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© 2005 Brian F. Schreurs
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Amsoil ASL 5W30

Down the hatch! Our LS1 gets its Amsoil.

Test Sample Results

CLICK THE GRAPHIC FOR A FULL-SIZE VIEW Oil Miles 0 1000 2000 3000 4000 5000 6000 7000 8000 Aluminum 0 1 2 2 2 3 3 3 4 Chromium 0 1 1 1 1 1 1 1 1 Iron 0 9 11 10 12 12 13 15 16 Copper 0 31 58 63 69 65 65 69 64 Lead 0 2 2 3 6 3 7 10 10 Tin 0 0 2 0 1 0 2 0 0 Molybdenum 0 0 0 0 1 0 0 5 5 Nickel 0 0 0 0 0 0 0 1 1 Manganese 0 0 0 0 1 1 1 1 1 Silver 0 0 0 0 0 0 0 0 0 Titanium 0 0 0 0 0 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 1 Boron 82 66 62 53 47 40 36 33 33 Silicon 2 8 10 9 9 9 9 10 10 Sodium 1 2 1 2 2 2 3 3 3 Calcium 2321 2222 2433 2133 2086 2214 2308 2331 2048 Magnesium 728 733 798 716 694 717 821 793 738 Phosphorus 965 1103 963 877 856 807 869 867 916 Zinc 1113 1125 1192 1054 978 1033 1133 976 1057 Barium 0 0 0 0 0 0 0 0 0 Viscosity 66.2 63.7 64.8 65.2 66.4 67.6 67.8 68.0 71.6 Flashpoint 425 405 410 405 410 410 380 405 415 Fuel <0.5% <0.5% <0.5% <0.5% <0.5% <0.5% <0.5% <0.5% <0.5% Antifreeze 0% 0% 0% 0% 0% 0% 0% 0% 0% Water 0% 0% 0% 0% 0% 0% 0% 0% 0% Insolubles 0% 0.3% 0.4% 0.2% 0.3% 0.3% 0.3% 0.4% 0.3% TBN 12.5 8.3 5.1 4.3 3.3 3.6 3.5 3.0 2.4   Oil Miles 9000 10000 11000 12000 13000 14000 15000 16000 17000 Aluminum 4 3 4 4 4 4       Chromium 1 1 1 1 1 2       Iron 17 16 17 17 19 23       Copper 69 60 66 57 65 69       Lead 12 11 13 14 14 16       Tin 0 2 2 3 3 4       Molybdenum 5 5 4 3 3 5       Nickel 1 1 1 1 1 1       Manganese 1 1 1 1 1 1       Silver 0 0 0 0 0 0       Titanium 0 0 0 0 0 0       Potassium 1 0 1 2 0 0       Boron 26 32 23 26 31 31       Silicon 11 9 11 10 11 12       Sodium 3 3 3 3 3 4       Calcium 2047 2109 2234 2882 2184 2247       Magnesium 733 731 744 748 744 880       Phosphorus 828 867 879 868 895 816       Zinc 1118 1055 1255 1121 1048 1016       Barium 0 0 0 0 0 0       Viscosity 71.5 70.8 74.2 74.6 74.2 77.5       Flashpoint 410 385 400 425 380 395       Fuel <0.5% <0.5% <0.5% <0.5% <0.5% <0.5%       Antifreeze 0% 0% 0% 0% 0% 0%       Water 0% 0% 0% 0% 0% 0%       Insolubles 0.4% 0.3% 0.4% 0.4% 0.4% 0.5%       TBN 1.9 2.4 1.8 1.9 2.0 1.8

Mile 0 -- Kristin Huff, November 19, 2003.
Oil/Vehicle miles: 0 / 30,976
Oil added after sample: none

As with Mobil 1, this first sample is a virgin sample straight out of the bottle. This is our first opportunity to directly compare Amsoil to Mobil 1, and what we see is fascinating. Amsoil seems to take a completely different approach to its additive package than Mobil. Where Mobil relies on molybdenum, boron, and huge doses of calcium, Amsoil has no moly at all, less than half as much boron, and almost a third less calcium. Phosphorus is similar in both formulas, but Amsoil uses more zinc and almost thirty times more magnesium!

