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Motor Oil Comparison

Motor Oil Comparison

Motor Oil Comparison Test - Overview - May 2013 ( The same report in pdf format... click here)

AMSOIL Signature Series Synthetic Motor Oil
Castrol Edge® with Titanium Fluid Strength Technology® Lucas Synthetic
Mobil 1™ Extended Performance
Pennzoil Ultra™
Petro-Canada SUPREME Synthetic™
Quaker State Ultimate Durability™
Red Line High Performance Motor Oil
Royal Purple High Performance Motor Oil
Valvoline SynPower® Full Synthetic Motor Oil

While conventional motor oil sales remain flat, synthetic motor oils continue to demonstrate strong annual growth. Motorists now recognize that synthetics legitimately improve engine performance, particularly in engines that operate under severe service. Performance cars and many traditional family vehicles today leave the factory with synthetic oil installed and recommended as the ser-vice fill, contributing to synthetics’ increased demand. Oil manufacturers have responded. Many now formulate multiple synthetic motor oils, often led by a flagship product that represents each company’s most advanced technology.


Compare the performance in laboratory tests and cost-effectiveness of AMSOIL Signature Series Synthetic Motor Oil to several passenger-car/light-truck synthetic motor oils widely considered by marketers and con-sumers to be the best available.


Laboratory bench testing conducted in accordance with American Society of Testing and Materials (ASTM) procedures examined several important areas of motor oil performance, including resistance to deposit formation, wear protection, high-temperature stability, resistance to acid formation and cold-temperature performance. Bench tests are used widely to differentiate between formulations.
Note: Test results published in this Technical Study describe and represent properties of oils that were acquired on the dates listed in Table 1 (page 3). Results do not apply to any subsequent reformulations of such oils or to new oils introduced after completion of testing. All oils were available to consumers at the time of purchase. Testing was completed February 2013 by an independent, third-party lab. Formulations were coded to eliminate bias, and samples were tested in random order. An appropriate number of trials of each oil were run to produce results at the 95 percent confidence level when compared to Signature Series Synthetic Motor Oil.1

ASTM Tests Performed
Each oil was subjected to the following ASTM test methodologies:
  • Four-Ball Wear Test (ASTM D 4172 Mod.)
  • Total Base Number (ASTM D 2896)
  • Cold Cranking Viscosity (ASTM D 5293)
  • Thermo-Oxidation Engine Oil Simulation Test (TEOST, ASTM D 6335)
  • NOACK Volatility Test (ASTM D 5800)


1 The 95 percent confidence level only applies when comparing AMSOIL Signature Series 5W-30 Synthetic Motor Oil to the other oils. The 95 percent confidence level does not apply when comparing the other oils to one another


Candidate Oils

The following 10 synthetic motor oils were selected. All oils were 5W-30 and are recommended for the American Petroleum Institute (API) SN and International Lubricants Standardization and Approval Committee (ILSAC) GF-5 performance specifications.
Motor Oil Acquired Batch Code API / ILSAC Specification
AMSOIL Signature Series Synthetic Motor Oil Nov. 2012 15455 298 SN/GF-5
Castrol Edge with Titanium Fluid Strength Technology Dec. 2012 A1229220921 H1 SN/GF-5
Lucas Synthetic Nov. 2012 12206 I512:33 SN/GF-5
Mobil 1 Extended Performance Dec. 2012 11012L04A 15 5888 SN/GF-5
Pennzoil Ultra Dec. 2012 10413471 U001 22MAR12 0701 1 SN/GF-5
Petro-Canada SUPREME Synthetic Dec. 2012 121019LX 011137 122163*
121019LX 011154 122163*
121019LX 011186 122163*
Quaker State Ultimate Durability Dec. 2012 10492378 U002-1 11OCT12 15:13 SN/GF-5
Red Line High Performance Motor Oil Nov. 2012 62286 9343P-003442 SN/GF-5
Royal Purple High Performance Motor Oil Dec. 2012 ICPR33A18201 SN/GF-5
Valvoline SynPower Full Synthetic Motor Oil Dec. 2012 J2212C5 1949 SN/GF-5


* Individual liters originated from the same case (code 121019LX 00930).


