VAF Forums

VAF Forums (
-   Traditional Aircraft Engines (
-   -   Best multi grade (or any grade) oil Brand (

gmcjetpilot 01-10-2006 07:53 PM

Best multi grade (or any grade) oil Brand
Taking a pole on oil brands (PLEASE POST WHY IF YOU HAVE A REASON, besides its what I can steal from my hanger mate. :rolleyes: )

Assuming a normally aspirated Lycoming (I)O-320 or (I)O-360.

Option 1: Phillips X/C 20w-50 ($31 a 12 pak case)
Option 2: Exxon Elite 20w50 at ($50 a 12 pak case)
Option 3: Aeroshell 15w50 at ($55 a 12 pak case)
Option 4: Aeroshell Single grade ($37 a 12 pak case)
Option 5: Other Brand

I personally have great experience with the Phillips X/C and the price ain't bad.

On another list the topic of corrosion resistance (for a plane doing hanger queen duty) is better with the other brands. That may be true, but I think flying regularly is better than any oil. G

tacchi88 01-10-2006 09:18 PM

Multi grade
I've used Chevron multi av oil, Phillps and Shell. Of the 3 Shell stands out. Can't really say that the other two were worse, but the fact that they turned black earlier than the Shell led me to believe that both had lower flash points. The Shell averaged 1 to 2 hours per qt. more. All three fared better than the straight weight, the Shell being the better of the three. Price isn't an issue either.

TShort 01-10-2006 09:18 PM

I'm currently using the Aeroshell 15w50 in both the skyhawk and the 170 ... have had great results so far. No experience with anything else, and as long as things go well I don't guess I'll switch. I buy it in the gallons and it is a little cheaper...
My A&P buddy that flies a C-140 and an RV-6 with O-320 uses the phillips XC and loves it...

-8 wings

osxuser 01-10-2006 10:16 PM

We use single grade (100W) aeroshell in the Cardinal (O-360A1A). But for the multigrades, I'd go with the Philip's because of the price. Honestly, if you fly it once a week, it doesn't matter which you use, so just go with the cheapest. Thats our rational for the single grade.

RV8RIVETER 01-11-2006 01:41 AM

No expert experience to offer here, but thought I would copy the two articles from Aviation Consumer Magazine for information. The first article is oil wear test (OCT 2002) and the second is oil vs corrosion tests (NOV 2002).


In our estimation, Shell?s W100Plus and 15W50 demonstrate better anti-wear performance than the other oils. Understandably, Phillips X/C and Shell?s W100 both failed our anti-wear tests when the testing pressures exceeded those typically found in GA engines. But these oils have no anti-wear additives so this wasn?t especially surprising.

What was interesting was that Elite didn?t do much better and it too failed, even though it contains what Exxon claims is a sophisticated anti-wear package.

Shell?s W100Plus, 15W50 and Elite all meet Lycoming?s AD80-0403 and contain a Lycoming approved anti-scuff additive similar to Lyc?s part LW 16702. However, in achieving this level of anti-wear performance, Shell?s W100Plus and 15W50 oil may have a weakness in that their specific phosphate ester anti-wear additive is not hydrolytically stable. That means that it decomposes in the presence of water. The decomposition products are corrosive and tend to attack soft metals such as copper, lead and tin.

To some extent, this accounts for the copper leaching problem Shell has faced in years past with these oils and which has been reported in the field. Shell told us they have since added an additional copper passivator to combat this problem and we?ve noted that field oil analysis supports Shell?s claims.

Maintaining proper oil temps (above 210 degrees F) as well as frequent oil changes may minimize any corrosion problems that the phosphate ester anti-wear additive may introduce.

Even though Elite didn?t fare well when compared to Shell?s products in our lab wear testing, in the real world of infrequent oil changes and short flights, Elite may still be a good choice because it has impressive anti-corrosion characteristics, which we will be reporting on in a future issue. Further, it doesn?t have the type of phosphate esters found in Shell, thus it has no moisture degradation problems.

So, which would we use in our engine? It depends. If the airplane is flown regularly on long flights and the oil was changed frequently, we would choose either Shell W100Plus or 15W50 semi-synthetic. It has the best anti-wear characteristics, possibly at the expense of some moisture sensitivity. But frequent oil changes can address that shortcoming.

If we only flew around the patch every month or two and only changed the oil every six months or so, then Elite would be an attractive choice, even though it?s not as impressive as Shell from the anti-wear point of view.


Test Results
Our tests showed that Shell?s 15W50 and Elite were statistically equal in corrosion protection, even though Shell looks a bit better on the chart. Both did significantly better than Phillips X/C, which is a good representative mineral-type engine oil.

AeroShell W100 Plus, supposedly with the same anti-corrosion package as 15W50, didn?t perform nearly as well as its semi-synthetic counterpart, a bit of a surprise we weren?t able to explain. (Neither could Shell when we contacted them to ask.) To a degree, judging corrosion protection is subjective but it?s also hard to miss which oils work well and which don?t. This is done simply by judging what percentage of the panels appear corroded over what time frame. The benchmark we used for the chart above was 50 percent corrosion coverage. In other words, how long did the oil protect against that amount of corrosion?

