Top 5 DEXRON ULV Transmission Fluids for GM 10-Speed Transmissions
- Greg Nelson
- 6 days ago
- 11 min read
Updated: 16 minutes ago
GM’s modern 10-speed automatic transmissions brought with them a very different transmission fluid requirement: DEXRON ULV.
ULV stands for Ultra-Low Viscosity, and the name is accurate. Most of the fluids specifically formulated for DEXRON ULV applications are only around 4.5 cSt at 100°C — substantially thinner than older automatic transmission fluids.
That low viscosity is intentional.
Modern transmissions such as the GM 10L80 and 10L90 rely on their transmission fluid for much more than simply lubricating gears and bearings. The fluid is also a critical part of the hydraulic and friction system controlling clutch engagement, shift timing and torque-converter-clutch operation.
So choosing an ATF isn't simply a matter of finding the thickest fluid or the one with the most aggressive marketing claims.
For this comparison, we looked at five popular DEXRON ULV options using the manufacturers' published technical information, including:
Kinematic viscosity at 40°C
Kinematic viscosity at 100°C
Viscosity Index
Cold-temperature performance where available
Friction durability claims and testing
OEM approval or application recommendations
Overall technical package
And after correcting and verifying the numbers, one thing became very clear:
Most legitimate ULV fluids are remarkably similar in viscosity.
The bigger differences may be found in their friction characteristics, cold-temperature performance, additive packages and ability to maintain those properties as the fluid ages.
That's where this comparison gets interesting.
Affiliate Disclosure
Some links in this article may be affiliate links. If you purchase through these links, DuramaxNews may earn a small commission at no additional cost to you. These commissions help support the website, future testing and technical content.
Affiliate relationships do not determine the rankings in this article. Rankings are based on published technical data, OEM compatibility and our technical evaluation of each product.
What Makes DEXRON ULV Different?
DEXRON ULV should not be confused with DEXRON VI.
The viscosity numbers alone show just how thin modern ULV fluid really is.
Looking across the dedicated ULV fluids in this comparison, most fall around:
19–20.5 cSt @40°C
and
4.45–4.62 cSt @100°C
That's an extremely tight viscosity range.
A modern 10-speed transmission depends on carefully controlled hydraulic circuits. Fluid viscosity can influence:
clutch fill behavior
hydraulic response
shift characteristics
torque-converter-clutch operation
cold-temperature performance
internal pumping losses
But viscosity isn't everything.
Automatic transmission fluid must also maintain very specific friction characteristics.
The transmission's clutch packs need enough friction to hold torque while also engaging progressively enough to produce a smooth shift. Those characteristics need to remain consistent as the fluid accumulates miles, heat cycles and clutch material contamination.
That means a fluid can have perfect viscosity numbers and still differ substantially from another fluid in friction durability, oxidation resistance, anti-shudder performance and long-term shift quality.
With that in mind, here's our ranking.
#1 — TRIAX ULV ATF
BUY TRIAX ULV ATF: https://amzn.to/4wNO2fW
TRIAX takes our #1 position — but not because it's dramatically thicker than factory ULV fluid.
It's actually remarkably close.
TRIAX ULV Technical Data
Property | TRIAX ULV ATF |
Kinematic Viscosity @40°C | 19.88 cSt |
Kinematic Viscosity @100°C | 4.62 cSt |
Viscosity Index | 157 |
Brookfield Viscosity @-40°C | 6,194 cP |
Pour Point | -60°C (-76°F) |
Specific Gravity @60°F | 0.831 |
DEXRON ULV Licensed | No |
Those viscosity numbers put TRIAX directly within the normal ULV range.
At operating temperature, TRIAX's 4.62 cSt is only slightly above the approximately 4.5 cSt values published for several other ULV fluids in this comparison.
Its 157 Viscosity Index is also one of the higher published VI numbers in this group.
But neither of those specifications is the primary reason TRIAX takes our #1 position.
The Big Difference: Friction Durability
TRIAX publishes results from an S1/D frictional durability test comparing its friction performance against an OEM comparison fluid.
