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Oil & Engine Additives

Do Stop Leak Products Work? Do They Damage Engine Seals? Will They Destroy an Engine? Let's Find Out

Feb 2023/19 min/14 products tested

Watch the test ↗

The verdict

  1. 1

    AT-205

    avg finish 3.6

    “the AT-205 easily won this showdown with an average finish of first place”
    Buy on Amazon ↗
  2. 2

    Seal Lube

    avg finish 4.4

    “the AT-205 had an average finish of 3.6 and Seal Lube 4.4.”
    Buy on Amazon ↗

Other picks

  • Also noted

    AT-205

    “there are potential risks with using stop leak products and I would never use a stop leak product in a vehicle that didn't have an active leak”
    Buy ↗

Everything tested 14

Links go to Todd's own Amazon listings with his affiliate tag intact — this site adds nothing and takes nothing.