Short answer
A used-oil analysis reports wear metals, contaminants such as dirt, coolant and fuel, and the oil’s viscosity. Take samples the same way at the same point each time, record the miles or hours on the oil, and read the results as a trend. AMSOIL sells mail-in Oil Analyzers kits for engine oil, drivetrain fluids, coolant and diesel fuel, so you can test from anywhere.
What an engine oil analysis shows
Wear metals such as iron, aluminum and copper point to the parts that are wearing. Silicon often means dirt is getting past the air filter. Sodium and potassium can indicate coolant in the oil. Fuel dilution and viscosity show whether the oil is still the right thickness. Depending on the test, the report may include base number, which tracks remaining additive reserve in diesel and some gasoline oils.
Most labs add a written comment that flags anything abnormal for the engine type and suggests a resample or an inspection.
Choosing an oil analysis kit
The standard Oil Analyzers test kits cover engine oil and drivetrain fluids and differ by how the sample is shipped: postage pre-paid, UPS pre-paid, or non-postage-paid. The value kit is a lower-cost test aimed at one question: does the oil need changing. The all-in-one kit includes a vacuum pump, 25 feet of tubing, three sample bottles and three tests.
The commercial maintenance, drain-interval and failure-analysis kits are for commercial use only. Separate kits test coolant, including freeze and boil points, and diesel fuel for contamination or performance properties.
| Kit | Fluid | Notes |
|---|---|---|
| Oil Analyzers Test Kit (OAIPPKIT, OAIUPPKIT, OAINPPKIT) | Engine oil, drivetrain fluids | Choose by shipping method |
| Oil Sample Value Kit (KIT14) | Engine oil | Lower-cost test of whether the oil needs changing |
| All-In-One Sample Kit (KIT18) | Engine oil, drivetrain fluids | Pump, tubing, three bottles and three tests |
| Commercial kits (KIT15, KIT16, KIT17) | Engine oil, drivetrain fluids | Commercial use only |
| Coolant Testing Kit (OAICOLKIT) | Coolant | Metals, pH, glycol, freeze and boil points |
| Diesel fuel tests (DETESTKIT1, DETESTKIT2) | Diesel fuel | Contamination, or performance properties |
Source: AMSOIL Oil Analyzers Test Kit, Postage Pre-Paid.
Source: AMSOIL OAI All-In-One Sample Kit.
Source: AMSOIL OAI Oil Sample Value Kit.
How to take an oil sample
Sample when the oil is at operating temperature and well mixed, either from the drain stream partway through draining or through the dipstick tube with a vacuum pump. A sample from the bottom of a drain pan or the first slug out of the drain plug is not representative.
Use the same method and timing each time. Fill out the form completely: oil brand and grade, miles or hours on the oil and on the engine, and whether oil was added. Incomplete forms make the lab’s comments less useful.
Source: AMSOIL Oil Analysis Pump.
Reading results as a trend
One report is a snapshot. Two or three samples at similar intervals show whether wear metals and contaminants are steady or climbing, which is what the numbers are for.
Use analysis to catch problems such as a leaking air intake or coolant entering the oil, and to support decisions about drain intervals within the engine maker’s requirements. Diesel owners often track soot and fuel dilution as well. Keep the reports with your service records.
Sources checked . Prices and product guidance may change.
Frequently asked questions
Is there oil analysis near me?
You do not need a local lab. The kits are mail-in: take the sample at home or in the shop, fill out the form and send it to the lab.
How much does oil analysis cost?
AMSOIL lists current kit prices on its site, and they vary by test and shipping option. A1 Synthetic Oil does not list prices.
How often should I test?
At each oil change while you are establishing a baseline, then as often as the decisions you are making require. Trends need at least two or three samples.
Can I test transmission or differential fluid?
Yes. The standard Oil Analyzers test kits list engine oil and drivetrain fluids.
Does oil analysis tell me to extend my oil changes?
It shows the oil’s condition and the engine’s wear. Any interval change still has to meet the engine maker’s requirements.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].
