1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2008 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org J1082 REI. FEB2008 SURFACE VEHICLE STANDARD Issued 1974-04 Reissued 2008-02 Superseding J1082 OCT2002 Fuel Economy Measurement Road Test Procedure RATIONALE This standard is reissued with updated references and minor
5、 editorial changes for improved clarity. 1. SCOPE This SAE Standard incorporates driving cycles that produce fuel consumption data relating to Urban, Suburban, and Interstate driving patterns and is intended to be used to determine the relative fuel economy among vehicles and driving patterns under
6、warmed-up conditions on test tracks, suitable roads, or chassis dynamometers.11.1 Purpose This document provides uniform testing procedures for measuring the fuel economy of light-duty vehicles (motor vehicles designed primarily for transportation of persons or property and rated at 4500 kg (10 000
7、lb) or less) on suitable roads. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of the specification to the extent specified herein. Unless otherwise indicated the latest revision of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE Internationa
8、l, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J1263 Road Load Measurement and Dynamometer Simulation Using Coastdown Techniques SAE J2263 Road Load Measurement Using Onboard Anemometry and Coastdown Tec
9、hniques SAE J2264 Chassis Dynamometer Simulation of Road Load Using Coastdown Techniques 1Though these test cycles can be run on a chassis dynamometer, this procedure cannot be used for compliance with mandatory fuel economy standards or fuel economy labelling for light-duty vehicles first establish
10、ed by the “Energy Policy and Conservation Act,” Public Law 94-163, 94th Congress S. 622, December 22, 1975. Details of the mandatory dynamometer procedure can be obtained by contacting Environmental Protection Agency, Fourth and M Street, S.W., Washington, DC 20460. It should be noted that correlati
11、on between chassis dynamometer and road test results has not been established. SAE J1082 Reissued FEB2008 - 2 - 2.1.2 ASTM Publication Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM D 4814 Standards Specification for Automotive Spa
12、rk-Ignition Engine Fuel 3. DEFINITIONS 3.1 Driving Cycles 3.1.1 Urban Cycle Driving pattern defined by 8.3.4 which is similar to driving conditions in the central business district of a large city. 3.1.2 Suburban Cycle Driving pattern defined by 8.3.5 which is similar to driving conditions in suburb
13、an areas of a large city. 3.1.3 Interstate Cycle Driving patterns defined by 8.3.6 and 8.3.7 which are similar to driving conditions on expressways. 3.2 Test Vehicle Passenger car or light truck prepared for test according to Section 7. 3.3 Test Vehicle Weight Unloaded vehicle weight plus 136 kg (30
14、0 lb). 3.3.1 Unloaded Vehicle Weight (Curb Weight) The weight of the vehicle as built to production parts list with maximum capacity of all fluids necessary for operation of the vehicle. 3.3.2 Driver and Passenger or Ballast Weight 136 kg (300 lb) includes occupants, instrumentation, and ballast, if
15、 necessary. NOTE: This weight will be distributed to properly simulate passenger locations and vehicle attitude (one passenger in drivers position and one passenger or equivalent weight in front seat passenger position). 3.3.3 Chassis Dynamometer Inertia Weight and Horsepower Settings These settings
16、 should be established and set in accordance with SAE J1263 or SAE J2263 and SAE J2264. 3.4 Observed Economy Observed economy is the fuel economy measured during a driving cycle. It is determined by dividing the actual kilometers (miles) driven on the cycle by the number of liters (gallons) consumed
17、. Economy should be expressed as kilometers per liter (miles per gallon). SAE J1082 Reissued FEB2008 - 3 - 3.5 Corrected Economy Corrected economy is the observed economy multiplied by the correction factors listed in Section 10. The corrected fuel economy should be expressed as kilometers per liter
18、 (miles per gallon).23.6 Correction Factors Factors which are used to adjust data to the standard ambient condition of 15.6 C (60 F) and 98.2 kPa (29.0 in Hg) and reference fuel properties. 3.7 Average Fuel Economy Average fuel economy is the total distance driven divided by the total volume of fuel
19、 consumed in a series of replicate tests. When the distance driven in each of the tests is identical, as may be assumed for this procedure, the average fuel economy is determined by taking the harmonic average of the individual economies. See Equation 1. 12 nnAverage Fuel Economy1/MPG 1/MPG 1/MPGn t
