I am looking for a synthetic Dexron II/III ATF with the best cold weather properties for a PS system. Amsoil and Mobil 1 both have a Brookfield viscosity at -40 of around 10000 cP. Are there any better options available or is this as good as it gets?
Dexron III for Cold Weather
- Thread starter Oldswagon
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I have always liked Mobil1 Dexronlll/Mercon full synthetic ATF,
Valvoline MaxLife full synthetic ATFand
Castrol TransMax full synthetic Dexlll/Merc or even Multi-Vehicle ATF.
I’ve used all with great success in Dex/Merc required transmissions.
Valvoline MaxLife full synthetic ATFand
Castrol TransMax full synthetic Dexlll/Merc or even Multi-Vehicle ATF.
I’ve used all with great success in Dex/Merc required transmissions.
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I’d use the Amsoil or the Mobil 1 ATF.
Red Line Power Steering Fluid
https://www.redlineoil.com/power-steering-fluid
https://www.redlineoil.com/power-steering-fluid
It is all more or less the same. Lots of equipment specs dexron as hydraulic fluid in the cold.
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- Dec 20, 2022
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I'd throw High Performance Lubricants (HPL) Cold Climate Blue into the running.
Mobil Delvac 1 ATF, or any TES-295 fluid. Many of the 295 fluids used to carry a Dex III license.
https://www.mobil.com/en/lubricants/for-businesses/heavy-duty-lubricants/products/mobil-delvac-1-atf
https://www.mobil.com/en/lubricants/for-businesses/heavy-duty-lubricants/products/mobil-delvac-1-atf
Red Line D4 has one of the lowest PPs I’ve seen, -76F.
I use mag1 Fully Synthetic MultiVehicle ATF. Mag1 website says suitable for use Dexron III G/H, Dexron II, Dexron. Pour point of -60F and viscosity of 10,300 cP at -40F.
Why not just use an LV fluid like Dexron VI if the cold weather performance is not by regular Dex/Merc?
Back when Dex VI was introduced, Dex III from Petro Canada flowed better at -40. Of course that was 20 years ago can't comment on current. Allison TES-295 and successor spec are PAO based Dex III replacements and do even better. For the military start up test at -60F we ran Emgard 0W20 which was a MIL-L-2104 spec engine oil that stuff would stink up the whole test cell not sure what it was that caused that.
4wd
$50 site donor 2026
What I just bought
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Thanks for all the replies. HPL's stuff looks decent but is cost prohibitive to those of us in Canada. I wish there were Canadian dealers. My PS system requires DexI II/III so not sure I should try a LV ATF.
I am thinking I might go with Redline, their D4 has significantly better cold weather specs than most others. It's even better than many LV AYFs. Here are the specs.
I am thinking I might go with Redline, their D4 has significantly better cold weather specs than most others. It's even better than many LV AYFs. Here are the specs.
Typical Properties
| SAE Viscosity Grade (Motor Oil) | 0W20 |
| SAE Viscosity Grade (Gear Oil) | 70W80 |
| Vis @ 100°C, cSt | 7.5 |
| Vis @ 40°C, cSt | 35.4 |
| Viscosity Index | 188 |
| Pour Point, °C | -60 |
| Pour Point, °F | -76 |
| Brookfield Viscosity @ -40°C, Poise | 52 |
@Oldswagon where in Canada are you?
This is the stuff I run in all my PS systems and most transmissions. I pay 11 to 12 bucks a litre, tax in. Made in Regina, full PAO and makes quite a difference in the extreme cold.
This is the stuff I run in all my PS systems and most transmissions. I pay 11 to 12 bucks a litre, tax in. Made in Regina, full PAO and makes quite a difference in the extreme cold.
It's not exotic PS system, but an LV might be too thin in hot weather. And most don't offer any performance in the cold that is as good as the Redline D4.
I am in northern Ontario. What is the stuff you run? You didn't mention the product.
@Oldswagon sorry, I did not link the photo for some reason. Its my usual go to, Co-op ATF SL. Made by Federated Co-op. Its widely available through the prairies and even into BC but I am not sure out east.
@4wd it’s great to see that this is still available. On my last ATF change, I switched from the OEM Dexron VI to this Mobil 1 synthetic ATF and it greatly reduced the incidence of shuttering that I would sometimes get in hot weather for the LaSabre’s 4T65E transmission. It’s getting to be about time to do another drain and fill, but I’m having a difficult time finding this product and do not and will not use Dexron VI regardless of what GM says about backwards compatibility. And I say this because the LeSabre’s original owner , although he religiously changed the ATF on time, he had last used Dexron VI for his last ATF change and I noticed a distinct difference after changing to this Mobil 1 Dex III product. I’m not quite able to tell from the picture you posted, but can you or anyone here tell me where this product can still be purchased? Please and thank you 