United States

Environmental Protection

Agency

Air and Radiation EPA420-R-99-001

January 1999

EPA Laboratory Evaluation of

PetroMoly HP Motor Oil

 Printed on Recycled Paper
EPA Laboratory Evaluation of PetroMoly HP Motor Oil

EPA420-R-99-001 January 1999

Vehicle Programs Group

Vehicle Programs and Compliance Division

Office of Mobile Sources

U. S. Environmental Protection Agency

NOTICE

This technical report does not necessarily represent final EPA decisions or positions. It is

intended to present technical analysis of issues using data which are currently available. 

The purpose in the release of such reports is to facilitate the exchange of technical information

and to inform the public of technical developments which may form the basis for a final EPA

decision, position, or regulatory action.
1

EPA Laboratory Evaluation of PetroMoly HP Motor Oil

Introduction

This report describes EPA laboratory fuel economy and exhaust emission testing of PetroMoly

HP 5W-30 motor oil (hereafter, PetroMoly) at EPA’s National Vehicle and Fuel Emissions

Laboratory (NVFEL) in Ann Arbor, Michigan. PetroMoly, a product of Worldwide PetroMoly

Corporation, is described in their Product Data Sheet as a high performance oil which, when used

as a replacement for a conventional motor oil, offers “Increased fuel economy up to 10%” and

“Reduced toxic emissions up to 60%” in addition to other claimed benefits. The testing reported

herein was volunteered and paid for by Worldwide PetroMoly Corporation.

Lubricants (i.e., motor oils) and lubricant additives are excluded from EPA testing under 40 CFR

Part 610.11. EPA engineers recognize that lubricants and lubricant additives have the potential to

impact fuel economy as measured in the FTP and HFET test protocols. EPA’s Vehicle Programs

and Compliance Division (VPCD) agreed to test PetroMoly on one vehicle because evidence

from independent laboratory testing conducted on two vehicles exhibited a statistically

significant improvement in fuel economy of four to five percent in city driving and two to three

percent in highway driving (see the following documents in the Appendix: Application for EPA

Evaluation, Independent Test Lab Report, and Table A-1 and Table A-2 for the EPA preliminary

analysis of the independent test laboratory data). 

The conclusions drawn from EPA evaluation tests are necessarily of limited applicability. An all

encompassing evaluation of the effectiveness of a product in achieving performance

improvements on the many types of vehicles that are in actual use would require a large sample

of test vehicles. This is not economically feasible in the evaluation projects conducted by EPA. 

Therefore, the conclusions from such tests can be considered to be quantitatively valid only for

the specific test cars used; however, it is reasonable to extrapolate the results from EPA tests to

other types of vehicles in a directional manner; i.e., to suggest that similar results are likely to be

achieved on other similar types of vehicles.

Test Program

The purpose of the EPA test program was to conduct a controlled technical evaluation of

PetroMoly in a manner that would address the manufacturer’s specific claims for significant

improvements in fuel economy and reduction in emissions. An invitation was extended to

Worldwide PetroMoly Corporation to have a representative present for all phases of

maintenance and testing.

Among the product claims made by the manufacturer of PetroMoly the following were of the

greatest interest to EPA:

1. Increased fuel economy over conventional motor oils.

2. Reduce “toxic” emissions
2

The confirmatory test plan developed by EPA (see Appendix document: Test Plan Agreement)

and agreed to by the manufacturer used a 1996 Chevrolet Lumina as a test vehicle. A description

of the test vehicle is as follows: Vehicle Identification Number (VIN) 2G1WL52M8T1162331,

Engine Family Code TGM3.1V8GFEK, 3.1 liter, with automatic transmission and 22,748 miles

on the odometer at the start of testing. The test vehicle was inspected and maintenance performed

identical to that employed on consumer owned vehicles in the VPCD in-use emissions program.

The vehicle was tuned to manufacturer’s specifications, and any malfunctioning part was

replaced as necessary. Engine oil and filter change is included in the maintenance procedure. At

the time that this test program was performed, the laboratory was using 5W-30 commercial

engine oil made by Valvoline. Once the testing program was started, no adjustments were made

to the vehicle.