20、he number of replicate tests=+= (Eq. 1) 3.8 Test Repeatability Guidelines These guidelines are intended to provide an estimate of repeatability of test data for replicate tests and are based on a standard deviation equal to 1.9% of the mean. 3.8.1 Estimate of the 95th Percentile Range for Replicate
21、Tests The 95th percentile range (R) equals 0.019Q times the average fuel economy, where Q equals the critical value obtained from a table for the Studentized3range and the average fuel economy for n tests. Selected value for 0.019Q are as shown in Table 1: TABLE 1 - SELECTED VALUES FOR 0.019Q n 0.01
22、9Q 2 0.053 3 0.063 4 0.069 5 0.073 10 0.085 a. Example 1 (SI units)If a vehicle obtains 6.20 km/L and 6.60 km/L on two tests on the same cycle, the average fuel economy would be 6.39 km/L and the 95th percentile range would be as shown in Equation 2: R 0.053 6.39 0.34 km /L= (Eq. 2) The difference b
23、etween the two tests is 0.4 km/L which is greater than the difference that would be expected for 95% of the cases in which two tests were conducted. Consequently, additional tests should be conducted to provide more confidence in the average fuel economy. 2The corrected economy and average fuel econ
24、omy may be expressed in terms of fuel consumption, for example, L/100 km, if the appropriate conversions are made (L/100 km = 235.265/mpg). When average fuel economy is expressed as consumption, the average fuel consumption is the arithmetic average of the individual consumptions. 3D. B. Owen, “Hand
25、book of Statistical Tables,” Reading, MA: Addison Wesley Publishing Co., Inc., 1962, pp. 144-148. SAE J1082 Reissued FEB2008 - 4 - b. Example 2 (U.S. units)If a vehicle obtains 14.5 mile/gal and 15.5 mile/gal on two tests on the same cycle, the average fuel economy would be 14.98 mile/gal and the 95
26、th percentile range would be as shown in Equation 3: R 0.053 14.98 0.79 mile / gal= (Eq. 3) The difference between the two tests is 1.0 mile/gal which is greater than the difference that would be expected for 95% of the cases in which two tests were conducted. Consequently, additional tests should b
27、e conducted to provide more confidence in the average fuel economy. 3.8.2 Estimate of the Average Fuel Economy at a 90% Confidence Interval(See Equation 4.) AverageAverage at 90% Average 0.031Confidence Interval Fuel Economy Fuel Economyn = (Eq. 4) a. Example 1 (SI units)If a vehicle obtained 6.29 k
28、m/L and 6.46 km/L on two tests on the same cycle, the average fuel economy would be 6.37 km/L and the 90% confidence interval would be as shown in Equation 5: 0.0316.37 6.37 6.37 0.14 km /L2 = (Eq. 5) b. Example 2 (U.S. units)If a vehicle obtained 14.8 mile/gal and 15.2 mile/gal on two tests on the
29、same cycle, the average fuel economy would be 15.0 and the 90% confidence interval would be as shown in Equation 6: 0.03115.0 15.0 15.0 0.3 mile / gal2=(Eq. 6) 4. INSTRUMENTATION All instrumentation shall be calibrated. 4.1 Fuel The fuel measurement device must be compatible with the vehicle fuel sy
30、stem and should alter the fuel temperature and pressure as little as practical. The fuel measurement system must be accurate to within 0.5% of the fuel used during a driving cycle. 4.2 Speed The speed indicating device shall indicate vehicle speed in kilometers per hour (miles per hour) and be accur
31、ate within 1 km/h (0.5 mph). 4.3 Acceleration The acceleration indicating device must be capable of indicating both positive and negative acceleration. It shall indicate acceleration/deceleration in m/s2(ft/s2) and be accurate within 0.2 m/s2(0.5 ft/s2). (Refer to 6.5 for Chassis Dynamometer Testing
32、.) 4.4 Time The time measuring instrument must be capable of measuring the time interval to 0.1 s and be accurate within 0.1 s in 1 min. SAE J1082 Reissued FEB2008 - 5 - 4.5 Temperature The temperature indicating devices must be capable of measuring to the nearest 1 C or 2 F. Accuracy must be within
33、 1 C or 2 F. The sensing element shall be shielded from radiant heat sources. 4.6 Absolute Barometric Pressure An aneroid or mercury barometer should be used. This device should be accurate within 0.3 kPa or 0.1 in Hg. 4.7 Wind Wind speed should be measured with a device that provides an indication
34、of wind speed that is accurate within 3 km/h (2 mph). Wind direction should also be indicated. 4.8 Distance A distance indicating device is required if the tests are not conducted on a premarked course. This device must be capable of indicating distance to within 5 m (15 ft) and must be capable of a
