Is Oil Analysis Worthwhile? - Toyota Parts Blog

Oil analysis is a popular discussion topic on automotive forums. Vehicle owners share their oil analysis reports, declaring that “brand X” is the best oil on the market based on testing. Others argue that regular oil testing is essential, because oil analysis is the only way to really understand what’s going on inside a vehicle’s engine (or so they say).

Oil Analysis Worth It?

Engine oil testing and analysis can tell you a lot about what’s going on inside your engine…but it’s also time-consuming and costly.

It’s true -engine oil testing and analysis can tell you a lot about what’s going on inside your engine. But it’s also time-consuming and costly. Is it worth doing?

First, Let’s Talk About How To Test Your Oil

Collecting oil to test is straightforward enough. Most labs need at least three ounces of oil to conduct a complete analysis. You can retrieve the sample during your next DIY oil change, or siphon it from your dipstick tube using a simple kit.

Once you have the sample, you can hire a lab to test and analyze the oil, or use a DIY testing kit.

Professional oil testing

Photo Credit: USGS

A standard oil test will include:

  1. Measuring the viscosity of the sample
  2. Conducting spectral testing to measure contaminants
  3. “Flashing” a sample to determine fuel contamination
  4. Measuring for contaminants using a centrifuge

Option #1 – Professional Analysis of Your Oil

With a professional testing service, all you have to do is package your oil sample and mail it off. Most labs promise results within 24 hours of receiving the sample, with a cost of roughly $50 per test (including shipping). Some labs offer bulk discounts that can get the price down to less than $20 per test.

The advantages in having your oil tested by a professional service are accuracy, data, and professional advice. A service like Blackstone Labs will often offer guidance if/when there’s an issue with the sample.

DIY Oil Analysis

While not as sophisticated as a professional oil test, a DIY oil testing kit can help you determine if your oil needs to be changed now (or very soon). See for more info about this kit.

Option #2 – DIY Oil Analysis

If you enjoy maintaining your vehicle yourself, DIY oil analysis might be appealing. An at-home oil analysis kit typically costs less than $30, and most are straightforward. You usually drop warm motor oil onto sheets that come with your testing kit. These sheets will reveal a pattern of colored concentric rings that you can then compare with a provided chart to get your testing results.

A major benefit of doing your own oil analysis is cost and time – it’s a bit cheaper than pro testing, and you don’t have to wait for your sample. However, home testing is no substitute for the data that a professional test can reveal.

What Can You Learn From An Oil Analysis Report?

Essentially, oil testing and analysis will tell you about a) contaminants and b) oil break-down. This means oil analysis can help you:

  • Determine how efficiently your engine is burning gasoline
  • Determine if your engine oil is deteriorating faster or slower than expected
  • Determine if your oil has excessive contamination from water, dust and dirt particles, metals, engine coolant, etc.

The data from this test can help you discover previously unknown problems, like a slowly deteriorating head gasket or excess bearing wear. The data can also help you determine if you should increase your oil change frequency. Testing can even tell you if your engine is nearing the end of it’s life, helping you get rid of your vehicle before it causes a major expense.

Sample oil analysis report.

This sample oil analysis report shows what metals may be in your sample, how your current sample compares to previous samples, how much fuel or water is contaminating your oil, and — most importantly — offers commentary on what might be going wrong with your engine. Image courtesy Blackstone Labs.

Another popular benefit of oil analysis is that it can help you figure out the best oil change interval for your vehicle. You can measure oil breakdown and contamination over time, and then use this info to figure out the ideal mileage or time between oil changes.

Can Oil Analysis Be Used To Compare Motor Oil?

If you’re hoping to use oil analysis to figure out which brand of oil is best for your vehicle, you’re wasting time and money. Using oil analysis to measure “brand x” and compare it to “brand y” is generally a fool’s errand, unless you make this comparison with dozens or hundreds of tests. Here’s why:

  1. Oil test results will change with the weather, the amount of dust in the air, the type of fuel you’re burning, etc.
  2. If we take two oil samples from two drive cycles completed outside a lab, it’s almost certain our oil analysis results will be different. This is because no two drive cycles are alike, at least not in the real world.
  3. Even if you make a concerted effort to drive your car precisely the same way during both of your oil tests, the weather won’t co-operate. Changes in ambient temperature and humidity levels will affect your oil analysis reports.

Basically, any oil comparison you try to conduct using your personal vehicle is tainted. The only way to accurately test oil is in a laboratory.

Put another way, amateur oil comparisons conducted by consumers driving their vehicles on public roads are pretty much worthless. If you’re hoping to use oil analysis to “find the perfect oil,” or compare one brand against another, it’s not worth your time.

NOTE: The good news is that the SAE (Society of Automotive Engineers) and API (American Petroleum Institute) test oil all the time. If a container of motor oil bears the API “starburst and donut,” and meets your vehicle manufacturer’s recommended SAE standard, it’s adequate for use in your vehicle.

Is Oil Analysis Worth It?

If you’re a racer, engine builder, tuner, or someone operating an engine with a lot of miles, oil analysis is a godsend. If you’re interested in oil analysis so you keep tabs on the condition of your engine – and you don’t mind the time and expense – there’s no downside to testing. It could even save you some trouble.

However, oil analysis is completely unnecessary for most drivers. A single oil test here and there is all but pointless, as oil testing isn’t going to tell you much unless it’s consistent. Consistent testing can help you monitor engine wear and condition, but that’s only valuable if engine wear is a serious concern (because you’re towing, racing, driving an engine with 250k miles, etc.).

Don’t get us wrong: If you suspect a problem with your engine, oil testing can be helpful in verifying the problem. But a single random test done for no reason isn’t going to be helpful, at least not beyond bragging about your favorite brand of oil on some forum somewhere.

Special thanks to Blackstone Labs for letting us use their sample report for our article. If you’re looking for an oil testing company, check them out.

Written by Jason Lancaster