According to TRIAX, its fluid showed approximately:
5% shift degradation
compared with:
55% degradation for the OEM comparison fluid.
TRIAX markets the result as providing up to 72% smoother shifts for much longer.
TRIAX's published S1/D frictional durability comparison. Results are manufacturer-provided. DuramaxNews has not independently reproduced this testing.
This is particularly interesting in a modern 10-speed transmission.
As ATF ages, maintaining stable friction characteristics helps the transmission continue to produce predictable clutch engagement and shift behavior.
TRIAX markets its SURE SHIFT friction technology specifically around maintaining frictional performance, resisting shudder and maintaining shift quality.
And unlike our original assumption, TRIAX isn't accomplishing this by simply making the fluid substantially thicker.
Its 19.88 cSt @40°C and 4.62 cSt @100°C viscosity numbers remain extremely close to the established ULV range.
An Important Testing Disclaimer
We do need to put TRIAX's friction testing into perspective.
The S1/D comparison is TRIAX's published manufacturer testing.
We have not independently reproduced the test, and the marketing graphic does not identify the exact OEM fluid used in the comparison.
Therefore, we don't consider the graph proof that TRIAX will outperform every DEXRON ULV fluid in every transmission.
We do, however, consider friction durability extremely relevant when evaluating an automatic transmission fluid, and TRIAX provides compelling published data in this area.
There's another factor we consider when evaluating the brand.
TRIAX has obtained official GM dexos approval on some of its engine oils.
That does not mean TRIAX ULV ATF is GM approved or DEXRON ULV licensed. Those are completely separate products and approval programs.
But it does demonstrate that TRIAX has participated in GM's formal lubricant approval process with other products.
Pros
Excellent ULV viscosity profile
4.62 cSt @100°C
Strong 157 Viscosity Index
-60°C pour point
Published S1/D friction durability testing
SURE SHIFT friction technology
Specifically formulated for ULV applications
Manufacturer has experience obtaining GM approvals on other lubricant products
Cons
Not officially DEXRON ULV licensed
S1/D comparison is manufacturer-provided testing
Exact OEM comparison fluid isn't identified in the marketing graphic
6,194 cP Brookfield @-40°C is higher than several competitors in this comparison
Technical Verdict
TRIAX earns #1 because its viscosity remains extremely close to the established ULV range while the company also provides an interesting argument around friction durability.
In a modern automatic transmission, maintaining the proper friction characteristics over time may ultimately matter more than a few tenths of a centistoke of viscosity.
For someone willing to move away from the factory fluid, TRIAX ULV is currently our #1 aftermarket choice.
#2 — ACDelco DEXRON ULV
BUY ACDelco DEXRON ULV: https://amzn.to/4pRunsW
If your goal is simple — use exactly what GM specifies — ACDelco DEXRON ULV is the obvious choice.
This is the factory fluid specification around which GM's DEXRON ULV applications were developed.
ACDelco DEXRON ULV Technical Data
The DEXRON ULV safety data sheet lists:
Property | DEXRON ULV |
Kinematic Viscosity @40°C | 19–20 cSt |
Kinematic Viscosity @100°C | 4.4–4.6 cSt |
Relative Density @15.6°C/60°F | 0.83–0.85 |
OEM Specification | GM DEXRON ULV |
Because the SDS provides viscosity as a range rather than one typical value, we aren't going to invent additional precision.
For easy comparison, the midpoint of those ranges would be approximately 19.5 cSt @40°C and 4.5 cSt @100°C, but those midpoint values are calculations — not separate GM-published specifications.
These numbers make considerably more sense when compared with the rest of the ULV market.
A Note About Conflicting GM Data
There is an important discrepancy worth mentioning.
A GM online parts listing has published a 29.2 cSt @40°C figure for ACDelco DEXRON ULV.
However, the DEXRON ULV SDS lists 19–20 cSt @40°C and 4.4–4.6 cSt @100°C.
