2020 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.
Some figures on this page were transcribed from the test video and have not been independently re-verified. Treat the numbers as a close guide and watch the full video for the exact readings.
Ranked first
Arco Multi-Grade Graphite Motor Oil (vintage 1970s, API SE/SF/CC)
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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 | Evaporative loss test (400 F, 2 hours) | Lubricity wear scar test | Fuel efficiency test (fuel injected generator) | Cold flow race test at negative 40 F | Independent lab analysis |
|---|---|---|---|---|---|
| 1Arco Multi-Grade Graphite Motor Oil (vintage 1970s, API SE/SF/CC) | started at 411.07 grams, ended at 380.82 grams, a loss of 30.25 grams, more evaporation than Quaker State | produced a dramatically smaller wear scar than Quaker State, a huge difference the presenter did not anticipate | ran 44 minutes and about 10 seconds, roughly 20 seconds shorter than Quaker State, did not improve fuel efficiency | both the new and cooked Arco samples finished behind their Quaker State counterparts, the cooked Arco finished more than 4 inches behind the cooked Quaker State | 6 parts per million iron (contamination present), 0 ppm moly, 1 ppm boron, 1985 ppm calcium, phosphorus almost 3 times Quaker State's level, zinc nearly 3 times Quaker State's level, flashpoint 410 degrees Fahrenheit, higher total base number than Quaker State, normal viscosity |
| 2Quaker State Advanced Durability 10W-40 | started at 430.16 grams, ended at 415.74 grams, a loss of 14.42 grams, described as definitely a Quaker State win | produced a much larger wear scar than the Arco oil | ran 44 minutes and 30 seconds, about 20 seconds longer than the Arco oil | both the new and cooked Quaker State samples finished ahead of their Arco counterparts, the new Quaker State crossed the finish line first overall and the cooked Quaker State beat the cooked Arco by over 4 inches | no trace metals detected, 116 ppm moly, 67 ppm boron, 1447 ppm calcium, 475 ppm phosphorus, under 600 ppm zinc, flashpoint 415 degrees Fahrenheit, lower total base number than the vintage Arco, normal viscosity |
How it was tested
- evaporative loss and thermal breakdown resistance heated to about 400 degrees Fahrenheit for two hours
- lubricity and anti wear film strength wear scar test using the heat cooked oil
- fuel efficiency test using a fuel injected generator run to empty
- cold flow race test at negative 40 degrees Fahrenheit comparing new and heat cooked samples of each brand
- independent oil analysis lab test for trace metals, additive package, viscosity, flashpoint, and total base number
- separate compression test mixing graphite powder into a modern 5W-30 oil and running it in a worn lawnmower engine for about 30 minutes