ODOMETER H.P. »HG DRY WET CVS SPEC.GR. UNITS IN OUT : OPER. DRIVER NO. UNIT
10-16-75 196. 2.4' 2O.07 76.0 57.0 101.0 1.75 IN 22.11 20.75 j VOC JSH MC HC
DILUTION AIR 0.0 0.0 ' J • , ;
t • . • •
CUPIC FT CALCULATED NOX IC,N IDLE EVAP. LOSS TIRE
PER REV.
0.27631
S 1 4.610
KM
RPM
1443.
12?31,
FACTOR
0.9S75
COUNTS
EXHAUST Sf-MPLF
HC-FID
CO
CO?
NOX CHFM
5 2 6.127
RANGE
7
8
1
2
KM
METF.o
16.9 .
32.6
17.2
5.9
2079ft.
EXHAUST SAM'
HC-FIO
CO
C02
MOX CHFM
3 3 4.607
RANGE
7
8
1
2
KM
METER
11.6
22.7
13.9
3.3
12341.
roNC .
sryi..?'-
*•. ' . .- -*
32.8 . • !' •'
1437.0 RPM RATIO(C/A)=0.9961
KM/L-:- -•-.'.'
35.0 ,
1431.7 RPM RATIO
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