The SDS figures also align very closely with Ford MERCON ULV and virtually every dedicated aftermarket ULV fluid in this comparison.
For that reason, we're using the viscosity range published in the DEXRON ULV SDS for this comparison.
Why Isn't Factory DEXRON ULV #1?
There's nothing wrong with putting it #1.
In fact, if our ranking were based entirely on OEM specification confidence, it would win.
GM selected the friction and viscosity requirements for these transmissions. There is inherent value in using the fluid designed around those requirements rather than assuming an aftermarket formulation is better.
TRIAX only edges it out in our overall ranking because we're specifically evaluating aftermarket technical differences and TRIAX provides additional published friction-durability data that we find interesting.
Pros
Factory GM specification
No question about intended application
Correct ULV viscosity range
Maximum OEM specification confidence
Best choice for owners who don't want to experiment with aftermarket fluids
Cons
Less published performance data for consumers
Doesn't provide the same friction-durability comparison TRIAX publishes
Aftermarket products may offer additional published performance testing
Technical Verdict
For the owner asking:
"What is the safest fluid choice for my stock GM 10-speed?"
Our answer remains:
ACDelco DEXRON ULV.
There's no need to overthink it.
#3 — Valvoline ULV Full Synthetic ATF
BUY VALVOLINE ULV: https://amzn.to/4buwIEh
Valvoline's ULV Full Synthetic ATF may be the least controversial aftermarket alternative in this comparison.
Its numbers are almost exactly what we would expect from a dedicated ULV formulation.
Valvoline ULV Technical Data
Property | Valvoline ULV |
Kinematic Viscosity @40°C | 19.41 cSt |
Kinematic Viscosity @100°C | 4.45 cSt |
Viscosity Index | 146 |
Brookfield Viscosity @-40°C | 4,780 cP |
Pour Point | -57°C |
Specific Gravity @60°F | 0.848 |
Valvoline specifically recommends the fluid for applications requiring DEXRON ULV or MERCON ULV, including the GM 10L80 and 10L90.
The most important numbers are:
19.41 cSt @40°C
and
4.45 cSt @100°C.
That's almost exactly in the middle of the established ULV viscosity range.
Valvoline also publishes a 4,780 cP Brookfield viscosity at -40°C, giving us a useful indication of its cold-temperature fluidity.
Pros
Extremely close to DEXRON ULV viscosity
4.45 cSt @100°C
Good 4,780 cP Brookfield result @-40°C
-57°C pour point
Major established lubricant manufacturer
Specifically recommended for GM 10L80 and 10L90 applications
Widely available
Cons
Not the factory GM-branded fluid
VI of 146 is lower than TRIAX's published 157
Limited reason to choose it over OEM based solely on viscosity
Technical Verdict
If you want a widely available aftermarket fluid that stays extremely close to the expected ULV viscosity profile, Valvoline is one of the easiest products on this list to recommend.
#4 — AMSOIL Signature Series ULV ATF
BUY AMSOIL SIGNATURE SERIES ULV: amsoil.com
There's an important distinction with AMSOIL.
AMSOIL sells multiple automatic transmission fluids, and some of its other ATFs are substantially thicker.
For this comparison, we're specifically evaluating:
AMSOIL Signature Series Ultra-Low Viscosity Synthetic Automatic Transmission Fluid.
That's the product AMSOIL lists for applications requiring GM DEXRON ULV and Ford MERCON ULV.
AMSOIL ULV Technical Data
Property | AMSOIL ULV |
Kinematic Viscosity @40°C | 20.5 cSt |
Kinematic Viscosity @100°C | 4.5 cSt |
Viscosity Index | 134 |
Brookfield Viscosity @-40°C | 4,050 cP |
Pour Point | -62°C (-80°F) |
Flash Point | 220°C (428°F) |
Four-Ball Wear Scar | 0.39 mm |
The viscosity numbers are again very close to the factory ULV range.
But AMSOIL becomes particularly interesting when we look at cold-temperature performance.