Amsoil's viscosity is also higher, putting it midrange for a 5W30 oil while Mobil 1 tends toward the low end of the range. TBN is marginally higher for Amsoil, 12.5 over 11.8 for Mobil 1. Whether this edge will hold over time is something that remains to be seen.

Mile 1000 -- C. Philip Houck, December 11, 2003.
Oil/Vehicle miles: 997 / 31,973
Oil added after sample: none

Okay, with our first Amsoil sample in, you can start sending the hate mail. We know that from this point forward, nothing we say will go un-flogged by the armchair critics out there.

We note that initial wear is significantly reduced from the Mobil 1 sample. Is it the oil at work, or just the natural aging of the engine? Time will tell, we suspect. The first 3,000 miles showed the most wear on Mobil 1, so if Amsoil can buck that trend then it will hold a significant advantage in the long term. Also note that even with over 30,000 miles the copper is still crazy high (hello GM, do your cams ever break in or what?). Insolubles once again jump immediately to 0.3%. If we had to guess, we'd say this is the limit of the filter's abilities, and we're not likely to ever see better than that. Viscosity dropped a bit, something Mobil 1 didn't do, but it remains significantly higher than Mobil 1's viscosity at this stage. Round one, advantage: Amsoil. Clapclapclap.

Mile 2000 -- Stephen Schreurs, January 5, 2004.
Oil/Vehicle miles: 1,985 / 32,961
Oil added after sample: 1/2 quart

The Amsoil still looks like yummy maple syrup -- as it should. This part of the test is what we technically refer to as the "boring part" -- any oil ought to get through the first 5,000 miles without incident. But, it's instructive to watch its behavior nonetheless -- viscosity fluctuation, the TBN plunge, and so on. It also looks like the LS1's cam bearings haven't finished breaking in, as the copper wear is still quite high. We also note with great interest that Amsoil has already lost over 50% of its virgin TBN, whereas Mobil 1 had lost perhaps 30% by this stage. But it's long-term TBN retention that matters, so it could hold steady yet.

Mile 3000 -- Stephen Schreurs, January 27, 2004.
Oil/Vehicle miles: 2,996 / 33,972
Oil added after sample: none

The oil looks fine -- dark amber syrup still -- but the car's sprung a coolant leak, so we were curious to see if anything unusual showed up in testing. Nothing did, thankfully; the dealer's had no luck tracing the leak, so whatever it is, it's darn minor. Copper isn't increasing quite as quickly as it was with Mobil 1, but it's too early to tell with other wear metals. The continued drop in TBN is expected; Mobil 1 didn't level off until 4,000 miles (and keep in mind that these TBN figures aren't directly comparable to the Mobil 1 figures in terms of absolute value). All in all, everything's going swimmingly, but to this point there doesn't seem to be a clear advantage of one over the other.

Mile 4000 -- Lee Weber, February 18, 2004.
Oil/Vehicle miles: 3,990 / 34,966
Oil added after sample: 1/2 quart

Appearance-wise, the oil still looks normal enough, and we haven't noted anything unusual over this interval. So far so good. The sample itself holds few surprises; we note a sudden uptick in lead, and the TBN continues its descent -- but it should level off about now. But, basically, the oil's doing fine.

Mile 5000 -- "Richin Chicago", March 1, 2004.
Oil/Vehicle miles: 5,002 / 35,978
Oil added after sample: 1/2 quart

Nothing new to report here. Everything still seems pretty normal from an end-user point of view. The oil has darkened but it's not black yet. A road trip put on some extra highway miles during this interval, which is why it was shorter than usual.

