Oil

While the world of piston general aviation wrings its collective hands over an unleaded replacement for 100LL, the turbine market is caught up in a vast, breaking wave of biofuel activity. Even though heavily subsidized biodiesel is already finding a niche market, it looks like demand from the airlines, but especially from the military, is driving an explosion of so-called advanced biofuels development. As we reported in the December 2010 issue of Aviation Consumer, the ASTM approvals for bio-derived turbine fuels are already in place or soon will be.

When an engine tanks prematurely, the recriminations begin. Did the shop screw up the overhaul? Was it bad cylinders? Or could it have been the oil you used? Yeah, maybe thats it…if only youd used Exxon Elite instead of Aeroshell, you wouldnt be looking at a mid-time overhaul. This is the sort of fear, uncertainty and doubt that advertising is meant to mine. And the copywriters are good at it. Elite, for instance, is touted as offering a two-fold increase in rust protection over the nearest competitor. Aeroshells popular 15W50 “helps engines start faster and eliminates need for seasonal oil changes.” BP is marketing Castrols aviation oil and not just claiming its the best, but offering to prove it with lab tests showing Castrol Aviator passed rust and engine deposit trials while its competitors failed. Whats going on here? Are the oil companies lying or just stretching the truth? In our view, its more the latter than the former-the engine oil ads make claims that are demonstrably true, but they make no effort to place these claims in context. The oil companies are happy having you make buying decisions in their favor with little grasp of the larger picture of oil performance.

But our tests show that results vary widely from lab to lab. One techs highly suspect sample may be anothers perfectly normal. Its the trends that count.

But our tests show that results vary widely from lab to lab. One techs highly suspect sample may be anothers perfectly normal. Its the trends that count.

If you have a wet vacuum pump, you’ll need one but otherwise, tune up the breather system first. Of the two major brands, our pick is the Airwolf.

There’s more information than ever about aircraft engine oils but still more heat than light. Heres what the people who make the stuff have to say.

[IMGCAP(1)]Think about it: 40 times a second, an aircraft piston rockets to the top of the cylinder, stops dead in a couple of nanoseconds, reverses direction and plummets to the bottom of the jug, all the while trying to stretch the connecting rod like a piece of warm taffy and exerting enough smash on the bearings to reduce them to oily Babbitt pulp.

Or maybe its better not to think about it. Which is precisely why it makes sense to send oil samples to an analytical lab and have them look for signs of impending doom. Oil analysis has been available in the GA piston-engine market for years and there are plenty of labs to pick from.

But pick one you must. With that in mind, we decide…

by Mike Busch

As a long-time fan of both Aviation Consumer and Greg Travis, I must tell you I am simply disappointed with Travis article The Oil Argument in the December issue.

In my view, its a one-sided treatment that preaches The Company Line of the Shell and Chevron marketing mouthpieces-who have a major stake in the outcome-while dismissing the collective wisdom from the field overhaul shops and owner associations.

For example, the article dwells on the TCM cylinder problems, which are completely unrelated to the choice of oil. It also dwells on the lubricity issue, which is largely irrelevant because our slow-turning loose-tolerance aircraft engines have such minimal…

What is it about oil that makes people crazy?

Historians looking back on the 20th century will probably point to oil, and its effects, as defining our era. So it is in aviation as in the rest of society. Owners, engine shops and manufacturers seem unable to agree on the best oil to use in aircraft engines.

Lately, the debate has focused on so-called straight-weight (often erroneously referred to simply as mineral) oils versus the newer multi-weight oils.

Ten years ago, everyone seemed to agree that the higher-priced multi-weights were better. Today, there’s growing sentiment that cheaper straight-weight oils may indeed be the better choice, especially from a corrosion c…

[IMGCAP(1)]Just as the dropped slice of bread inevitably lands buttered-side down, when you put a quart of oil into your engine, you’ll probably get a few drops-maybe much more than a few drops-where you don’t want them and the rest inside the crankcase, where it belongs.

Weve seen pilots and mechanics use all sorts of funnels, plastic gadgets and harsh invective while doing the dirty deed, so we asked around to see if there are any failsafe secrets on adding a quart or two of oil.

Mechanics tend to use tricks useful only in the shop-mainly large plastic funnels complete with a drain bucket or pan-so we asked pilots what they expected from a good spout, listened to their recommendat…

[IMGCAP(1)]Does the oil you dump into your engine really matter that much? Some owners swear Aeroshell is the best oil going while others wont touch the stuff, preferring Phillips well-regarded XC.

Lacking any valid side-by-side wear data across a range of engine types, no one can really say which is best, although some engine shops are willing to try. Our view is that the way an engine is operated probably has more to do with engine longevity than the type of oil used.

And like most owners, weve tended to assume that the aircraft engine oil market is far too small to justify serious research into improved products.

We assumed wrong. Last spring, oil giant ExxonMobil announced…