Its published 4,050 cP Brookfield viscosity at -40°C is lower than:
TRIAX — 6,194 cP
Valvoline — 4,780 cP
Ford MERCON ULV — 4,500 cP
Lower Brookfield viscosity at the same temperature indicates less resistance to flow under that specific cold-temperature test.
AMSOIL also publishes an extremely low -62°C (-80°F) pour point.
What About Its Lower Viscosity Index?
AMSOIL's VI of 134 is noticeably lower than TRIAX's 157 or Ford's 152.
But VI should not be used as a simple quality score.
The actual measured viscosity and cold-temperature test results matter.
And AMSOIL's measured cold-temperature numbers are very strong.
Pros
Excellent 4.5 cSt operating-temperature viscosity
4,050 cP Brookfield @-40°C
Excellent -62°C pour point
Specifically listed for DEXRON ULV applications
Published Four-Ball Wear Test result
Strong severe-service reputation
Cons
Not the factory GM fluid
VI is lower than the other fluids in this comparison
Premium pricing
Some buyers may accidentally purchase AMSOIL's different ATF formulations instead of the dedicated ULV product
Technical Verdict
For someone operating in extremely cold conditions, AMSOIL may actually have the most interesting published specifications in this comparison.
Its combination of 4.5 cSt operating viscosity and strong -40°C Brookfield performance makes it a technically compelling ULV fluid.
#5 — Hot Shot's Secret Green Diamond ULV ATF
BUY HOT SHOT'S SECRET GREEN DIAMOND ULV: Hot Shots - https://amzn.to/4g9NsDu
Doc's - https://amzn.to/4zddA8f
Hot Shot's Secret also offers a dedicated ULV formulation, and its current technical data puts it much closer to OEM-style ULV than we initially expected.
Green Diamond ULV Technical Data
Property | Green Diamond ULV |
Kinematic Viscosity @40°C | 19.74 cSt |
Kinematic Viscosity @100°C | 4.513 cSt |
Viscosity Index | 147.3 |
Flash Point | 210°C (410°F) |
Pour Point | -50°C (-58°F) |
Copper Corrosion | 1b |
Hot Shot's lists the fluid for applications requiring GM DEXRON ULV and Ford MERCON ULV WSS-M2C949-A.
From a viscosity standpoint, Hot Shot's is remarkably close to Valvoline.
At 100°C:
Valvoline: 4.45 cSt
Hot Shot's: 4.513 cSt
That's a tiny difference.
Hot Shot's differentiates the product primarily through its additive technology and performance claims, including its proprietary FR3 Nano Technology.
Those manufacturer claims are interesting, but they aren't directly comparable with the standardized viscosity numbers we're using throughout this article.
Pros
Excellent match to typical ULV viscosity
4.513 cSt @100°C
147.3 Viscosity Index
Dedicated DEXRON ULV formulation
Full synthetic Group III formulation
Strong additive and wear-protection claims
Cons
Not the factory GM fluid
-50°C pour point is higher than several competitors
No published -40°C Brookfield number on the technical sheet we're using
Some performance advantages rely on proprietary manufacturer claims rather than directly comparable testing
Technical Verdict
Hot Shot's ranking #5 should not be interpreted as us calling it a poor fluid.
Its actual viscosity numbers are extremely close to the other dedicated ULV fluids.
DEXRON ULV Fluid Comparison
Here's what the numbers actually look like side-by-side:
Fluid | KV40 | KV100 | VI | Brookfield @-40°C | Pour Point |
TRIAX ULV | 19.88 | 4.62 | 157 | 6,194 cP | -60°C |
ACDelco DEXRON ULV | 19–20 | 4.4–4.6 | — | — | — |
Valvoline ULV | 19.41 | 4.45 | 146 | 4,780 cP | -57°C |
AMSOIL ULV | 20.5 | 4.5 | 134 | 4,050 cP | -62°C |
Hot Shot's Green Diamond ULV | 19.74 | 4.513 | 147.3 | Not Published | -50°C |
KV40 and KV100 are kinematic viscosity in cSt.