Looks like the TBN leveled off just as it should have -- almost disappointing really, as it leaves us with no exciting and dramatic news to report. Yep, so far this part of the study is class-A boring: Amsoil is hanging in just fine. Viscosity keeps going up, and the LS1 prefers lower viscosity, so that's the only annoying thing right now.

The oil change indicator blipped on at 36,091 miles, which is 5,113 miles into the test. During the Mobil 1 study, the indicator tripped at 5,060 miles, so we must be doing a pretty good job of keeping the test regimen fairly consistent. Oh, and those of you who still change dinosaur juice every 3,000 miles are changing your oil 40% more often than you need to.

Mile 6000 -- Nathaniel Crenshaw, March 18, 2004.
Oil/Vehicle miles: 6,041 / 37,017
Oil added after sample: none

Nothing unusual from drawing this sample. Nor anything unusual in analysis. Everything is remarkably stable. All together now: "It's quiet. Too quiet."

Mile 7000 -- Bryan Savage, April 9, 2004.
Oil/Vehicle miles: 6,992 / 37,968
Oil added after sample: 1/2 quart

Still going just peachy. The lab made note of the lead reading, but it's still not high enough to worry about. TBN continues to drop slightly -- too bad we can't compare it directly to the Mobil 1 numbers, but them's the breaks. Still though, with this sample, TBN is lower than Mobil 1 was at 12,000 miles, so it's possible that Amsoil's play might get shortened by TBN retention. It's too soon to call, but it's the most interesting thing we've got to talk about right now.

Mile 8000 -- Bryan Savage, May 1, 2004.
Oil/Vehicle miles: 8,130 / 39,106
Oil added after sample: none

A road trip caused us to miss our sample by a hair over 100 miles. At this point the oil looks black, like used oil ought to. It also continues to thicken up, and is now officially a 5W40 oil instead of the 5W30 we poured in there. Frankly, this annoys the heck out of us -- if we wanted a 40 weight oil in there, we would have bought a 40 weight oil -- and we would have quit right here, except it's not worth the din of hate mail we'd get. So, we'll see what happens, particularly whether TBN manages to rally, 'cause at the moment it's dropping like an acid eater. Wear, however, continues to be for all practical purposes inconsequential. A good oil, yes, but a long-termer? We'll see.

Mile 9000 -- Bryan Savage, May 30, 2004.
Oil/Vehicle miles: 9,112 / 40,088
Oil added after sample: 1 quart

Finally, it took a while, but here we are at another sample. Not much new to report. Everything's stable at the moment, except for TBN, which continues its spiral downward. The laboratory says 1.9 is still good, but if it doesn't level off soon, then Amsoil will be done in 2000 miles -- even allowing for the 40-weight viscosity. Interesting that Amsoil seems to not display the TBN boost from make-up oil that Mobil 1 exhibited -- or if it is exhibiting the boost, then God help anyone whose engine doesn't use oil! No easy way to know, really, without complicated tests on multiple engines.

Amsoil's rate of wear metal accumulation is clearly superior to Mobil 1 in most cases. From 6,000 miles to 9,000 miles, Mobil 1 went +12ppm iron, +19ppm copper, and +5ppm lead. Over the same interval Amsoil went +4/+4/+5. Both oils are doing about the same for lead, but clearly Amsoil is doing far better in iron and copper. However, some might argue that we need to make allowances for Mobil 1 contending with an engine still breaking in, so if we measure (ferinstance) the 13,000 to 16,000 interval for Mobil 1, we get +3/+2/+6. So, is Amsoil really doing so much better? We shall see whether Amsoil's TBN allows us to see Amsoil's behavior at 13,000 miles as well.

Mile 10,000 -- Bryan Savage, July 22, 2004.
Oil/Vehicle miles: 9,996 / 40,972
Oil added after sample: none

Boy, that wait was sheer torture, eh? But, the sample's out now. Clearly the quart of make-up oil gave Amsoil a bit of a boost: it looks better across the board. We also did a Dexsil TBN test, which showed a TBN of 4.0. And -- shhhhh, it's a secret -- we're still waiting on test results from an alternative laboratory. Looks like we can keep on going for a while.