Four-Ball Wear Test (ASTM D 4172 Mod.)
According to the ASTM, the Four-Ball Wear Test “can be used to determine the relative wear preventive properties of lubricating fluids in sliding contact under the prescribed test conditions. No attempt has been made to correlate this test with balls in rolling contact. The user of this test method should determine to his own satisfaction whether results of this test procedure correlate with field performance or other bench test machines.”
1 Although not widely used as an engine oil test, the Four-Ball Wear Test provides a means of comparing relative wear-protection properties of lubricating oils. To better differentiate between lubricants, the severity of the test was increased with higher rpm and temperature (the test standard allows for running the test under modified parameters). The size of the scar as a result of the test indicates the level of wear protection the lubricant provides.

Four-Ball Wear Test (ASTM D 4172 Mod.)
1,800 rpm, 150ºC, 40 kg. 1 hour
Performed by independent, third-party lab February 2013.
The smaller the wear scar, the better the performance in the test.
Motor Oil Comparison - Four Ball Wear Chart
Four-Ball Wear Test results indicate significant differences in relative wear protection between oils. The top four performers limited wear scars to under 0.40 mm. AMSOIL Signature Series Synthetic Motor Oil demonstrated the best wear protection in the Four-Ball Wear Test.



Total Base Number (ASTM D 2896)

Total Base Number (TBN) is the measure of a lubricant’s reserve alkalinity, which aids in the control of acids formed during the combustion process. TBN can also be used as a measure of lubricant degradation in service.

1 Motor oils that have a high TBN and demonstrate good TBN retention are known to effectively reduce the corrosive effects of acids over an extended period.

Total Base Number (ASTM D 2896)
Performed by independent, third-party lab February 2013.

The higher the number, the better the performance in the test.
Motor Oil Comparison - Total Base Number Chart


AMSOIL Signature Series Synthetic Motor Oil tested two numbers higher than the nearest competitor.




Cold Cranking Viscosity (ASTM D 5293)

The Cold Crank Simulator Test determines the apparent viscosity of lubricants at low temperatures and high shear rates. Viscosity of lubricants under these conditions is directly related to low-temperature engine cranking.

1 The test was performed at -30ºC (-22ºF). Results are reported in centipoise (cP), with lower values reflecting easier cold starts and reduced battery strain. To meet the API SN and ILSAC GF-5 motor oil specifications, a motor oil’s cold crank viscosity must not exceed 6,600 cP.


Cold Crank Viscosity (ASTM D 5293)
cP @ -30ºC (-22ºF)
Performed by independent, third-party lab February 2013.

The lower the value, the better the performance in the test.
Motor Oil Comparison - Cold Crank Viscosity Chart



Although synthetic motor oils are known to provide increased low-temperature performance compared to conventional oils, results suggest performance differences between formulations. AMSOIL Signature Series Synthetic Motor Oil demonstrated the lowest cold-crank viscosity (3,727 cP).



Thermo-Oxidation Engine Oil Simulation Test (TEOST, ASTM D 6335)

Motor oils can form deposits when exposed to increased heat, reducing efficiency and contributing to poor overall performance. According to the ASTM, the TEOST test method “is designed to predict the high temperature deposit forming tendencies of an engine oil. This test method can be used to screen oil samples or as a quality assurance tool.”
1 Given the number of vehicles now equipped with direct fuel injection, turbochargers and other performance-enhancing technologies that increase heat, deposit control has taken on increased importance. To meet the API SN Resource Conserving and ILSAC GF-5 motor oil specifications, a 5W-30 motor oil must limit total deposit formation to 30 mg or less.


TEOST Test (ASTM D 6335)
Performed by independent, third-party lab February 2013.

The lower the value, the better the performance in the test.
Motor Oil Comparison - TEOST Chart



Results demonstrate a range of performance differences between oils. Only Castrol Edge with Titanium Fluid Strength Technology and AMSOIL Signature Series Synthetic Motor Oil limited total deposit weight to 5 mg or less.



NOACK Volatility Test (ASTM D 5800)

The NOACK Volatility Test determines the evaporation loss of lubricants in high-temperature service. According to the ASTM, “Evaporation may contribute to oil consumption in an engine and can lead to a change in the properties of an oil.”

