2017 test2 productsEngine Oil & Fluids
Which Motor Oil Brand Wins?
A head-to-head test of 2 motor oil options with the measured results for each. See how they ranked and watch the full test video.
Ranked first
WD-40
Check price on Amazon
Affiliate link. We may earn a commission at no extra cost to you.
The measured results
Every number below is read straight from the test. Scroll sideways to see all measurements. Products are listed in the order they finished.
| Product | Composition (from label/CAS research) | Boiling point | Lubricity tester (bearing spun at 100 RPM under downward force, film-strength wear comparison) | Cold flow test at -15 F | 1-hour engine run test as a full crankcase oil substitute |
|---|---|---|---|---|---|
| 1WD-40 | 45 to 50% LVP aliphatic hydrocarbons; a further aliphatic hydrocarbons component described in the transcript as '20 less than 25%,' which reads as a caption garble and is preserved verbatim rather than corrected; less than 25% petroleum base oil; less than 10% non-hazardous ingredients; 2 to 3% carbon dioxide | 361 to 369 F (183 to 187 C) | the WD-40 test bearing showed noticeably more wear damage than a previously tested 10W-30 motor oil bearing; described qualitatively only, no numeric wear measurement given | WD-40 and 10W-30 were both placed in a freezer to compare flow at that temperature; the transcript shows only the test setup with no spoken numeric or comparative result afterward | engine survived the full hour, including periods under load via an engine brake and with the cooling shroud removed to run hot; cylinder head temperature reached approximately 500 F under load; significant blow-by/smoke observed from the crankcase ventilation tube; WD-40 level in the crankcase dropped from slightly above the top dipstick hash mark to barely touching the dipstick by the end of the test; compression dropped by 5 PSI over the course of the test (chapter marker states an initial compression reading of 110 PSI) |
| 210W-30 motor oil conventional | not tested | not tested | used as the baseline/control bearing from a previous test; showed noticeably less wear damage than the WD-40 bearing | not tested | not tested |
How it was tested
- label/CAS research into WD-40's chemical composition and boiling point range
- lubricity tester: a bearing spun at 100 RPM under applied downward force to compare film-strength wear between WD-40 and 10W-30 motor oil
- cold flow test: WD-40 and 10W-30 both chilled to -15 F to observe flow behavior
- 1-hour running engine test: a small engine's crankcase filled with WD-40 instead of motor oil, run under intermittent load via an engine brake with the cooling shroud removed, monitoring cylinder head temperature, blow-by/smoke, crankcase fluid level, and compression before and after