It is best to rely on oil analysis to determine your oil change interval. Of course, on many passenger car vehicles that only take 4-6 quarts of motor oil, the price of the oil analysis can be nearly as much as a complete oil change.

So, for some, the best thing is to execute a “Poor Man’s Oil Analysis”. It is not likely to provide information as accurate and precise as those derived from an oil analysis lab, but it can give you a pretty decent notion of just how effectively your engine oil is handling the extremes within your engine.

In the next few paragraphs you’ll find detailed instructions for one of six DIY oil analysis tests that you can use to establish the condition of your oil and whether it’s ready for a change.

You might also want to consider learning a bit more about oils and filters in general. You might find the following sites useful in this quest.

- The Motor Oil Bible – tons of motor oil information

- The Motor Oil Evaluator – motor oil comparison specifications

- A Motor Oil Forum for discussion of motor oils

The Spot Test

Putting this simple test into practice can unveil a plethora of possible oil degredation issues that might lead to the necessity for draining of the oil: build-up of condensation, contamination with anti-freeze, high particulate levels, dispersant additive deterioration, fuel in your oil, products of oxidation and sludge build-up.

You want to place a drop of used oil on the surface of chromatography paper (good heavy white card stock works pretty well too) – make sure the engine/oil is WARM (not HOT). Place your white paper/card suspended horizontally above a table or countertop and so that the oil drop area will be touching nothing – on either side of the card. For instance, if you’re using stiff card stock or a stiff business card (which you really should be) you could lay two pencils down on a table (parallel to each other) and set the card with each end sitting on one of the pencils.

Wait until the oil drop is no longer moist. Use the list below to evaluate the condition of your oil based on the DRY oil spot.

- A colorless circle or slight yellowish outer ring = “good” oil.

- A dense, dark deposit zone = Dispersant additive failure

- A black, pasty area = Anti-freeze in your motor oil

- Center of circle dark with distinct outside ring = Severe oxidation

- A dark center with surrounding rings = Fuel in oil, Fuel dilution

Information for this test featured in: Fitch, J.C., “The Lubrication Field Test and Inspection Guide”, Noria Corporation 2000

There is a point at which a vehicle owner discovers that not all types and brands of oil are of equal quality. It is at that point that the individual decides that there is a “perfect oil” out there for their vehicle and they begin the quest to find it. So, it seems rather important to determine just HOW to find that “perfect oil”. This article and the follow-up articles I’ll be writing soon will be focused on that particular goal.

Magical Motor Oil Utopia

Of course, many people assume as they pursue their “ultimate motor oil” that there is necessarily a “best oil” that will fit everyone’s needs. Some SUPER oil that will serve everyone perfectly. But, the extraordinary engine oil paradise that they are looking for is a legend at best. It simply doesn’t exist|cannot be found.

It really is not at all possible for a single oil to meet the needs of all applications. I’m sure that’s probably obvious to most. But, it is also not possible for a single BRAND of motor oil to perfectly fit the needs of every user. For instance, although a premium synthetic motor oil like AMSOIL, Redline or NEO may be of higher quality than most, that does NOT make any of them the ultimate choice for all users.

Thus, you’ll need to carefully consider your situation and application and what motor oil characteristics will prove to be most useful to your particular needs (such as low temperature or high temperature operation, long oil drains, low internal friction for improved fuel economy, better wear protection, low volatility, etc.). Once these characteristics have been established, then begin looking for the oils that best offer those lubrication qualities.

If you don’t follow a similar research pattern, it is really not possible to make a truly educated decision with regards to proper oil selection for your application. And, thus, you will likely end up with a lubricant that is not meeting your needs in the best way possible.

Petroleum, blend or synthetic, 5w30 vs 5w40, Redline, AMSOIL or Valvoline, API CI-4 or CJ-4, the list goes on. Which of these you choose, ultimately, makes no difference, so long as those choices will be ones that best serve the needs of YOUR application.