Which Grease Brand Wins?
A head-to-head test of 2 grease options with the measured results for each. See how they ranked and watch the full test video.
Royal Purple Ultra Performance Grease Multi-Purpose NLGI #2 with Synslide
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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 | Tack/adhesion test (force to separate two grease bonded discs) | Film strength / wear scar test (lubricity tester, 2 minute test) | Corrosion resistance test (rusting agent on wheel stud lug over 24 hr) | Cold temperature low torque test (bearing frozen 24 hr at negative 20 F, force to rotate) | Post cold bearing water submersion test (grease at about 70 F, submerged and rotated at high speed for 30 seconds) | Water spray off test (100 F water jet, quarter inch grease layer, 1 minute) | Dropping point / heat tolerance test | Compatibility test (mixed with Red Line, checked after 24 hr) | Post cold bearing water submersion test | Compatibility test (mixed with Royal Purple, checked after 24 hr) |
|---|---|---|---|---|---|---|---|---|---|---|
| 1Royal Purple Ultra Performance Grease Multi-Purpose NLGI #2 with Synslide | 68.2 lb of strength, narrowly beating Red Line's 67.24 lb, though both brands are described as very close in tack strength | extremely small wear scar; narrator initially thought Royal Purple would win the showdown after seeing its wear scar, but Red Line's scar was ultimately even smaller | no visible rust to the naked eye; under microscope, the corrosion agent got past some of the grease, causing a little corrosion, more oxidation, and patches of oxidation along the threads at the base of the bolt | took a little over 12 lb to rotate, more than Red Line's about 9 lb, about 25 percent more rolling resistance than Red Line | did much better than Red Line, still had adequate grease for the bearings after the test | started at 213.79 g, ended at 213.61 g, losing just a fraction of a gram; spread was about 35.8 mm; described as Royal Purple for the win | advertised drop point over 515 F; began moving at about 520 F and began smoking at the 12 minute mark, while the grease tester read 700 F | no visible change in the condition of the mixed grease | not tested | not tested |
| 2Red Line Synthetic CV2 (NLGI #2 extreme pressure grease, red moly) | 67.24 lb of strength, narrowly behind Royal Purple's 68.2 lb, but described as very close in tack strength | actually beat Royal Purple, producing an even smaller wear scar than Royal Purple's already small scar | no visible rust to the naked eye; under microscope, described as doing a terrific job at corrosion prevention, with only a small amount of oxidation at the base of the bolt where it was submerged in oxidizer and no rust above that area | took a little over 9 lb to rotate, beating Royal Purple's a little over 12 lb, requiring about 25 percent less rolling resistance than Royal Purple when extremely cold | not tested | started at 215.37 g, ended at 215.00 g, losing about 0.37 g; spread was about 50 mm, described as more washed away than Royal Purple | advertised drop point of 800 F; at the grease tester's 700 F reading, Red Line was not even breaking a sweat while Royal Purple was already smoking, described as Red Line for the win | not tested | quite a bit of grease loss inside the bearing set, worse than Royal Purple | no visible change in the condition of the mixed grease |
How it was tested
- tack/adhesion test (force required to separate two metal discs held together by grease)
- film strength / wear scar test (lubricity tester, microscope comparison)
- corrosion resistance test (rusting agent applied to wheel stud lugs vs a bare control bolt over 24 hours)
- cold temperature low torque test (bearings frozen 24 hours at negative 20 F, force to rotate)
- post cold bearing water submersion and grease retention test (rotated in water at high speed)
- water spray off test (heated water jet on a flat grease layer, weighed before and after)
- dropping point / heat tolerance test (heated grease slide)
- grease compatibility test (two brands mixed together, checked after 24 hours)
Data notes and caveats
No single declared overall winner: narrator's closing summary is a per-category split, Royal Purple better for water exposure, Red Line better in every other category tested (film strength/wear scar, corrosion, cold temperature torque, dropping point/heat), with tack/adhesion very close. The title and description frame the question as synthetic grease versus Lucas Red-N-Tacky, but Lucas is only referenced from a previous video for context in the intro and is not actually tested in this video; only Royal Purple and Red Line are tested here, matching the description's Products Tested list.
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