2019 test2 productsEngine Oil & Fluids

Which Motor Oil Brand Wins?

We compared 2 motor oil options head to head. Quaker State 10W-40 (modern) came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.

The verdict
Winner

Quaker State 10W-40 (modern)

Check price on Amazon

Affiliate link. We may earn a commission at no extra cost to you.

Runner-up

Quaker State vintage (1950s/60s)

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.

ProductAPI ratingEvaporative loss (410F for 2 hours)Lubricity/film strength testCold oil flow test (after 24 hours at minus 40F)Oil analysis, molyOil analysis, phosphorusOil analysis, zincOil analysis, TBNPackagingSmall engine run (16 oz added to a small engine)Oil analysis, calcium
1Quaker State 10W-40 conventional motor oil (modern)has the API donut, API service SN, meets or exceeds API SN and previous API categoriesstarted at 430 g, ended at 423.37 g, a loss of 6.63 gwon the showdown against the vintage oilnew Quaker State was first across the finish line, 2 inches ahead of the cooked Quaker State sample116 parts per million475 parts per million581 parts per million6.2, described as pretty averagenot testednot testednot tested
2Quaker State vintage oil, approximately 60 to 70 years old (1950s can)not testedstarted at 404.56 g, ended at 395.13 g, a loss of 9.43 g, described as a lot of evaporative losslost to the modern oil but did not do too badlyvery sluggish and the last to move meaningfully; described as not liking the cold temperature at all0 parts per million (none detected)475 parts per million509 parts per million0.4, described as extremely lowno viscosity grade rating and no API donut on the canslight drop in compression; teardown showed crusty buildup on the cylinder head and around the intake and exhaust valves, plus vapor from the positive crankcase ventilationonly 6 parts per million

How it was tested

  • NOACK-style evaporative loss test at 410F for 2 hours
  • lubricity/film strength wear-scar test
  • small engine run with compression check and cylinder head teardown
  • cold oil flow race after 24 hours at minus 40F, cooked and uncooked samples of both oils
  • independent oil lab analysis (moly, phosphorus, zinc, calcium, boron, TBN)

Actually, modern motor oil did win the showdown as far as the lubricity test, but the vintage didn't do too bad.

From the test video verdict.

More Engine Oil & Fluids