1 As with the TEOST test, low values in the NOACK Volatility Test are of particular benefit in modern, hot-running engines.

In the NOACK test, a candidate oil is exposed to heat and circulating air. Following 60 minutes, the remaining oil volume is weighed and compared to the original weight, with the difference reported as the percentage of weight lost. Results must be limited to 15 percent or less to meet the API SN and ILSAC GF-5 specifications.


NOACK Test (ASTM D 5800)
Performed by independent, third-party lab February 2013.

The lower the value, the better the performance in the test.
Motor Oil Comparison - NOACK Volatility Chart



While all oils were below the API SN and ILSAC GF-5 upper limit, results indicate differences in high- temperature volatility. Half of the oils limited the percentage weight lost from volatility to under 10 percent, with AMSOIL Signature Series Synthetic Motor Oil having the third-best result.



Overall Annual Cost

Although AMSOIL Signature Series Synthetic Motor Oil is recommended for 25,000 miles/one year in normal service 1, light-duty vehicles accumulate an average of 11,318 miles a year 2 and are generally used in driving conditions that fall under the severe service 3 category. For those reasons, overall annual cost is evaluated at 11,318 miles under severe service driving conditions. Signature Series Synthetic Motor Oil carries a drain in-terval of up to 15,000 miles/one year, whichever comes first, in severe service. Because the other nine oils do not carry a recommended drain interval, a drain interval of 4,777 miles was used, which represents the aver-age drain interval of motorists as reported in the 2012 National Oil & Lube News Operator’s Survey. Although Mobil 1 Extended Performance is recommended for 15,000 miles in out-of-warranty vehicles in certain driving conditions, its extended drain recommendation does not apply for this evaluation. According to the official statement on the Mobil 1 Extended Performance label, “Extended service is not recommended in severe service applications involving racing and commercial use, frequent towing or hauling, extremely dusty or dirty conditions, or excessive idling.”

Per-quart prices (Table 2) reflect the MSRP where available or average of a cross-section of retail outlets surveyed January 2013. Costs are based on a five-quart capacity. Overall value represents the cost of the oil only.

Motor Oil Comparison - Cost of Ownership Chart


1 AMSOIL defines normal service as personal vehicles frequently traveling greater than 10 miles at a time and not operating under severe service.

2 “Average Vehicle Distance Traveled in Miles and Related Data – 2011 (1) By Highway Category and Vehicle Type”.

3 AMSOIL defines gasoline engine severe service as turbo/supercharged engines; commercial or fleet vehicles; excessive idling; daily short-trip driving less than 10 miles (16km); frequent towing, plowing or hauling; dusty-driving conditions; or in vehicles with 100,000 or more miles that will be using AMSOIL engine oil for the first time.

Annual Cost Per 11,318 Miles in Severe-Service Conditions
Five-quart capacity. Cost of oil only. Based on MSRP where available or a
cross-section of retail outlets surveyed January 2013.

Motor Oil Comparison - Cost of Ownership in 11,318 miles Chart
* Not recommend for extended service in vehicles used in severe-service driving conditions. See official statement on the Mobil 1 Extended-Performance label.


Though the retail price per quart of AMSOIL Signature Series Synthetic Motor Oil is initially higher, it provides lower costs compared to the other oils. Overall, Signature Series is the most cost-effective oil.



AMSOIL Signature Series Synthetic Motor Oil ranked first in four of the six comparisons. In contrast, while some oils performed well in a few areas, they did not perform as well in others. Different results from one test to another indicate an emphasis in one area of performance does not correspond to increased performance in other areas of testing. It also reveals the difficulty inherent in formulating a high-quality motor oil that performs well in tests designed to assess optimum engine protection and life.

As engines continue to evolve and demand more from motor oil, the need for premium lubrication becomes more critical. Industry-standard testing performed by an independent, third-party laboratory reveals AMSOIL Signature Series Synthetic Motor Oil to be the overall top-performing oil in these tests. When considering the savings of time and money available due to its 15,000-mile/one-year drain interval in severe service, Signature Series is also the most economical choice.

