This is Why I Don't Change My Oil

[twobjshelbys]

Originally Posted by Godabitibi

Here is another way of looking at it.
A friend of mine had a super nice Pantera that he drove only once in a while for small ride in town and park to chat with friends. He would then go back home and park it in the garage until the next little ride.
I asked him once, when did you changed your oil ? And his answer was there is no need it's still like new.
He pulled the dipstick and showed me how clean the oil was. And I told him clean doesn't mean it still good.
Oil oxydize over time when exposed to heat and moisture.
When used only on short rides as he was doing there is no time for moisture to evaporate.
Moisture and and temperature change without high heat help oxydation to get worse and makes a good environment to make acids.

When oil start to become acidic it then start to corrode metal.
Hydrocarbons can also developped bacterias. These bacterias can also make problems in gasoline over time.

That friend not using his car enough had a problem with gas and we had to remove the gas tank. In these cars you have to remove the engine to get the tank out. So we removed the engine.
While at it he said maybe we can have a look at the motor. So I pulled the oil pan to look inside.
When I removed the first bearing cap I spotted a darker spot on the crank journal. I asked him to bring a magnifier to look closer and showed him what the darker spot was.
I showed him it was corrosion pitting in the crank material due to acid in it's NICE LOOKING oil color.

I then told him this is in a place where there is no AIR in contact with the metal, now lets have a look at the top of the motor in the lifter galley where tnere is a lot of AIR IN CONTACT WITH METAL.

The botton of the lifters were SO CORRODED that they were like 80 or 40 grit sandpaper.

Oil change is a CHEAP maintenance. When you drain it you expell a lot of dirt and other chemicals.

This also speaks to the importance of running the engine periodically at full operating temperature. All engines suffer from the 1 mile little old lady trips to the grocery store. That's the reason we change the oil in our Honda at 3000 - 5000 miles.