Mile 11,000 -- Bryan Savage, September 17, 2004.
Oil/Vehicle miles: 11,024 / 42,000
Oil added after sample: 1/2 quart

Too much good weather eating into car-driving time. Well, motorcycle season will be up in a few weeks -- it's already dipping into the 40s overnight -- so mileage on the test car will increase. Still, expect the study to reach its one-year mark around 13,000 miles instead of the 18,000 miles that Mobil 1 saw.

Amsoil continues to impress with its wear metals but the viscosity is really getting out of hand. TBN is back down again as well -- the effects of make-up oil on its longevity are particularly evident in the last few samples. Frankly, with the viscosity/TBN issues, we are suspicious that Amsoil's wear metals are simply a byproduct of an older engine. A re-test with Mobil 1 is probably in order.

Mile 12,000 -- Bryan Savage, October 15, 2004.
Oil/Vehicle miles: 12,046 / 43,022
Oil added after sample: 1/2 quart

It's that time of year you've all been waiting for: when the economy of motorcycling is outweighed by the lack of mercury in the thermometer. Rats! Well, this oil has about another month to go before the one-year mark is up, so we figure the next sample will be the last. So far so good though; Amsoil is holding its own, except for viscosity. We've noted about about a 17% drop in fuel economy and we're curious to see whether we pick that back up with the next brand of oil.

The results continued Amsoil's trend of excellent contamination control -- wear metals are low, insolubles are still under control (remember, by this time Mobil 1 got its oil filter changed from too many insolubles), if only viscosity weren't so high! This stuff, which says 5W30 on the bottle, is now a middle 40 and is oozing its way toward 50! Bad news for engines that prefer thinner oil. Any connection to the fuel economy drop? You'll know as soon as we do.

Mile 13,000 -- Jochen Lellesch, November 5, 2004.
Oil/Vehicle miles: 13,001 / 43,977
Oil added after sample: none

Ah, the second-to-last sample. By rights it should be the absolute last sample, but we're going to spot Amsoil one more after this. At 13,000 miles, Amsoil continues to hold steady -- clearly, Amsoil can last much longer than we initially thought possible. That is provided, of course, that you have no problem with the oil thickening way out of grade (many people don't, which is why we continued the test despite our own reservations about it now being a solid 40-weight oil). Well, one more sample to go, and then we'll enter the next flush period, which should settle whether the oil is contributing to the fuel economy drop.

By the way, we'd like to apologize to Blackstone Laboratories for constantly posting the results late. Blackstone is always diligent about providing results in less than a week from when we mail the sample, but we frequently are too busy farting around with vintage motorcycles or some other project to get the data online right away. Sorry y'all!

Mile 14,000 -- Dick Brewster, December 2, 2004.
Oil/Vehicle miles: 13,994 / 44,970
Oil added after sample: none

This is it. Amsoil is done! The oil exceeded a year in service, with 14,000 miles on the ticker, and no filter change! Well, if the year hadn't ended, we would have had to change the filter now -- it finally reached our insolubles cap, 2,000 miles after Mobil 1. The main thing that stands out on this, our final Amsoil sample, is the ridiculous viscosity. This 5W30 oil has now thickened out to a 15W40 -- argue whether it matters if you like, but we believe engine builders spec an oil for a reason, and this oil is far, far thicker now than intended for the LS1. Switching to our flush Mobil 1 netted a nearly instant 10% improvement in fuel economy, and the engine runs a heckuva lot smoother too. To Amsoil's credit, wear metals remain in check, but we will soon see whether that was really thanks to the oil or just to engine break-in. We'll start posting detailed analysis in the coming weeks.

Next up: is it true that Mobil 1 was handicapped by an engine still breaking in? We find out!

Right now we are going through the Mobil 1 flush. Expect testing to resume around February.

Analysis