The test phases were:

1. Three Federal Test Procedure tests (FTP, the simulated city drive test) and three Highway Fuel

Economy Tests (HFET) with the vehicle in stock configuration were performed to establish the

emissions and fuel economy characteristics prior to the installation of PetroMoly. No adjustments

were made to any engine components between tests.

2. After stock configuration testing with the recommended commercial weight oil (5W-30, in this

case Valvoline brand) was completed it was removed from the engine and the oil filter was

replaced with a new one, PetroMoly was added and triplicate FTP and HFET tests were

conducted to measure emissions and fuel economy characteristics with PetroMoly in the engine.

No adjustments were made to any engine components between tests.

3. PetroMoly was removed after testing the product, the oil filter was replaced with a new one

and the recommended commercial weight oil (5W-30, in this case Valvoline brand) was added

prior to conducting another triplicate set of stock configuration tests. Again, no adjustments were

made to any engine components between tests.

Results

Use of PetroMoly in the single test vehicle demonstrated the following when compared directly

to the stock configuration test using a basic 5W-30 SAE motor oil as recommended by the

vehicle manufacturer:

There was a two percent improvement in fuel economy on the city drive test. On the city drive

test, there was a five percent increase in oxides of nitrogen (NOx), a nine percent reduction in

hydrocarbons (HC) and a ten percent reduction in carbon monoxide (CO) when compared to the

stock configuration test.

There was a three percent improvement in highway fuel economy.

After removing the PetroMoly and replacing it with the recommended commercial weight oil
3

(5W-30, in this case Valvoline brand) as used in the first stock configuration test series, the three

additional returned to stock configuration tests showed three percent improvement in highway

fuel economy relative to the original tests with commercial engine oil. There was a one percent

improvement in city fuel economy compared to the first stock configuration test series. The

exhaust emissions were two, four and one percent lower for HC, NOx and CO respectively when

comparing the second stock configuration series with the first.

EPA used the same statistical analysis program for evaluating data results from independent

laboratory and EPA laboratory testing.

Complete consolidated results on emissions and fuel economy for each test along with the

average of each series are presented in Tables 1-3. Individual test bag results are to be found in

Table 4. 

Conclusions

Data submitted in the application from independent (non EPA) laboratory testing of two different

vehicles demonstrated an improvement of four to five percent in the city driving test and two to

three percent in the highway driving test associated with PetroMoly. EPA analysis of these data

showed that the improvements were statistically significant. One of the two vehicles tested also

showed a thirteen percent reduction in oxides of nitrogen which was statistically significant.

There were no other statistically significant differences in emissions.

The three percent improvement in highway fuel economy and two percent improvement in city

fuel economy measured in the EPA confirmatory testing of PetroMoly were statistically

significant improvements for testing a single vehicle. The improvements in fuel economy appear

to be retained for at least some short period after PetroMoly is replaced with a commercial engine

oil. Testing performed by EPA does not allow quantifying the duration of this “carryover”period.

Although EPA testing showed reductions of nine percent and ten percent in hydrocarbon and

carbon monoxide exhaust emissions respectively, these changes were not statistically significant.

The five percent increase in oxides of nitrogen exhaust emissions measured in EPA testing when

PetroMoly was employed is a statistically significant difference.

Fuel economy improvements were measured, but were not as large as those measured by an

independent laboratory for Worldwide PetroMoly. With exception of NOx, changes in exhaust

emissions were not significant. On the vehicle tested by EPA a statistically significant NOx

penalty of five percent was measured. A statistically significant NOx reduction of thirteen

percent was measured on one of the two vehicles tested by an independent laboratory for

Worldwide PetroMoly.
4

TABLE 1

PetroMoly vs Commercial Engine Oil -- Prior to Use of PetroMoly

Pollutant/ Fuel

Economy

Commercial Engine Oil (Valvoline

5W30). Before use of PetroMoly

PetroMoly P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.1966 0.1713 0.1785 0.1821 0.1711 0.1667 0.1606 0.1661 CO (g/mile) 2.065 1.933 2.067 2.022 1.973 1.854 1.661 1.830 

NOx (g/mile) 0.2292 0.2147 0.2168 0.2202 0.2365 0.2281 0.2306 0.2318 

"City" Fuel

Economy (mpg)

23.02 22.80 22.91 22.91 23.77 23.53 23.13 23.48 

"Highway" Fuel

Economy (mpg)

