Here come the big spenders! I can hear their footsteps.
So let's get some questions answered. What is this vehicle? How much is it worth? How is it used for the few hundred miles driven per year? Is it a Diesel? Do you run an air filter?
IF: It's a Hemi Cuda
It's a particular collectible
The 500 miles per year are spent competing in the Daytona, Indy or Baja 500
The 500 miles are put on 1/8 or 1/4 mile at a time
You drive on country roads without an air filter
It's a Diesel.
THEN: You may want to worry about engine oil
If none of the above statements apply to you, my advice would be to use the oil year after year until you've hit 3,000 miles and then change it, or 5,000 miles for a synthetic. ExxonMobil says Mobil 1 has a shelf life of 5 years. I look at that number as being very conservative.
If you are really curious about the condition of your engine oil on October 1, buy an oil analysis kit and get a sample tested. It used to cost me $18.00. Blackstone Labs will send you a free sample kit and charge you $28.00 for the analysis. What you'll get back is a report that gives the specific of your particular sample, how it fits in the manufacturer's acceptable range, and how much/what kind of particles you have in your oil. You will most likely see that everything about the oil is suitable for continued use. The reports do all the interpreting for you, telling you if the value is good, so-so, or bad.
Maybe you remember my '93Suburban story. It was used more than half time as a delivery vehicle, delivering kids to practice. Occasionally we'd take a long trip. I was using conventional oil and forgot to change the oil after 5,000 miles. I changed it at 12,000 miles and sent in a sample. The analysis report showed that the oil still met specifications after 12,000 miles.
It is a FACT that there are over a million particles larger than 4 microns in every liter of new motor oil. So changing the oil doesn't necessarily mean you are reducing the number of particulates. The largest source of particulates in the oil is road dust. There are also wear particles present. There may be particles from a chemical reaction causing their formation. Acids in motor oils are produced by moisture in the oil. Doing lots of low speed driving or stop and go driving increases the chances of moisture to accumulate in the oil. Not driving does less.
For most automobiles, oil is much less important than we'd think, as long as it is present and meets minimum specs. How can I say that? Think about the causes of engine failure. I don't believe lubricating oil is in the top five of the list. Overheating, head gaskets, detonation, are a few of the causes.
Several years ago Quaker State ran a program where if you used only Quaker State oil and possibly filters in your car, they'd warranty the engine against oil related failure for a lot longer than factory. The reason they could dare to do this is because oil related failures in engines are relatively rare. This excludes running out of oil, of course.s
I know oil is like religion to most of us, but we really should start taking the longer view. That money I saved on an unnecessary oil change will buy dinner and a movie for two. Keep the marriage strong, it can cause you to lose your special car much more certainly than an oil related engine failure!
R.
