Read the label. That’s what I have always had a problem with. Today, I drained my oil for an oil change and went to my stash and found that it was Aeroshell 80 (straight mineral), instead of Aeroshell W80. The thing is, that I had already added 2 quarts of that over the last two weeks to my W80.

What will be the down side to my engine? I went and exchanged what I had for W80, so now that is what’s in the plane again.

While I was at the distributer, I saw 100 Plus, 100, and W100. How confusing. The employees don't know what any of them are for, so no help. PG

You didn't hurt a thing. Now if you had flown several hundreds of hours on straight mineral oil I would tell you to stay with straight mineral oil, maybe. Biggest difference is it doesn't have detergent additives that keep the engine clean. I have seen engines that have a lot of hours on them on mineral oil change to detergent oil and the detergent break up the deposits and these deposits clog small oil passages, but running a couple of quarts in a couple of weeks? You didn't hurt a thing. If it makes you feel any better add some Marvel Mystery oil to it, I don't think it's anything but detergent additive and mineral spirits.

From:
http://www.shell.com/home/content/aviation-en/productservice/aeroshelllubricants/pistonengineoils/pistonengineoilsatag_10081016.html

AeroShell Oils 65, 80, 100 and 120
AeroShell (straight mineral) Oils are available in four different viscosity grades (SAE 30, 40, 50 and 60). They are blended from selected high viscosity index base stocks and contain a minimum quantity of additives. These oils are especially appropriate during the break-in period of most new or recently overhauled four-stroke aircraft piston engines.

AeroShell Oils W65, W80, W100 and W120
AeroShell 'W' (ashless dispersant) Oils were the first aviation piston engine lubricants to be formulated with non-metallic dispersant additives. They provide exceptional lubricant performance and avoid the build up of metallic ash residues on critical engine components. These oils are intended for use in a wide range of four-stroke aircraft piston engines, including fuel injected and turbocharged variants.


AeroShell Oil W100 Plus
A new, premium SAE 50 monograde oil that combines proven AeroShell 'W' ashless dispersant technology with advanced anti-wear and anti-corrosion additives. It has been developed for pilots who want a single grade piton engine oil that delivers an extra level of protection and performance.


AeroShell Oil W 15 W 50
This multi-viscosity grade, ashless dispersant pitons engine oil is a unique blend of high quality mineral oil and synthetic hydrocarbon base stocks. Formulated to provide anti-wear and anti-corrosion protection, this oil offers you better lubricant performance from start-up through to high temperature operation. AeroShell W15W50 is considered to be superior to single grade oils in most applications.


AeroShell Oil Diesel 10W-40
AeroShell Oil Diesel 10W-40 is a fully synthetic, multigrade engine oil designed for use in the new generation of compression ignition (Diesel) Aviation Piston Engines. The formulation has been selected to be suitable in piston engines fuelled by Jet A or Jet A-1 and is designed for use in the latest highly rated turbocharged diesel engines under all operating conditions. AeroShell Oil Diesel 10W-40 MUST NOT be used in spark ignition, or Avgas powered aircraft engines.

As a64 said, adding a quart or two of ANY approved aviation oil (even if it had been Exxon Elite or Phillips X/C) won't hurt a thing. All these oils are blended to be compatible with modern aircraft engines.

In future, if you're going to run straight weight oil, use W-100 Plus. It has a much better additive package than the others. 15 W 50 Aeroshell shares that additive package.

Or, run the multi vis all the time. It's a bit more expensive, but it's good stuff.

I use Exxon Elite.

I also add ASL Cam Guard to every oil change, for the additive package that it offers, and isn't offered anywhere else.

MTV

MTV,

Ahh, we meet again, MTV, on yet another forum

Exxon Elite in Alaska with cam guard.
Phillips X/C in Florida with cam guard.

Don't ask about the difference, but both seem to be working fine.

GR

Actually I do have a question about the difference. I went to Elite on the basis of the Aiviation Consumer data, then added CamGuard on the same advice. I had been using AvBlend. Since the Florida cub had X/C put in by WipAir I just added CamGuard.

I can make this observation. The Elite turns dark fast. The X/C stays like new a lot longer. Is it the oil or is it the airplanes. I have always assumed the the Elite was doing it's job by turning dark. Soo, is the X/C not or is the Florida cub running better or cleaner than the Alaska cub?


GR

Used straight weight Shell mineral oil for breakin (30Hrs) Changed oil & filter and went to Phillips 20-50 XC. Did this on several engines (recomended by IA) and have had no problems. Change oil and filter every 30Hrs and inspect the screens/filters for any metal.
I am very diligent about changing oil and filter.
Some people I know use Shell and I see very little difference. When opened up these engines are very clean inside.
When breaking in a new or reground cam I have used a paste (black...don't remeber the name) on the cam during assembly.
I believe using a good oil..no matter the brand (look for codeing on the container) that is designed for your application, keeping it clean, and replacing it are critical to long life.
As far as mixing oils.....ANY lubrication is better than low or no oil!
If you can't get what you need, get as close as you can no matter the brand.
I use Marvel Mystery oil in the gas for upper cylinder lub and lead scavenging but I do not use it in the oil...maybe if I ran in colder temps consistantly I would use it.
HC

highcountry,

I'd amend your statement with one caveat: If you need oil in your aircraft engine, add a quart of any APPROVED AIRCRAFT PISTON ENGINE oil.

DO NOT add a quart of automotive oil to your airplane engine. That's per several well known lubricants experts. Different additive package, different problems (air cooled vs liquid, etc). Don't go there.

There ARE significant differences in additive packages amongst the various aviation oil manufacturers. In my opinion, Exxon Elite has one of the best additive packages, BUT I still add ASL Camguard, because it provides even better anti corrosion protection.

Portage Creek,

I've been told by some pretty smart lubricants guys that the change in color of the engine oil is indicative that the oil is doing its job--ie: removing contaminants from the engine and transporting them to the filter and the oil itself. So, given the SAME ENGINE, I'd say the oil that darkens fastest might indeed be doing its job better. With two different engines, I don't think you can make any sort of assessment, because the engines could be producing contaminants and wear residue completely differently and at different rates.

Nevertheless, the best way to achieve longevity with an aircraft engine is to run it regularly, get it up to operating temperature every time you run it, and change the oil regularly with a good quality aircraft engine oil.

MTV

mtv....I agree..only aviation type oil, that is why I mentioned the codeing of the oil.
ONLY in an absolute emergency would I use anything other than aviation oil.
I am an organic chemist by education and worked in a refinery for 5 years blending fuels and oils so I know a little something about hydrocarbons.
HC