[Ventmaster]

For years (and I'm talking since a long time ago) I could only afford fast motorcycles. Aluminum engines with steel sleeves in the cylinders and rods, etc.. IOW, multiple alloys throughout. Besides, cars sucked in the 80's! Had a 1986 Z-28 with V-8 and 4 BBL carb with 5spd trans. and it was rated at 180hp net. Jeez!

The conventional wisdom was at the end of riding season, no matter how few miles since last oil change, you put in fresh oil. Combustion causes not just condensation, but also acids that can have adverse effects if left standing in the motor. You also were advised to add Stabil to the gas and run enuff thru the fuel system to protect it during the winter (now they have Stabil with ethanol protection) and top off the fuel tank to prevent rust as gas is hydrophilic and will draw water and you didn't want the tank to rust. These days the tanks are plastic on automobiles, but I do use Stabil if mine's ever sitting a long while.
And those truly conscientious of us (OK- anal), would pull the spark plugs out of each cylinder and shoot 5ml of oil into each cylinder and turn the motor over a few times (not start it) to protect the cylinder walls before returning the plugs to keep crap out.

My SS is a 2017 has less than 15Kmiles (so less than 3K per year) and I couldn't tell you how many times I've changed the oil (myself to make sure it's done right- Just spoke to a lady today that had her's done at the Quicky Lube on the corner and 5 days later it threw a rod and crankcase was dry.) The "tech" had put the oil plug in finger tight and unfortunately her "low oil" light failed.

I'm old enuff to know I won't keep this car forever. (Remember when you thought that about a car?) But by God I'll care for her til the day she leaves.
You should too cause these are great cars.

[NashZL1]

I get an oil change in my 17 Corvette Grand Sport when the OLM gets to 10% or less, which is at about 11 months. Car was purchased new and has 20,000 miles now. Had it done last week. Will do same for my new ZL1 after the second oil change at 1,500. Just did the 500 mile change at the dealer last week also. Want to protect the warranty on the new one and the extended warranty on the Corvette.

Our others, 7,000 miles or one year. My old 1971 Datsun 240Z, which gets driven about 1,500 miles per year, still gets an annual oil change. Same for my 1995 Nissan 300ZX Twin Turbo.

I'm sure an oil analysis would say it's ok to go further, but...

Got to take care of your stuff, and the expense is not that great.

[ctrlz]

Originally Posted by Weege

So I'm looking for a mechanical/engineering reason for low mileage oil changing. The legal incentive is about to expire.

As expected, you get a lot of "better safe than sorry" and "it's so cheap, why not?" arguments.

I have an undergraduate degree in chemistry and the below article, quite frankly, exceeded my expectations! Dig in!
https://www.machinerylubrication.com.../oil-breakdown

For oil just sitting there, oxidation would be the main breakdown route. But even with intermittent running, you will get interaction with the other routes like thermal and compressive.

[Weege]

The snow and salt are gone for now, so just waiting for temperatures to get out of the 40's. Instead of driving I continue to over think this topic of changing low mileage oil that's been sitting in a cold engine for 6 months. This thread convinced me to change the oil due to potentially harmful condensation and breakdown products. Now my overthinking raises this question: I have to warm the engine to drain the oil. Should I just run the engine enough to warm the oil and avoid running it further, or is there any reason to get it to full operating temperature to burn off water/toxins I'm about to drain anyway? I'm guessing there's no point to the latter.

[ctrlz]

Originally Posted by Weege

Now my overthinking raises this question: I have to warm the engine to drain the oil.

You are a world-class overthinker.

I drive my car around the block to get the oil slightly warm before I do a change. I don't like burning myself with hot oil or messing with a hot oil filter. Takes a little longer to drain, but I'm OK with that.

[Rayvan]

Originally Posted by Weege

My 5 year warranty will be up by the time I get on the road in Spring. So I'm looking for a mechanical/engineering reason for low mileage oil changing. The legal incentive is about to expire.

You should change it, but also send in a sample to the folks at Blackstone Labs. They'll let you know exactly how good your oil is, and they usually recommend realistically how far you should go.

In my case, after a year I'd only driven the car 3,300 miles, inc. 3 track-days. Blackstone said that my base number was still at 6, and I could easily extend my interval (I won't until my 5 yr. mark, BTW), but it still shows how good the oil is that we're throwing away.

This is Blackstones opinion on my 1 yr. old oil. FWIW, I paid extra to get the Total Base Number:

"This engine looks good in its first round of testing. The wear metals are all in good shape compared to the universal averages, which are based on about 3,900-mile oil change intervals for this engine type. This oil run was a little shorter, but you also have three track days on the oil, so we're impressed that metals tested as well as they did. No contamination from fuel dilution, water, or coolant was found, and the TBN tested well at 6.0 since 1.0 or less is considered low. Nice!"

If I get reports like this after my warranty expires, I'll be extending my intervals until that TBN is closer to around 2, or 3.