what is better than "correct"?

[Kit Sullivan]

I am always amused at those ametuers who think they know better than learned engineers and mechanics.

Customers of mine are constantly wanting to put 20W50 in brand new cars designed to use 0W20 or 5W20 motor oil. Thier thinking is always the same: " its too hot for that thin oil...those engineers dont have a clue what they are doing"

A friend of my business partner has a newer Honda Fury motorcycle. It takes 20W50 V-twin oil and requires 93 octane gas.

He has bad engine problems at 13,000 miles, having trouble getting it coveted under warranty.

Turns out he has been using 60-weight AIRCRAFT engine oil, and 100 octane race gas.

When I asked him why he uses that stuff, he says "because its better, obviously!".

I shake my head at chuckleheads like this...

 

[c9zx]

OMG! Too funny. I'll bet he is at least a part owner of an aircraft. Chuck

 

[MechEng]

My oh my. I've gotten in a number of arguments with people about how 93 octane gas isn't actually "better" than 87 octane gas. But then trying to explain to them what octane rating really is doesn't normally work.

 

[Luke]

Ha I learnt this lesson as a kid I put avgas in my old 2stroke dirt bike then thought if that's good methanol is better. WRONG.

 

[1972MustangSVH]

Octane "ratings" are a joke, and the jokes on us.

Get one of these and see how appalling those octane "ratings" posted on the pump really are.

http://www.shatox.com/octanemeter.html

From the aircraft engine perspective I know this:

- Car gas is a airplane mechanics best friend.

- Despite all the studies, reports, and expert testimony, experience from the field tells me that it's so octane inconsistent and full of different additives that you:

Will not:

-be able to form optimal leaning habits because you'll always be trying to "out guess" the gas.

-be able to "as accurately" predict a carburetor icing event.

-be assured that your fuel is always "alcohol free."

You will:

- experience sticking rings and valves due to the "coking" of the additives.

- see higher oil consumption sooner than expected before TBO.

- at times have to back off rated HP settings to avoid detonation.

- experience higher rates of valve and seat erosion.

- have to replace at least one if not more cylinders before TBO.

You may:

- see extended wrist pin wear due to minor detonation

- experience detonation at different power settings with fuel from different stations.

- experience a cracked piston due to detonation.

Note: Pinging in an automotive engine is an annoyance. Detonation

in an aircraft engine is damaging and dangerous.

With that said: If we minded the fuel that goes in our cars as much as we do the fuel that goes in our planes it would be a different world.