Can Synthetic Motor Oil Really Free Up Horsepower?
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In the high performance automotive world, efforts are always being made on the part of hot rodders to extract every last bit of performance potential out of their vehicles. This quest for horsepower has lead to many breakthroughs in technology used both in racing and in normal street use. The draw back to this area of interest is that in some cases, companies take advantage of consumers with either unscrupulous marketing campaigns, inferior products or a combination of both.
One area of the performance hobby that generates a great deal of interest, and often times controversy, is in the area of motor oil. Oil companies have recognized the performance facet of the automotive world and have met consumers with products they claim will give them a performance advantage. As a result, over the years, consumers have seen an almost endless barrage of products and marketing directed towards the hot rodding crowd. In some cases, these products have been hyped up to a great extent and are ultimately found to provide little or no advantage in performance over similar and less costly alternatives.
For the general consumer, just seeing a specific product on the shelf can lead him or her to recall the latest television or magazine ad where fantastic performance gains and product superiority is touted. Often times this flashy marketing is accompanied by “independent lab tests” that seem to prove what the ad claims. Unfortunately, these ads can be deceiving at times and the independent tests can be less than scientific. One such test that is designed to get to the heart and pocket book of the hot rodder is comparison of products and their demonstrated horsepower gains on a dynamometer. This is a popular tool that is sometimes used by oil company marketing.
So what is ultimately the truth? Can one really believe reported dyno results that indicate one motor oil provides a horsepower advantage over another similar motor oil? Questions like these have caused a great amount of debate and cynicism among enthusiasts.
In this thread we will look at possible inconsistencies that can generally occur with dynamometer results, synthetic motor oil friction reduction theory, and look at two motor oil dyno comparison tests that have shown a horsepower increase in switching from conventional motor oil to synthetic motor oil.
Below, Dave Young of Mopar Muscle Magazine describes dynamometer correction factors, variables in dyno testing, and inconsistencies that can occur when comparing dyno results from more than one dyno. Mopar Muscle Magazine and Amsoil, Inc., team up every year for the AMSOIL/Mopar Muscle Engine Challenge. This challenge is conducted at the Competition Cams testing facility in Memphis Tennessee where all the engines are dynoed on Competition Cams Super Flow SF-902 Engine Dynamometer.
Quote:
Originally Posted by Dave Young, Mopar Muscle Magazine, (4/2008)
Dyno Testing and Correction Factors – When testing engines on a dyno, there are several things to keep in mind. First, a dyno is a manufactured piece of equipment, so no two are identical. This inconsistency is minimal, however, as most dyno manufactures claim no more than a one percent difference between any two of their machines. Next, an engine on a dyno is subject to the same environmental inconsistencies as an engine in a car, so if the weather is hot and the barometric pressure is low, the engine will make less power. For this reason, dyno manufactures utilize sophisticated software to monitor atmospheric conditions and correct for them so that each engine is measured to the same standard, regardless of the weather. The dyno software will apply a correction factor to the measured power numbers, adjusting them accordingly for non-standard weather conditions.
There are several correction factor standards commonly used by dyno software, and these too can be inconsistent. Correction factors can vary as much as four-percent between the correction factor that gives the most power versus the correction factor that is stingiest. For this reason, engine builders commonly dyno and rate their engines based on the correction factor that shows the most power, while research facilities are more worried about consistency. Comp’s research facility uses the latest SAE (Society of Automotive Engineers) correction factor, which is considered stingy by most. So while all the engines in our contest would have likely shown more power if a more generous correction factor were used, using the SAE correction factor for all the engines made the playing field even and the contest fair.
Regardless of the weather or the correction factor used, there are other important considerations when dynoing an engine or a car. Each dyno cell is also different, and these differences aren’t easily corrected for. Turbulent air, exhaust leaking into the cell, and other factors can make dyno readings between dynos somewhat ambiguous. So the moral of the story is: Dyno numbers are really only valid when compared to numbers from the same dyno.
Theory: Synthetics and Friction Reduction
Quote:
Originally Posted by Amsoil, Inc. (08/2007)
Friction Control – Uniform, smooth synthetic lubricant molecules slip across one another easily. That minimizes friction, which in turn, improves power and fuel economy because more of the energy released from fuel combustion reaches the wheels and moves the vehicle. The vehicle accelerates more quickly and powerfully because more of the fuel goes to moving the vehicle rather than to overcoming friction. The vehicle also works more efficiently, getting better fuel economy (more miles per gallon) for the same reason – more of the fuel goes to moving the vehicle than to overcoming friction.
The famed Horsepower TV Conventional vs. Royal Purple comparison
A few years back Horsepower TV performed a Conventional vs. Synthetic motor oil comparison utilizing a Chevy ZZ4 small-block engine. The motor oil used in this comparison was a Standard 10W-30 motor oil against Royal Purple 5W-30 High Performance Motor Oil. The results of this TEST reported a gain of 8 horsepower and 6ft.lbs of torque by switching from the Standard 10W-30 to the Royal Purple 5W-30 Synthetic. This test has since been highly publicized and talked about among automotive performance enthusiasts. But how does the testing procedure used in the comparison stack up scientifically?
One inconsistency that is not hard to catch is the fact that two oil viscosities are used in the comparison. Certainly, Horsepower TV host, Joe Elmore, describes that the 5W rating for the Royal Purple oil stands for the Winter Viscosity rating, while 30 is the rating at high engine temperatures which is the same as the standard motor oil tested. Although, this may seem like a reasonable explanation, there may be an increased margin of error in comparing two dissimilar oil viscosities.
A closer look at the American Society for Testing and Materials (ASTM) test D-445 provides data on motor viscosities at predetermined oil temperatures. In this case, we will look at the Kinematic Viscosity @ 40°C, cSt. Note that 40°C equals 104°F, and cSt stands for centistokes which is the measurement of an oils viscosity while in motion. Motor oil manufacturers generally provided this information in their product data sheets which can be found online. This data was found on the Royal Purple oil used in the test but since the exact brand of the conventional motor oil was not stated, we can only draw a general conclusion on what the actual viscosity would be.
5W – At 104 degrees Fahrenheit, the 5W-30 Royal Purple has a viscosity of 65.3
10W- At 104 degrees Fahrenheit, an SAE 10W rated brand name conventional motor oil generally has a viscosity of 70. However, since we don’t know the actual brand of the black bottle “standard motor oil” used in the test, we can only assume that the viscosity would actually be around 70. This could be a conservative estimate as a generic black bottle motor oil may not perform as well as a top name brand conventional motor oil. We can only assume at this point.
So why is the difference in a 5W and 10W an issue when both oils have the same 30 rating?