This table changes the entire conversation.
Look specifically at the 100°C numbers:
4.624.4–4.64.454.504.513
These fluids are extremely close.
The spread between Valvoline at 4.45 cSt and TRIAX at 4.62 cSt is only 0.17 cSt.
That's why we don't think choosing an ULV fluid based solely on which one is "thicker" makes much sense.
The more important differences may involve:
friction durability
anti-shudder characteristics
oxidation stability
shear stability
additive chemistry
cold-temperature performance
clutch-material compatibility
long-term performance
Unfortunately, manufacturers don't all publish the same tests, making direct comparisons difficult.
Final Rankings
There really isn't a "bad" fluid in this group based on the technical data we've reviewed.
The bigger question is what you're trying to accomplish.
Want the factory answer?
Use ACDelco DEXRON ULV.
Want a mainstream aftermarket alternative?
Valvoline makes a strong argument.
Live somewhere extremely cold?
AMSOIL's published cold-temperature numbers deserve attention.
Want the aftermarket fluid we find most technically interesting overall?
That's TRIAX.
BONUS — How Does Ford MERCON ULV Compare?
Ford's factory MERCON ULV fluid provides an extremely useful reference point.
GM and Ford's modern 10-speed transmissions share development history, and the fluid numbers show just how similar their ULV strategies are.
Motorcraft MERCON ULV Technical Data
Property | Motorcraft MERCON ULV |
Kinematic Viscosity @40°C | 19.2 cSt |
Kinematic Viscosity @100°C | 4.5 cSt |
Viscosity Index | 152 |
Brookfield Viscosity @-40°C | 4,500 cP |
Pour Point | < -51°C (< -60°F) |
Flash Point | 190°C (370°F) |
Specific Gravity @60°F | 0.841 |
License Number | MERCON ULV MULV160703 |
Ford's official data sheet confirms those specifications.
Now compare its viscosity directly with the five fluids above:
Fluid | KV40 | KV100 |
Motorcraft MERCON ULV | 19.2 | 4.5 |
ACDelco DEXRON ULV | 19–20 | 4.4–4.6 |
Valvoline ULV | 19.41 | 4.45 |
Hot Shot's ULV | 19.74 | 4.513 |
TRIAX ULV | 19.88 | 4.62 |
AMSOIL ULV | 20.5 | 4.5 |
That's remarkably consistent.
Ford's factory MERCON ULV essentially confirms what the rest of this comparison is telling us:
A true modern ULV ATF lives right around 4.5 cSt at operating temperature.
So Which DEXRON ULV Fluid Would We Actually Use?
If the vehicle is under warranty and the owner wants absolutely no discussion about fluid selection:
ACDelco DEXRON ULV.
That's the factory answer.
But if we're specifically comparing aftermarket alternatives, TRIAX ULV gets our #1 ranking.
And after digging deeper into the data, our reason for choosing it has actually changed.
It isn't because TRIAX is substantially thicker.
It isn't.
Its viscosity is remarkably close to the rest of the ULV market.
What separates it for us is the combination of:
19.88 cSt @40°C
4.62 cSt @100°C
157 Viscosity Index
-60°C pour point
dedicated ULV formulation
published friction-durability testing
Most importantly, TRIAX's S1/D testing attempts to answer a question that viscosity specifications can't:
How well does the fluid maintain the friction characteristics responsible for shift quality as it ages?
TRIAX claims approximately 5% degradation versus 55% for the OEM comparison fluid in that test.
That's a significant result — and one of the main reasons it earns our #1 position.
But we're also going to keep that claim in perspective.
It's manufacturer-provided testing, the exact OEM comparison fluid isn't identified in the marketing graphic, and we haven't independently reproduced the test.
So we're not claiming TRIAX has proven it will make every 10L80 last longer.
We're saying its combination of OEM-like ULV viscosity and compelling published friction-durability data makes it the aftermarket fluid we currently find most interesting.
And that's a distinction we're comfortable making.
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