35、ccuracy within 6 m in 1 km (30 ft in 1 mile). 4.9 Vehicle Weight Vehicle weight should be measured with a device that is accurate within 0.5% with minimum resolution of 5 kg (10 lb). 4.10 Dynamometer Inertia Weight The dynamometer inertia weight is established reflecting the inertia of the nonrotati
36、ng tires and the vehicle test weight. The inertia weight should be set to the nearest flywheel increment for mechanical inertia dynamometers or within 10 lb for electrical inertia dynamometers. 5. TEST MATERIAL 5.1 Test Vehicle The test vehicle shall be completely defined on the Test Vehicle Specifi
37、cations and Preparation Form. (The test vehicle will normally be representative of a production built vehicleany exceptions must be properly noted.) 5.2 Test Fuel Normally, service station fuel will be satisfactory for test purposes, provided that it is consistent with the manufacturers recommendati
38、ons for the vehicle and with the ASTM D 4814 standards. Specific gravity or API gravity for both gasoline and diesels shall be recorded. Also gasoline octane rating RM2+shall be recorded and other properties such as distillation and Reid vapor pressure should be recorded when available. 5.3 Lubrican
39、ts Lubricants used shall conform to the manufacturers recommendation for the predominant weather condition in which the vehicle is being tested. 6. TEST CONDITIONS 6.1 Ambient Temperature Tests should be conducted at ambient temperatures between -1 C (30 F) and 32 C (90 F). SAE J1082 Reissued FEB200
40、8 - 6 - 6.2 Wind Velocity Urban cycle tests must not be conducted when average wind speed exceeds 24 km/h (15 mph) or when gusts exceed 32 km/h (20 mph). For the Suburban and Interstate Cycle tests, these limits should be reduced to 16 km/h (10 mph) average and 24 km/h (15 mph) gusts. 6.3 Road Condi
41、tions Roads must be dry, clean, smooth, and not exceed 1.0% grade. If operating on a closed track, the start and stop points should be selected such that the schedule elevation difference is 3 m (10 ft) or less. 6.4 It is recommended that roadside markers be used to indicate the points at which spee
42、d changes are to be made as indicated in 8.3. 6.5 A drivers aid is recommended for dynamometer operations reflecting the test cycles described in 8.3. 7. TEST VEHICLE PREPARATION 7.1 Break-In The vehicle should have accumulated a minimum of 3200 km (2000 miles) of operation prior to test. At least 1
43、600 km (1000 miles) must have been driven at cycling speeds between 64 km/h (40 mph) and maximum legal highway speeds. If a closed track is available for break-in, the maximum speed should not exceed 160 km/h (100 mph). Unless the testing is specifically evaluating lubricant effects of fuel economy,
44、 care should be taken to ensure that lubricant changes or additions do not take place over the duration of the test, and that engine oil has a minimum of 3200 km (2000 miles) use prior to testing. Chassis dynamometer break-in is acceptable. All of the tires must have operated on a road or track at l
45、east 160 km (100 miles) prior to the test. Tires must have at least 75% of the tread remaining and tread must be in good condition. For dynamometer testing, the vehicle should have experienced at least 800 km (500 miles) of cyclic break-in for the tires and brakes. 7.2 Inspection The vehicle must be
46、 inspected and adjusted where necessary to meet manufacturers specifications. Checks are specified on the Test Vehicle Specifications and Preparation Form (Figure 1). 7.3 Instrumentation The fuel measuring device and other instrumentation, as necessary, must be installed in a manner not to hinder th
47、e vehicle operation or operating characteristics. 7.4 Test Weight The vehicle weight must be adjusted to provide the test weight indicated in 3.3 (this test weight includes instrumentation and operator). 7.5 Tire Pressure The cold tire pressure should be the minimum recommended by the manufacturer f
48、or the vehicle test weight and should be set before vehicle operation immediately prior to the vehicle warm-up at the beginning of the test. 8. TEST PROCEDURE 8.1 Warm-Up The vehicle must be driven a minimum of 32 km (20 miles) at 90 km/h (55 mph) or maximum legal highway speed to stabilize engine a
49、nd driveline operating temperatures immediately before running the first driving cycle. SAE J1082 Reissued FEB2008 - 7 - FIGURE 1 - TEST VEHICLE SPECIFICATIONS AND PREPARATION FORM 8.2 Vehicle Controls 8.2.1 Air conditioning compressor, headlamps, and other accessories that consume power should be turned off unless required for safe vehicle operation. The battery should be f
