Introductory Remarks Since 2002, this website has been conducting a long-term study on the longevity of synthetic motor oil.
Down the hatch! Our LS1 gets its Mobil 1.
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We accept that for most people in most cars, regular old "dinosaur juice" mineral-based motor oil will work just fine. We have seen plenty of cars run beyond 150,000 miles and 200,000 miles using the stuff as long as the oil is changed regularly. However, not everyone is content with "good enough". Some want extra protection for their engines because they drive hard, or live in the city, or go racing, or because they have a crazy expensive engine. Others consider 150,000 miles to be broken-in, and seek to double or triple that vehicle service life. We hear from owners of fleet vehicles where saving a few oil changes per year on an entire fleet of vehicles equates to thousands of dollars saved. And we hear from those concerned about reducing the environmental impact of used motor oil by reducing the number of oil changes for all our cars.
When you have a product that appeals equally to tightwads, racers, industrialists, and environmentalists, it's worth a closer look, no?
But then there's a lot of trouble getting any useful information about synthetic motor oil. Which is best? Which is good enough? How much protection do they really offer? How long can you really use them? The answers are generally shrouded in marketing-speak, buried under superlatives like "proven technology" or "industry leader", accompanied by bar graphs of results from esoteric laboratory tests that seem to have little to do with real-world driving. Indeed, they mostly seem to promote the quality of the oil when new, a condition that lasts for about the length of time it takes for it to go from the mouth of the bottle to the end of the funnel.
Those curious about the finer details of motor oil have found the available material wanting. After some bickering in a Jaguar community forum about motor oil, where most of the available arguments started with "My pappy always..." (no doubt other enthusiasts are familiar with this line of logic), this website launched the Synthetic Oil Life Study, on the premise that we would continue to test as long as readers continued to help fund. The readers certainly have held up their end of the deal. We hope that our end proves satisfactory.
It is our hope that this study eventually answers these questions:
What happens to synthetic oil after it leaves the laboratory tests and gets poured into an actual engine out on real roads? In general terms, is synthetic oil capable of living up to the hype? Which one is best? (Or, Which one is best for a given application?)
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We started this study with Mobil 1 because it was what we were already using. Then we moved on to Amsoil, the independent brand most critical of Mobil 1. At present we are re-testing Mobil 1 to see what effect break-in may have had on our prior results. Once this phase is done, we will test Red Line. After that, Royal Purple, or perhaps Castrol GTX (to see how a quality mineral oil stacks up).
At the beginning of the study, we went to some effort to select an independent oil analysis firm. After examining the credentials, background, and reputation of several companies, we have selected Blackstone Laboratories as our analysts. The selection has proven fortuitous, as their service has been excellent. They are not providing us any consideration or service that you couldn't get just the same as us. We're even paying for the tests just like anybody else would.
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0 James Ashbaucher 1,000 Peter Childers 2,000 Ted Hoefer 3,000 Ted Hoefer 4,000 "Tochatihu" 5,000 Kenneth Thompson 6,000 Mark Koch 7,000 Larry Shute 8,000 Henry Gonshor 9,000 Peter Childers 10,000 John Hofstetter 11,000 Alexander Komarov 12,000 George Mertz 13,000 "Richsaab" 14,000 "Richsaab" 15,000 Mr. K.K. 16,000 Mr. K.K. 17,000 Tom Johnson 18,000 Lee "Stryder" Bussy 19,000 Steve Williams 20,000 David Kira 21,000 Daniel Kirsch 22,000 Jeff Blundell 23,000 Keith Kochman 24,000 Von Odenwald 25,000 Robert Miller 26,000 Robert Miller 27,000 Robert Miller 28,000 "RTH" 29,000 "RTH" 30,000 Glenn Schroeder 31,000 Louis Kwan 32,000 Ralph Coleman 33,000 Roy O'Kelly 34,000 James Ashbaucher 35,000 Karl Knab 36,000 Karl Knab 37,000 Karl Knab 38,000 Karl Knab 39,000 Karl Knab 40,000 A.E. Mouse 41,000 You? Please? Mobil 1 Purchase Honor Roll Bryan Savage Bryan Savage Bryan Savage--------------------------------------------------------------------------------
Blatant Plea for Help Speaking of paying for things, each analysis costs us 20 bucks. While we like to provide technical info for the public good,this particular project costs us a lot of money, essentially negating any economic benefit we will ever see from our own results. You readers, however, get all the benefit of this study at no cost. If you find this article informative, if you think it might save you a lot of money down the road (and we hope it does!), then we ask that you consider paying for one of the oil samples. It's $20.00, a low cost if each person just buys one. We'll put your name next to one of the analysis results so everyone will know what a nice person you are. Write us if you're willing to help defray the costs of this study. We're PayPal-friendly.
Links to this page are also much appreciated.
At this point it's safe to say the Mobil 1 re-test phase of the study is completely paid for. We're still grateful for donations, don't get us wrong, but we're getting into the Red Line test by now. We still appreciate the support, but please understand that "your" test results may not be posted for a long time.
Now that the Mobil 1 and Amsoil phases of the study are over, the primary author is available for online Q&A sessions in your discussion forums. If you're interested, write us for details. We see you guys discussing this study, so c'mon, why not ask questions directly instead of just guessing!
Also, if you notice that we are sometimes running late in posting new information, it's because we're busily trying to operate our start-up business, West Virginia Riders. Please cut us a little slack. New businesses are time-consuming, but we'll post the latest oil study data just as fast as we can.
