Myth test1 productsEngine Oil & Fluids

Oil Additive: The Test Results

A head-to-head test of 1 oil additive options with the measured results for each. See how they ranked and watch the full test video.

The verdict
Ranked first

Liqui Moly Cera Tec

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.

ProductFilm Strength TestFrictional Loss TestFuel Efficiency TestCompression TestCombustion Chamber Deposits Test
1Liqui Moly Cera Tecslightly better film strength than regular 10W-30 oil in the lubricity tester comparison (10W-30 alone vs. Cera Tec alone vs. a 6% Cera Tec/10W-30 mix per the manufacturer's instructions), but the narrator notes other additive products tested previously showed a lot better film strengthin the small engine test (governor disconnected, throttle wired open so RPM reflects internal friction), adding Cera Tec to the crankcase after a 10W-30-only baseline run of a little over 67 minutes produced an RPM increase, interpreted as reduced internal friction; no specific before/after RPM figures are stated in the transcriptimproved fuel efficiency by almost 1% when tested in the generatordid not improve compression after five tanks of fuel; compression was described as lower than the engine had shown in the pasta lot of buildup observed on the piston and cylinder head, though the narrator cautions this may not be entirely attributable to the product since five tanks of fuel were run through the engine instead of the usual one tank

How it was tested

  • lubricity/film strength test comparing 10W-30 oil, Cera Tec alone, and a 6% Cera Tec/10W-30 mix
  • small engine frictional loss test (RPM change after adding the product to the crankcase)
  • fuel efficiency test using a generator
  • compression test after five tanks of fuel
  • combustion chamber and spark plug deposit inspection

Personally, I don't think it's snake oil. I just don't think it's the best product we've tested today. However, I do think it's a product that delivers on some of the results it claims.

From the test video verdict.

More Engine Oil & Fluids