AMSOIL Tranny Fluid Recommendation
02-03-2009, 12:02 AM
#1
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AMSOIL Tranny Fluid Recommendation
Mods, I know this is a little out of place, but I get many many PMs on this topic and I'm trying to be proactive with the group that goes through the most tranny fluid before I log off the forum for a few months.
A quick update on my recommendation for the Tremec manual transmissions before I go offline for a few months. Won't check this thread again for several months, so I apologize in advance if you have any questions.
I recommend (for Tremec manuals):
AMSOIL Torque-Drive Synthetic Transmission Fluid (product code ATD1G, commonly referred to as AMSOIL ATD)
Background:
The issue has been that AMSOIL has two automatic transmission fluids that are labeled to be suitable for Dexron III applications by AMSOIL, the AMSOIL ATF and the AMSOIL Torque Drive (ATD).
I have been using the AMSOIL ATF, a Dexron III fluid, in my 02 Z06 and 06 CTS-V for years with good results. Last year, AMSOIL reformulated this fluid and slightly lowered its hot cSt viscosity from about 7.2 to 6.8 so as to make it suitable for GM's new Dexron VI specification. A nominal Dexron III fluid has a new hot viscosity of about 7.3, but shears rapidly down to about 5.0-5.5. After 10k miles, my factory fill Dexron III in my CTS-V had sheared down to 5.0. I replaced it with AMSOIL ATF and ran it for 6k miles until I just swapped it out with the AMSOIL Torque Drive ATD. After 6k miles, the AMSOIL ATF's viscosity remained at 6.8 showing extremely good shear stability. I'll post the actual Blackstone Lab results when I return.
Given that Dexron III starts with a higher viscosity than the AMSOIL ATF, but the AMSOIL Torque Drive ATD hot viscosity of 7.4 essentially matches that of new Dexron III, I queried AMSOIL about why they recommended the ATF over the ATD for Dexron III applications. After analysis of the issue, AMSOIL revised their primary recommendation for Tremec manuals requiring Dexron III from the AMSOIL ATF to the AMSOIL Torque Drive ATD. The AMSOIL Online Product Application Guide now shows the ATD as the primary recommendation and the ATF as secondary. I agree with this based on the ATDs higher viscosity and the fact that it has no viscosity modifiers and thus is extremely shear stable. I feel these make it the better of two good choices for the Tremec manual tranny.
Both the AMSOIL ATF and AMSOIL Torque Drive ATD use a synthetic Group IV, PAO basestock fluid and are very similar to each other. The primary difference is that the ATD has a little higher viscosity (7.4 vs 6.8) and no viscosity modifiers. However, the ATF is an extremely shear stable fluid as borne out by my 6k miles of use with no viscosity loss. For those with the ATF in their trannies, I would not run and change it out. For future changes, I'd use the ATD. I will change the tranny fluid in my Z06 (which I raced with this past October), from the ATF to the ATD for my races this upcoming spring.
FYI, I changed my CTS-V to the ATD a few weeks ago and have been driving with it in cold winter weather. I noted no difference in shift feel with the new fluid.
Note: For automatics, I still recommend the AMSOIL ATF (product code ATFQT)
A quick update on my recommendation for the Tremec manual transmissions before I go offline for a few months. Won't check this thread again for several months, so I apologize in advance if you have any questions.
I recommend (for Tremec manuals):
AMSOIL Torque-Drive Synthetic Transmission Fluid (product code ATD1G, commonly referred to as AMSOIL ATD)
Background:
The issue has been that AMSOIL has two automatic transmission fluids that are labeled to be suitable for Dexron III applications by AMSOIL, the AMSOIL ATF and the AMSOIL Torque Drive (ATD).
I have been using the AMSOIL ATF, a Dexron III fluid, in my 02 Z06 and 06 CTS-V for years with good results. Last year, AMSOIL reformulated this fluid and slightly lowered its hot cSt viscosity from about 7.2 to 6.8 so as to make it suitable for GM's new Dexron VI specification. A nominal Dexron III fluid has a new hot viscosity of about 7.3, but shears rapidly down to about 5.0-5.5. After 10k miles, my factory fill Dexron III in my CTS-V had sheared down to 5.0. I replaced it with AMSOIL ATF and ran it for 6k miles until I just swapped it out with the AMSOIL Torque Drive ATD. After 6k miles, the AMSOIL ATF's viscosity remained at 6.8 showing extremely good shear stability. I'll post the actual Blackstone Lab results when I return.