Test Procedures
The test car. We can live with it.
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The test vehicle is a 2002 Chevrolet Camaro Z28. It has an aluminum
5.7L V8 (dyno tested at 307 hp) and a six-speed manual transmission. Its miles are split nearly 50/50 between city and highway, about 60 to 80 miles a day in spurts of 15 to 30 miles per trip. It tends to get around 20 mpg over the course of a month. Its regimen prior to this study was Mobil 1 5W30 oil and a NAPA Gold filter every 5,000 miles. This study began at the 10,000-mile mark; at that point, we filled it again with Mobil 1 5W30 and installed a new NAPA Gold filter. We sent a sample of new oil as a baseline. Then, we've been sampling the oil every 1,000 miles to clearly establish trends. We change the filter whenever the insolubles level reaches 0.5% (hey, we want to keep this test as objective as possible, but not at the-------------------------------------------------------------------------------- Sidebar Questions & Answers
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cost of our engine!). The oil stays in the engine until analysis shows it is no longer safe to use.
Keeping the crankcase filled to the right level can definitely be an issue with change intervals far beyond the standard 3,000 miles. All cars naturally consume a small amount of oil; for this test, we also lose oil to the analysis samples and to filter changes. The samples and filters are a static quantity so they will be equal across all brands of synthetic; however, if one type of synthetic is more prone to consumption than another, it might appear to have an advantage from more frequent refreshing. To mitigate this, we will return the oil level to the full mark immediately following each sample extraction. We will also record the amount of oil required to top it off and provide this information along with the test results. If a synthetic oil has a "long life" because it loses an inordinate amount and must be topped off frequently, that's important to know as it significantly alters the cost and longevity of the oil.
If any brand of oil should make it to a second filter change -- which so far has never happened -- then it will naturally get an extra boost from the post-filter top-off. However, this is not a concern because it reflects the real-world economics of using
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that particular brand of oil. We will, of course, report all filter changes.
To prevent a previous test oil from contaminating a new test oil, we run a 3,000 mile buffer of the new oil between tests. During the buffer interval we put in fresh spark plugs. After 3,000 miles, we drain the crankcase and refill with fresh oil, change the oil and air filters, then resume the study.
Also, just for grins, we reset the car's oil change indicator to see how GM's engineers did when they calibrated the oil life computer.
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Oil Analysis The oil is analyzed for many different things. The most critical characteristics for the purposes of oil longevity are:
Viscosity: This is the SUS viscosity at 210 degrees. It is the standard SAE viscosity measure; SUS is the unit of viscosity. This value should remain within its grade, or plus or minus 20%, whichever is greater. TBN: The Total Base Number. This is a measure of acid-combatting additives. Oil is essentially expired once it reaches a TBN around 1. Insolubles: This is the percentage of the test sample consisting of solids. Solids are always bad; the value should be less than 0.6%. Wear Metals: The presence of wear metals is a contaminant and the rate of accumulation is an indicator of the oil's protective condition. The exact values representing oil change time is rather subjective; we use Blackstone's conservative guidance in conjunction with other industry experts. Iron, copper, and lead are normally the ones to watch.
Think your corner station mechanic is gonna do this?
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The oil analysis also checks for fuel, antifreeze, and water in the oil. Of course, ideally all of these values should be zero, but realistically the tolerable limits are: fuel, 2%; antifreeze, 0%; and water, 0.05%.
Also, there's the analysis of elements expressed in parts per million. Some of these elements are indicators of engine wear, while others are additives in the oil. For any of these, the presence or absence of any element is less important than how the values change over time.
Engine Wear: aluminum, chromium, iron, copper, lead, tin, molybdenum, nickel, manganese, silver, titanium, posassium, and silicon. Anti-Wear Additive: molybdenum, phosphorus, and zinc. Antifreeze Inhibitor: potassium, boron, silicon, and sodium. Detergent Additive: boron, calcium, magnesium, and barium. Note that molybdenum and silicon can be both an additive and an indicator of engine wear.
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Past Results To date we have completed our tests of Mobil 1 and Amsoil. Mobil 1 held on for 18,000 miles, and didn't need its first oil filter until 12,000 miles. For all the details, visit our Mobil 1 Test Results page. Amsoil was time-limited to 14,000 miles (its year ran out), but it made it the whole way without a replacement filter. It's not a total success story, though, as it had some trouble with its viscosity. To read all about it, visit our Amsoil Test Results page.
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Mobil 1 5W30 SuperSyn At present we are re-testing Mobil 1 to determine what effect the engine's break-in period may have had on our previous test results. The first two samples, F1000 and F3000, are from the flush period. Oil Miles F1000 F3000 0 1000 2000 3000 4000 5000 6000
Aluminum 1 2 0 1
Chromium 0 1 0 0
Iron 5 9 1 4
Copper 14 30 0 10
Lead 2 4 0 1
Tin 0 1 0 0
Molybdenum 53 58 78 63
Nickel 0 0 0 0
Manganese 0 0 0 0
Silver 0 0 0 0
Titanium 0 0 0 0
Potassium 0 0 0 0
Boron 122 130 59 53
Silicon 8 10 4 4
Sodium 5 5 4 3
Calcium 2318 2374 2507 2248
Magnesium 63 88 11 23
Phosphorus 640 733 599 651
Zinc 732 883 710 808
Barium 0 0 0 0
Viscosity 60.2 61.3 65.1 61.0
Flashpoint 380 415 425 405
Fuel