2017 test2 productsEngine Oil & Fluids
Which Fuel And Oil Additive Brand Wins?
A head-to-head test of 2 fuel and oil additive 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
Marvel Mystery Oil
Price shown in test: $3.50 for 32 oz
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 | Application method | Cold compression test | Prior video results referenced |
|---|---|---|---|
| 1Marvel Mystery Oil$3.50 for 32 oz | added via a bag-and-clamp setup to control flow rate into the carburetor, 8 oz added to match the amount used with SeaFoam in a prior video, followed by a hot soak of the engine with additional Marvel Mystery Oil for at least 20 minutes with the spark plug removed | a video chapter title reads '106 PSI cold,' but the transcript's spoken narration does not state this figure or confirm which product it belongs to; kept as an unconfirmed, chapter-only data point | not tested |
| 2SeaFoam$7 to $10 a can for 16 oz | not tested | not tested | described as having done a phenomenal job improving engine compression and removing carbon deposits from the combustion chamber |
How it was tested
- cold engine compression test
- warm engine compression test
- hot soak treatment of the engine with the additive
- carbon deposit removal (referenced from a prior SeaFoam video, not retested here)