Motor Oil Aug 2021 Test: Which Brand Wins?
In our Aug 2021 test we compared 2 motor oil options head to head. Pennzoil Platinum Full Synthetic came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.
Pennzoil Platinum Full Synthetic
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Honda Marine
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The quick take
The short version of why each pick lands where it does, built straight from the measured results.
“In my opinion, stick with the oil that's designed for a car. Unfortunately, the marine oil just did not perform very well compared to the oil that's designed for a car.”
The measured results
Every number below is read straight from the test. Products are listed in the order they finished.
All measurements (14 more)+
Evaporative loss (410F for 2 hours)
- 1Pennzoil Platinum Full Synthetic 10W-30
started at 410.9 g, ended at 407 g, a loss of only 3.9 g, described as a huge win over Honda Marine
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)
started at 404.64 g, ended at 385.86 g, a loss of 18.78 g, far worse than Pennzoil
Foam/anti-foaming test (5 minutes)
- 1Pennzoil Platinum Full Synthetic 10W-30
cleared up much faster and more completely than the Honda Marine oil
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)
had noticeably more air bubbles remaining and cleared more slowly than Pennzoil, despite manufacturer claims of a superior anti-foaming package
Corrosion test, 2-minute check
- 1Pennzoil Platinum Full Synthetic 10W-30
appeared to have slightly more oxidation than Honda Marine at this early check
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)
appeared to have less oxidation than Pennzoil at this early check
Corrosion test, 24-hour final result (rusting agent applied 3 times)
- 1Pennzoil Platinum Full Synthetic 10W-30
both oils did very well, but Pennzoil showed a bit more rust, especially in size and intensity, compared to Honda Marine
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)
both oils did very well, but Honda Marine showed less rust in size and intensity than Pennzoil
Lubricity/film strength test
- 1Pennzoil Platinum Full Synthetic 10W-30
lost narrowly to Honda Marine, which had about a 3 percent smaller wear scar; described as the closest race between two brands the presenter had seen in a long time
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)
won narrowly with about a 3 percent smaller wear scar than Pennzoil
Cold oil flow race (new and cooked samples, minus 40F)
- 1Pennzoil Platinum Full Synthetic 10W-30
won the overall race; the cooked Pennzoil sample staged a comeback to cross the finish line slightly ahead of Honda Marine
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)
competitive throughout but ultimately lost; the cooked Pennzoil sample edged it out at the finish
Oil analysis, moly
- 1Pennzoil Platinum Full Synthetic 10W-3071 parts per million
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)37 parts per million
Oil analysis, boron
- 1Pennzoil Platinum Full Synthetic 10W-30209 parts per million
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)2 parts per million
Oil analysis, calcium
- 1Pennzoil Platinum Full Synthetic 10W-30863 parts per million
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)1,819 parts per million
more than double Pennzoil's
Oil analysis, magnesium
- 1Pennzoil Platinum Full Synthetic 10W-30613 parts per million
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)11 parts per million
Oil analysis, phosphorus
- 1Pennzoil Platinum Full Synthetic 10W-30557 parts per million
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)1,039 parts per million
nearly double Pennzoil's
Oil analysis, zinc
- 1Pennzoil Platinum Full Synthetic 10W-30619 parts per million
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)1,203 parts per million
nearly double Pennzoil's
Oil analysis, flash point
- 1Pennzoil Platinum Full Synthetic 10W-30460F
better than Honda Marine's 400F
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)400F
lower than Pennzoil's 460F
Oil analysis, TBN
- 1Pennzoil Platinum Full Synthetic 10W-306.5
slightly higher than Honda Marine's 5.9
- 2Honda Marine SAE 10W-30 (Honda Genuine Oil, meets NMMA FC-W)5.9
slightly lower than Pennzoil's 6.5
How it was tested
- NOACK-style evaporative loss test at 410F for 2 hours
- anti-foaming test using a shaken quart jar setup
- corrosion resistance test using a hydrogen peroxide, vinegar, and salt mix, checked at 2 minutes and again at 24 hours
- lubricity/film strength wear-scar test
- cold oil flow race at minus 40F, new and heat-cooked samples of both oils
- independent oil lab analysis (moly, boron, calcium, magnesium, phosphorus, zinc, flash point, TBN)
“In my opinion, stick with the oil that's designed for a car. Unfortunately, the marine oil just did not perform very well compared to the oil that's designed for a car.”