Given that Dexron III starts with a higher viscosity than the AMSOIL ATF, but the AMSOIL Torque Drive ATD hot viscosity of 7.4 essentially matches that of new Dexron III, I queried AMSOIL about why they recommended the ATF over the ATD for Dexron III applications. After analysis of the issue, AMSOIL revised their primary recommendation for Tremec manuals requiring Dexron III from the AMSOIL ATF to the AMSOIL Torque Drive ATD. The AMSOIL Online Product Application Guide now shows the ATD as the primary recommendation and the ATF as secondary. I agree with this based on the ATDs higher viscosity and the fact that it has no viscosity modifiers and thus is extremely shear stable. I feel these make it the better of two good choices for the Tremec manual tranny.
Both the AMSOIL ATF and AMSOIL Torque Drive ATD use a synthetic Group IV, PAO basestock fluid and are very similar to each other. The primary difference is that the ATD has a little higher viscosity (7.4 vs 6.8) and no viscosity modifiers. However, the ATF is an extremely shear stable fluid as borne out by my 6k miles of use with no viscosity loss. For those with the ATF in their trannies, I would not run and change it out. For future changes, I'd use the ATD. I will change the tranny fluid in my Z06 (which I raced with this past October), from the ATF to the ATD for my races this upcoming spring.
FYI, I changed my CTS-V to the ATD a few weeks ago and have been driving with it in cold winter weather. I noted no difference in shift feel with the new fluid.
Note: For automatics, I still recommend the AMSOIL ATF (product code ATFQT)
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C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Ordering Information (Retail sales using reference #1206638 benefit the forum.)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
AMSOIL Catalog
02-03-2009, 01:46 AM
#2
Burning Brakes
Thanks for the update, Brad. 
I tried RedLine MTL in a BMW M3 (E36), and it was a great upgrade in shifter feel except in cold weather, when it made shifting noticeably stiff until it warmed up. It sounds like ATD might work better in that regard.
Since we're on the subject - do you know what the current Amsoil recommendations would be for C6 oil & rear-end fluids?
My '08 Z51 Vette is mixed-use for street, auto-x AND track events. The car is currently stock, and I drive ~5-6k miles per year including track time, so I don't think I qualify for the 25,000 mile fluid change plan ...
I tried RedLine MTL in a BMW M3 (E36), and it was a great upgrade in shifter feel except in cold weather, when it made shifting noticeably stiff until it warmed up. It sounds like ATD might work better in that regard.
Since we're on the subject - do you know what the current Amsoil recommendations would be for C6 oil & rear-end fluids?
My '08 Z51 Vette is mixed-use for street, auto-x AND track events. The car is currently stock, and I drive ~5-6k miles per year including track time, so I don't think I qualify for the 25,000 mile fluid change plan ...
Last edited by EvilBoffin; 02-03-2009 at 07:10 PM.
02-04-2009, 12:50 PM
#3
Burning Brakes
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St. Jude Donor '10-'11
Brad may be out of reach ...
you can readily research the products against the vehicle on the Amsoil site (Amsoil dot com).
Here's an extract (there you'll get hyperlinks to product descriptions, etc.)
2008 6.2L
LUBRICANTS & FLUIDS
Engine Oil
Grade 1......API*[1]
SAE 0W-30 Synthetic Signature Series Oil
SAE 5W-30 Synthetic Motor Oil
SAE 5W-30 XL Synthetic Motor Oil
All Temps......5W-30
Manual Transmission,.....GLS[2]
Torque-Drive™ Synthetic Automatic Transmission Fluid (ATD)
Synthetic Automatic Transmission Fluid
Automatic Transmission,6L80.....AF6
Synthetic Automatic Transmission Fluid
Controlled Slip Differential, Rear .....GL-5*
All Temps......75W-90
Severe Gear 75W-90
you can readily research the products against the vehicle on the Amsoil site (Amsoil dot com).
Here's an extract (there you'll get hyperlinks to product descriptions, etc.)
2008 6.2L
LUBRICANTS & FLUIDS
Engine Oil
Grade 1......API*[1]
SAE 0W-30 Synthetic Signature Series Oil
SAE 5W-30 Synthetic Motor Oil
SAE 5W-30 XL Synthetic Motor Oil
All Temps......5W-30
Manual Transmission,.....GLS[2]
Torque-Drive™ Synthetic Automatic Transmission Fluid (ATD)
Synthetic Automatic Transmission Fluid
Automatic Transmission,6L80.....AF6
Synthetic Automatic Transmission Fluid
Controlled Slip Differential, Rear .....GL-5*
All Temps......75W-90
Severe Gear 75W-90