The clear winners were Shell?s 15W50 at 22 days followed closely by Elite at 21 days. At the low end of the spectrum was Phillips X/C at 16 days and Shell?s W100Plus at 18 days. Off-the-shelf additives such as Avblend and Microlon didn?t help, according to our tests. The Xtend super additive that Kollin tested (called variously ASL-2000 or GA2000 in the tests) drove anti-corrosion performance off the charts.

For all practical purposes, Elite and Shell?s 20W50 finished in a dead heat. They both seem effective at corrosion prevention and the fact that AeroShell protected for a day longer is statistically insignificant. One thing we feel confident about, however, is discounting the notion that straight-weight oils protect better than multi-weights. The lab data doesn?t bear this out. We think corrosion protection depends more on the additive package than the weight of the oil.

Exxon?s Exceptions
As noted in the accompanying article on page 7, Exxon has challenged our test results, both for anti-wear and anti-corrosion. First, let?s examine the anti-corrosion issue. Exxon argues that our testing wasn?t done in a lab environment and that hydrochloric acid isn?t a combustion by-product.

We argue that engines don?t exist in lab environments, they live on ramps and in hangars, exposed to wide variations in temperature and humidity. Further, the well-published Exxon tests, in our view, unrealistically use only humidity and the company?s graphs don?t show a time scale.

As for hydrochloric acid, Exxon says that carbonic, nitrous, nitric, and sulfuric acids can be found in engine oil, yet they didn?t use these acids in their testing. Our view is that Exxon relied on a test that?s a reference test, not one that correlates to aircraft in the field.

Our test was repeated with two different acid concentrations (.19 and .93 percent) and both gave the same directional results, with both semi-synthetic oils providing better protection than the unadditized oils. Further, hydrochloric acid, along with hydrobromic acid (from ethylene dichloride and ethylene dibromide lead scavengers used in leaded fuel) and acetic acid are used in the recently designed Ball Rust Test (BRT) for the American Petroleum Institute certification of passenger car oils. Passenger cars currently use unleaded gasoline and yet the API certification test still uses hydrochloric acid to increase the severity of the test.

On the anti-wear side, we take exception to Exxon?s characterization of our tests as like ?Tiger Woods playing bridge.? In our view and that of our expert, Ed Kollin, the tests are more akin to Bobby Riggs playing tennis. Exxon claims that the Falex pin test is normally used to evaluate heavy gear oils. That?s true if the normal protocol is followed, but we reduced the pin pressures significantly to simulate more closely engine conditions, as we explained in great detail when we forwarded our results to Exxon. These pressures were dramatically lower than those used for standard extreme pressure (EP) lube tests.

Nor did we pull the test protocol out of thin air. We selected this test based on a paper published by Phillips, thus we believe it?s a legitimate, fair test of anti-wear properties on an accelerated basis. In our view, the fact that Exxon Elite either failed?twice in our tests?or had higher wear rates in Exxon?s own tests, suggests that its anti-wear package could be improved or is more suitable for an EP environment.

As we stated in the previous article in this series, any of the oils tested are suitable for use in aircraft engines. We can?t honestly say that any of them are substandard or that any should be avoided.

However, we remain impressed with AeroShell?s 15W50 multi-grade. It appears to us to be a good all-climate oil with excellent anti-wear properties and anti-corrosion properties. For anti-corrosion alone, Elite is essentially identical to AeroShell 15W50. If you prefer straight-weight oils?and we can?t make an argument for them?Shell?s W100Plus has good additives, too, although this oil didn?t do as well on the anti-corrosion front.

Exxon did well in the anti-corrosion testing but, in our view, was far less impressive than AeroShell 15W50 in anti-wear protection. We?re somewhat disappointed with Elite, in truth. We think Exxon had a good opportunity to deliver a new, high-tech oil with an advanced additive package but it appears to us as if it hasn?t done that yet. (Are you listening Exxon R&D?)

Performance wise, Phillips X/C is an also ran, in our estimation. It?s not exceptional in either anti-wear or anti-corrosion properties, according to our tests, but our expert, Ed Kollin, says it has an exceptionally good basestock. Could additives improve it? We think so. But the right additives have to be used. In next month?s issue, we?ll look at how some of the more common additives affect the performance of oils

hevansrv7a 01-11-2006 04:14 AM

Corrosion Prevention is a Major Oil Function
This product, not an oil but a moisture fighter, is an additional approach for corrision prevention.
As he says, no water = no rust.
I've just bought one for the C-150 and one for the Superior that will go in my -7A, maybe today.

