Which Automatic Transmission Fluid (Dexron VI) Brand Wins?
We compared 4 automatic transmission fluid (dexron vi) options head to head. Red Line D6 ATF came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.
Red Line D6 ATF
Price shown in test: $23 per quart, almost three times the price of the ACDelco
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SuperTech
Price shown in test: around $9 per quart, about a dollar more than the ACDelco
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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 | Certifications/specs | Thermal breakdown/evaporation (200g heated to 410F for 2 hours) | Lubricity/wear scar test | Flow speed race, new fluid at ~70F (all four) | Flow speed race, cooked fluid at ~70F (all four) | Foaming resistance (5 minutes) | Cold flow race at -40F, new fluid | Cold flow race at -40F, cooked fluid | Independent oil analysis lab report | Lubricity/wear scar test vs ACDelco | Lubricity/wear scar test vs SuperTech |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1Red Line D6 ATF (high performance)$23 per quart, almost three times the price of the ACDelco | recommended for GM Dexron VI applications and several others, made in USA | started 404.79 g, ended 397.85 g, a loss of just under 7 g, the best (least) evaporation of the four | the smallest wear scar of the four, though by less than 1 percent smaller than the ACDelco/Mobil tie; declared the best for wear resistance, finished 1st | tied for 3rd place with ACDelco, all four within 1.17 to 1.22 seconds of each other | 2nd place; only a 1.6 percent performance loss versus new fluid, the smallest loss of the four | passed, no foaming; described as performing best overall heading into this test and retaining its dark red color longer than the others under heat | 1st place by far, 24.53 seconds, described as destroying the competition, winning by over 3 inches | 1st place by far, 27.37 seconds, winning by about 5 inches; only a 10.4 percent performance loss versus its own new-fluid time, the smallest loss of the four | by far the most robust detergent/dispersant additive package at over 300 parts per million; by far the most robust anti-wear additive package at 2.5 times more anti-wear additives than the competition; total acid number under 2 like the others; only trace levels of wear metals (iron, tin) | not tested | not tested |
| 2SuperTecharound $9 per quart, about a dollar more than the ACDelco | full synthetic, Dexron VI, claims compatibility with both Dexron and Mercon applications, manufactured in USA | started 394.64 g, ended 386.3 g, a loss of 8.34 g, edging out the ACDelco by just over a gram for 2nd place | not tested | 1st place, winning by less than an inch | 1st place again; a 7.1 percent performance loss versus new fluid | passed, no foaming for the full 5 minutes | barely edged out ACDelco for 3rd place, around 34.5 seconds | 3rd place at 40.14 seconds, about an inch ahead of ACDelco; a 14.2 percent performance loss versus new fluid | detergent/dispersant and anti-wear additive levels described as close to the same as ACDelco and Mobil (well below Red Line's); total acid number under 2 like the others | wear scar of 8.44 mm, about 5 percent more damage/larger than the ACDelco's; lost this pairing to ACDelco and finished 4th (last) overall on wear resistance | not tested |
| 3Mobil$13 per quart, $4 more than SuperTech | synthetic blend (the only one of the four not full synthetic), for General Motors vehicles, claims improved oxidation/thermal stability, optimized friction performance, improved anti-wear protection; made in USA | started 410.87 g, ended 390.26 g, a loss of 20.61 g, more than twice the loss of ACDelco or SuperTech and by far the worst of the four; became visibly dark and produced a lot of vapor early in the test | not tested | 2nd place, close behind SuperTech | 3rd place; a 5.4 percent performance loss versus new fluid | passed, no foaming | 2nd place at 30.16 seconds, well ahead of ACDelco and SuperTech by over 2 inches, a strong result for a synthetic blend | 2nd place at 39.88 seconds, though heat exposure sharply cut into its lead over ACDelco/SuperTech; a 24.4 percent performance loss versus new fluid, the largest loss of the four | detergent/dispersant and anti-wear additive levels described as close to the same as ACDelco and SuperTech (well below Red Line's); total acid number under 2 like the others | tied precisely with ACDelco for the same size wear scar, described by the narrator as the first time this exact tie has happened in his lubricant testing; tied for 2nd place overall on wear resistance | not tested |
| 4ACDelcoaround $8 per quart | Dexron VI, full synthetic, distributed by General Motors LLC, recommended for GM transmissions 2006 and newer but claimed backward compatible with older Dexron transmissions | started 429.88 g, ended 420.25 g, a loss of 9.63 g, the worst of the three non-Mobil fluids (3rd place among the four) | not tested | tied for 3rd place with Red Line, all four within 1.17 to 1.22 seconds of each other | 4th (last) place; a 7.7 percent performance loss versus new fluid, the largest loss of the four in this specific race | passed, no foaming | 4th (last) place, around 34.5 seconds, very close to SuperTech | 4th (last) place at 42.78 seconds; a 19 percent performance loss versus new fluid | detergent/dispersant and anti-wear additive levels described as close to the same as SuperTech and Mobil (well below Red Line's); total acid number under 2 like the others | not tested | wear scar of about 8 mm, smaller than SuperTech's 8.44 mm, winning this pairing; tied with Mobil for 2nd place overall on wear resistance |
How it was tested
- thermal breakdown/evaporation (Noack-style): 200g of fluid heated to 410F for 2 hours, weighed before and after (run as two pairs: ACDelco vs SuperTech, then Mobil vs Red Line)
- lubricity/wear scar test using heat-exposed (cooked) fluid on a lubricity tester (same two pairs)
- flow speed race at approximately 70F, all four fluids simultaneously, both new and heat-exposed (cooked) fluid
- foaming resistance: fluid shaken and observed for bubble formation over 5 minutes
- cold flow race at -40F in a freezer (about 10 hours), all four fluids simultaneously, both new and heat-exposed (cooked) fluid
- independent oil analysis lab report: wear metals, detergent/dispersant content, anti-wear additive levels, and total acid number (TAN)
“The Red Line completely dominated the competition with the first place finish in every category.”
Data notes and caveats
Only 2 of the video's many sub-tests have dedicated meta chapters (Protection against Foaming, Most Robust Additive Package); everything else falls inside one large untitled chapter, so chapterMap is false despite the transcript itself being very clean and internally consistent. The evaporation and lubricity/wear-scar tests were each run as two separate pairs (ACDelco vs SuperTech, then Mobil vs Red Line) rather than as one simultaneous four-way test, though the video does synthesize a combined four-way ranking afterward for both. SuperTech's runner-up finish (average rank 2.8) comes despite it finishing dead last specifically on wear resistance, which the narrator explicitly flags as his biggest concern with that brand; this is not a contradiction, just an average across categories where SuperTech excelled at both flow-speed races. No explicit budget/value pick is framed by the narrator in this video (unlike some other Project Farm videos), so budgetPick is left null even though ACDelco is the cheapest brand tested at about $8 per quart; it did not perform particularly well overall (last or near-last in cooked flow speed and both cold-flow races).