Short answer
Dexron ULV is a General Motors automatic transmission fluid specification for an ultra-low viscosity fluid, used in GM’s 10-speed automatic transmissions. It is thinner than Dexron VI and is not a substitute for it, and Dexron VI is not a substitute for ULV. GM also maintains a separate Dexron HP specification for other late-model transmissions.
Why GM created a ULV fluid
Modern automatics with eight, nine or ten forward ratios are designed around thinner fluids. Lower viscosity reduces the energy lost to pumping and churning fluid, which helps fuel economy, but it only works if the transmission’s pump, clutches and bearings were engineered for it.
Dexron ULV is GM’s answer for its 10-speed automatics. Ford developed its own ultra-low viscosity fluid, Mercon ULV, for the 10-speed family it shares with GM, which is why several aftermarket fluids list both names.
Dexron ULV, Dexron HP and Dexron VI
GM now has three current automatic transmission fluid families in common use. Dexron VI covers a large share of GM automatics from 2006 onward. Dexron HP is a fully synthetic GM specification used in certain later transmissions. Dexron ULV covers the 10-speed units.
These are not simply better and worse versions of one fluid. They differ in viscosity and in the friction behavior each transmission’s clutches were calibrated to. Up until the low-viscosity fluids arrived, many ATFs were broadly backward compatible; that assumption no longer holds for HP and ULV applications.
Checking which fluid your GM vehicle needs
The owner’s manual fluid table is the first place to look. Many GM transmissions also have the fluid name on a tag or cast into the case near the fill or check plug, and a dealer parts department can confirm by VIN.
If a vehicle has had a transmission replaced or a service history you can’t confirm, it’s worth verifying the transmission model before ordering fluid rather than assuming by model year.
What “meets” and “recommended for” mean on a ULV label
GM licenses its Dexron names, and a licensed fluid displays the Dexron mark. Many multi-vehicle and aftermarket ULV fluids instead say they are recommended for Dexron ULV applications. That is the supplier’s statement, not a GM license.
Whichever kind you choose, compare the exact specification name against the manual and read the current product data sheet before filling.
Frequently asked questions
Can I put Dexron VI in a GM 10-speed?
Not if the manual calls for Dexron ULV. Dexron VI is a thicker fluid built to a different specification. Use the fluid the manual names.
Is Dexron ULV the same as Ford Mercon ULV?
They are separate specifications from different automakers for related 10-speed transmissions. Some fluids are marketed for both; check each label against your manual.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].