Steve 01-11-2006 07:03 AM

I originally used AeroShell; 80 in the winter, 100 in the summer and straight mineral when I changed out cylinders, which seemed to occur regularly when I first bought my TriPacer back in '95. All of which meant I needed to keep 3 grades of oil on hand. The Phillips rep at OSH 2000 gave me the sales pitch on Phillps XC. You can use it from break-in to overhaul year-round. That did it. I've used XC ever since. Same price as AeroShell and oil consumtion improved to 7 hrs/qt (was -6). Coincidentally, I never replaced cylinders after

Not a paid endorsement,

Ironflight 01-11-2006 07:50 AM

Good Topic...
This a good topic Geaorge, but in all fairness and good conscience, there is no way I could vote. I think you'd have to be a fleet operator to make a meaningful input on this, becasue individual owners are going to have statistically meaningless experience on which to make a choice. The question "which oil do you prefer?" would be better, with a follow-up of "why?"

In my case, I ran Aeroshell W100 in my Grumman for 23 years, because with the original engine - which was practically run-out when I bought it - I was using a quart in four hours, and saw little point in running expensive multi-vis thought it. When I put a fresh big engine on it, I was familiar with Aeroshell, and kept running it. That second engine burned about a quart in 12 hours, and ran so well that I saw no reason to change anything! I never felt the need for multi-vis becasue I'm down here in Texas where it doesn't get cold enough to make a differnence.

Now with my RV, and it's brand new Mattituck TMX-360, I am running Exxon Elite for the simple reason that Mattituck/Exxon gave me a couple of cases free with the engine! ( marketing move, becasue I have since bought two more cases - I am kind of supersticious about changing what works!). I am trying to decide if I'm going to switch back to Aeroshell becasue it is more readily available right here (My buddy who owns our row of hanagrs buys it by the closet-full, since he's an IA), or stick with the Exxon because that is what I started with. And if I do go back to Aeroshell, do I go back to straight weight?

All these questions I was trying to ignore.....This should probably be in the "Never ending debates" forum by the way! ;)


gmcjetpilot 01-11-2006 04:07 PM

Fair enough

Originally Posted by Ironflight
This a good topic Geaorge, but in all fairness and good conscience, there is no way I could vote. I think you'd have to be a fleet operator to make a meaningful input on this, because individual owners are going to have statistically meaningless experience on which to make a choice. The question "which oil do you prefer?" would be better, with a follow-up of "why?"Paul

Fair enough. I think folks are posting why, and I agree that is more interesting than the statistics. However I do meaningless stuff all the time. :D

I would say the raw poll vote would show, in theory if a proper sample is taken, who uses what, not what is better. A tally of what is most popular is interesting to me, but I agree with your hypothesis the poll is not real useful. It is however a launch for discussion; SEE I got you to make a comment. it worked. :D George

ON THE TOPIC. I talked to Philips Tech guy today and I was mistaken that X/C was a semi synthetic, it is not. It is a multi grade ashless dispersant mineral base stock oil, with no "synthetic oils" added. Here are some facts and truths of all oils (Semi Synthetic or not):

All oils start with a base stock of miniral oils (pure synthetics don't work well in planes, Google Mobile One, synthetic oils airplanes, etc....) See last item.

All oils have additives, some more than others. The ones advertised as MINIRAL oil have the least, used for break in often. The multi grade and ashless dispersant oils have more additives. The synthetic blends (Exxon Elite and Aeroshell 15w50) have the most added to the base.

For planes the fly often corrosion is not and issue, regardless of the oil.

The oil industry itself is in a debate about how effective corrosion protection from low low use aircraft engines are. The industry test may not represent the real case inside an engine. There are additives that help corrosion prevention but there may be un-intended consequences or trade offs by adding these anti corrosion additives.

One function of aircraft oils it to hold in suspension the junk that aircooled aircraft engines make using leaded fuel. The byproduct of combustion (salts) and wear materials need to be held till drained with out leaving deposits (thus the ash-LESS dispersant part). Synthetic oils do not do this well, but do have good antiwear properties. So there's a trade off with blends. You have less miniral base stock to hold junk, but the wear qualities are better, at least in a laboratory in a controlled test. I think if you fly a lot and change your oil every 25 hours, give or take, with a new filter, you'll be as good or better with a basic oils, than if you used a synthetic oil blend and flew infrequently and changed oil less. Clearly your getting something for your $12-$14 premium price for the blended stuff. From the poll it appears that people agree the price premium is with it.

Whether the extra money is worth it is what I am kind of looking to gauge by the poll. So far it seems the group is pretty savvy consumers and are not totally swayed by pretty bottle colors, lab test and sponsored arco teams at the airshows, although I love the free-be stickers, patches and posters. I think Philips does much less advertising and thus may be better bargain. However $14 is like nickles in aviation money. Clearly the Aeroshell and the Exxon Elite (I got a free case also) have something different to offer over a pure (or purer) miniral based only oil. Is it worth it? LET THE POLL CONTINUE!! :eek:


robertahegy 01-11-2006 04:15 PM

I broke in my new 0-360 A1A with Aeroshell Oil 80 for 50 hrs . I changed the oil and filter after one hour of ground run, before 1st flight. I then changed it at 25 hrs and 50 hrs, with new filters. After break in, I switched to Aeroshell 15W50. I use about a quart in 20 hrs.


All times are GMT -6. The time now is 12:35 PM.