38.50 38.51 38.82 38.61 40.05 40.03 39.15 39.74 
5

TABLE 2

PetroMoly vs Commercial Engine Oil -- After Use of PetroMoly

Pollutant/ Fuel

Economy

PetroMoly Commercial Engine Oil (Valvoline

5W30). After use of PetroMoly

P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.1711 0.1667 0.1606 0.1661 0.1672 0.1621 0.2039 0.1777 CO (g/mile) 1.973 1.854 1.661 1.830 1.831 1.809 2.379 2.007 

NOx (g/mile) 0.2365 0.2281 0.2306 0.2318 0.1900 0.2209 0.2239 0.2116 

"City" Fuel

Economy (mpg)

23.77 23.53 23.13 23.48 23.23 23.05 23.23 23.17 

"Highway" Fuel

Economy (mpg)

40.05 40.03 39.15 39.74 39.50 39.53 40.04 39.69 
6

TABLE 3

Commercial Engine Oil, After Use of PetroMoly vs Commercial Engine Oil, Prior to Use of P

Pollutant/ Fuel

Economy

Commercial Engine Oil (Valvoline

5W30). Before Use of PetroMoly

Commercial Engine Oil (Valvoline

5W30). After Use of PetroMoly

P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.1966 0.1713 0.1785 0.1821 0.1672 0.1621 0.2039 0.1777 CO (g/mile) 2.065 1.933 2.067 2.022 1.831 1.809 2.379 2.007 

NOx (g/mile) 0.2292 0.2147 0.2168 0.2202 0.1900 0.2209 0.2239 0.2116 

"City" Fuel

Economy (mpg)

23.02 22.80 22.91 22.91 23.23 23.05 23.23 23.17 

"Highway" Fuel

Economy (mpg)

38.50 38.51 38.82 38.61 39.50 39.53 40.04 39.69 
7

TABLE 4

INDIVIDUAL GAS BAG DATA FOR PETROMOLY FROM EPA LABORATORY TESTS

Test Test Bag 1 Bag 1 Bag 1 Bag 1 Bag 2 Bag 2 Bag 2 Bag 2 Bag 3 Bag 3 Bag 3 Bag 3 FTP FTP FTP FT

Date HC CO NOx FE HC CO NOx FE HC CO NOx FE HC CO NOx F

BL 1-1 5/13/98 0.713 7.619 0.596 23.3 0.021 0.236 0.067 21.6 0.138 1.326 0.259 26.1 0.197 2.065 0.229 2BL 1-2 5/14/98 0.664 8.038 0.562 23.2 0.011 0.068 0.040 21.3 0.103 0.849 0.282 26.0 0.171 1.933 0.215 2BL 1-3 5/15/98 0.685 7.582 0.583 23.6 0.014 0.237 0.058 21.3 0.107 1.358 0.240 26.0 0.178 2.067 0.217 2PM-1 6/16/98 0.672 7.425 0.639 23.8 0.018 0.267 0.072 21.9 0.083 1.085 0.245 28.4 0.171 1.973 0.236 2PM-2 6/17/98 0.620 7.197 0.593 23.9 0.019 0.205 0.059 21.9 0.104 0.947 0.272 27.0 0.167 1.854 0.228 2PM-3 6/18/98 0.634 6.665 0.570 23.9 0.010 0.106 0.043 21.4 0.087 0.820 0.328 26.5 0.161 1.661 0.231 2BL 2-1 7/09/98 0.621 7.395 0.552 23.3 0.011 0.078 0.039 21.6 0.119 0.936 0.200 26.8 0.167 1.831 0.190 2BL 2-2 7/16/98 0.626 7.179 0.588 23.4 0.015 0.127 0.050 21.4 0.089 0.926 0.266 26.6 0.162 1.809 0.221 2BL 2-3 7/21/98 0.798 9.682 0.661 23.2 0.012 0.161 0.049 21.6 0.117 1.048 0.223 27.1 0.204 2.379 0.224 2HC = Hydrocarbons, grams per mile BL 1 = BaselineNOx = Oxides of nitrogen, grams per mile PM = With PetroMoly installedCO = Carbon monoxide, grams per mile BL 2 = Baseline after removal of PetroMolyFE = City fuel economy, miles per gallon
8