- AMSOIL - the best synthetics -

Amsoil from 1972 has delivered a stellar lubrication product line with the highest level of performance, from wear prevention to fuel mileage savings in a product of vastly longer drain capabilities. Amsoil is proven to be the best oil available on the market by independent laboratory comparison tests and did exceptionally fine in my tests too.

What this means for you is unheard of convenience, the greatest fuel economy changine oil can do for your vehicle and piece of mind knowing the very best lubrication technology is protecting your vehicle beyond other synthetic oils and well beyond petroleum oil.

Do you think that oil is oil so who cares what I use?
Do you buy the cheapest oil you can thinking you're saving money?

Respectfully, know that petroleum oil does not save you money...

yes, it's the cheapest oil to buy, BUT NOT TO OWN

Like anything of quality, the benefits quality brings are why Amsoil is well worth your consideration.

Amsoil has for decades compared the performance of their lubricants against the competition by hiring independent labs to performance test oil that the labratory buys off the store shelf.

Other oil companies don't publish their oil performance comparing theirs to the competition, why is that?

Amsoil openly publishes their results, reports such as these are readily available;

Amsoil Performance Comparisons
Motorcycle Oil Comparison - Archive from 2009
Compressor Oil Comparison
Gear Oil Whitepaper
Grease Pound-Out is always an Issue - or is it? <a href="">LinkedTube</a>  
Amsoil Interceptor vs BRP XPS-2
in E-TEC 800R
<a href="">LinkedTube</a>
Scheuring Racing Ski-Doo Testimonial
<a href="">LinkedTube</a>  

Amsoil Interceptor vs BRP XPS-2 Synthetic
in E-TEC 800R
(same as above)

Interceptor vs XPS-2 Synthetic BRP

Amsoil Interceptor after 3469 miles in BRP E-TEC

Interceptor oil study in Ski-Doo E-TEC

Amsoil has never been sued for publishing its competitor's
oils (sometimes) embarrasing performance results.

This can mean but one thing. The results are true

Producers of regular commodity grade motor oil would like you to think that 'oil is oil' so shop for the cheapest as it's all the same anyway! And they're right actually, regular motor oils do tend to be the same in performance capability except regular grade oil producers leave out the rest of the story! With the information available on this site you will come to know that;

There is a W I D E range of lubrication performance between great and regular commodity grade oil.

Advertising hype is everywhere with everyone claiming to have the best oil there is. This is very confusing on the surface, but you can determine very quickly if your oil of choice is a premium product or like 95% of the rest of the market, a commodity grade product no better than every other commodity grade product.

Here's the question to ponder...
Does the manufacturer of the oil you use now openly compare
their products' performance to their competition?

Is the answer no?... with Amsoil the answer is yes...

Speaks volumes about product performance and confidence in your product to do so don't you think?...

Are API approved synthetic oils "good enough?", apparently not...

Lube's DIRTY Secret - (August 2003 Service Station and Garage Management)
"some lubricants sold in North America could actually be hazardous to engines..."
(full article...)

Conventional Oil Costs Carmaker $32 Million -
...owners weren't advised to use synthetic oil. (full article...)


"Lubes' n' Greases" Automotive Editor David McFall, once with the American Petroleum Institute tackled the issue of extended drain intervals in his March 2003 column, criticizing the standard 3,000-mile oil change and referring to the American motor oil market as "shackled."

"Lubes' n' Greases" December 2003: Addressing the ethical aspects of keeping drain intervals shortened, David McFall declares, the current stance of the oil industry “comes at a high environmental price.” December 2003 column

Amsoil, the Company of Firsts is the largest independent synthetic oil manufacturer in the world and has a documented history of innovation and leadership.

Here's some background:

  • First to develop an API-rated 100 percent synthetic motor oil.
  • First to introduce the concept of "extended drain intervals" with a recommended 25,000-mile/1-year drain interval.
  • First U.S. company to utilize the NOACK volatility test as a standard of performance excellence.
  • First to produce synthetic motor oils for diesel engines, racing engines, turbo and marine engines.
  • First to introduce synthetic oils that legitimately contribute to improving fuel efficiency.
  • First to manufacture synthetic gear lube for automotive use.
  • First to manufacture a 100:1 pre-mix synthetic 2-cycle oil.
  • First to manufacture a synthetic automatic transmission fluid for automotive use.


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