APPENDIX

1. Application for EPA Evaluation

2. EPA Analysis of Independent Laboratory Test Data, FTP (city drive test), Table A-1

3. EPA Analysis of Independent Laboratory Test Data, FTP (highway drive test), Table A-2

4. Independent Test Lab Report (Environmental Research &Development Corp.)

5. Test Plan Agreement
9

TABLE A-1

Statistical Analysis of Independent Test Lab Data on PetroMoly Oil Using FTP (simulated city driving

PetroMoly vs Commercial Engine Oil- Independent Lab Test Vehicle 1

Pollutant/ Fuel

Economy

Commercial Engine Oil 

Before use of PetroMoly

PetroMoly P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.1421 0.1584 0.1638 0.1548 0.1470 0.1700 0.1825 0.1665 CO (g/mile) 1.9638 2.3838 2.4890 2.2789 1.8812 2.4157 2.7616 2.3528 

NOx (g/mile) 0.2549 0.2325 0.2451 0.2442 0.2109 0.2119 0.2121 0.2116 

"City" Fuel Economy

(mpg)

20.33 20.26 20.15 20.25 21.07 21.12 21.14 21.11 

PetroMoly vs Commercial Engine Oil- Independent Lab Test Vehicle 2

Pollutant/ Fuel

Economy

Commercial Engine Oil 

Before use of PetroMoly

PetroMoly P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.1353 0.1426 0.1651 0.1477 0.1251 0.1462 0.1595 0.1436 CO (g/mile) 1.5538 1.8295 1.6475 1.6769 1.3385 1.8334 2.0420 1.7380 

NOx (g/mile) 0.1757 0.1816 0.1836 0.1803 0.1688 0.1888 0.1710 0.1762 

"City" Fuel Economy

(mpg)

19.88 19.20 19.86 19.65 20.78 20.87 20.23 20.63 

Vehicle 1 was a 1997 Dodge Stratus, 2.4 liter, Engine Family VCR2.4VJGKEK, VIN 1B3EJ46X1VN676211, with 8133 on the odometer Vehicle 2 was a 1997 Dodge Stratus, 2.4 liter, Engine Family VCR2.4VJGKEK, VIN 1B3EJ46X0VN706007, with 3039 miles on the odo
10

TABLE A-2

Statistical Analysis of Independent Test Lab Data on PetroMoly Oil Using HFET (simulated highway 

PetroMoly vs Commercial Engine Oil- Independent Lab Test Vehicle 1

Pollutant/ Fuel

Economy

Commercial Engine Oil 

Before use of PetroMoly

PetroMoly P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.1149 0.1275 0.1158 0.1194 0.1216 0.1267 0.1189 0.1224 CO (g/mile) 2.6632 3.0881 2.7715 2.8409 2.943 3.157 2.8865 2.9955 

NOx (g/mile) 0.1506 0.1673 0.1498 0.1559 0.1463 0.1589 0.1535 0.1529 

"Highway" Fuel

Economy (mpg)

35.21 35.11 35.18 35.17 35.86 35.80 36.01 35.89 

PetroMoly vs Commercial Engine Oil- Independent Lab Test Vehicle 2

Pollutant/ Fuel

Economy

Commercial Engine Oil 

Before use of PetroMoly

PetroMoly P

Di

Test 1 Test 2 Test 3 Average Test 1 Test 2 Test 3 Average

HC (g/mile) 0.0942 0.0843 0.1002 0.0929 0.098 0.089 0.088 0.092 CO (g/mile) 1.4630 1.4799 1.7029 1.5486 1.7103 No Data 1.7583 1.7343 

NOx (g/mile) 0.0451 0.0565 0.0561 0.0526 0.0560 0.0511 0.0598 0.0556 

"Highway" Fuel

Economy (mpg)

34.83 34.12 34.73 34.56 35.88 35.77 35.27 35.64 

Vehicle 1 was a 1997 Dodge Stratus, 2.4 liter, Engine Family VCR2.4VJGKEK, VIN 1B3EJ46X1VN676211, with 8133 on the odometer 

Vehicle 2 was a 1997 Dodge Stratus, 2.4 liter, Engine Family VCR2.4VJGKEK, VIN 1B3EJ46X0VN706007, with 3039 miles on the odo