HPL ATF Green - GM 8L45/8L90

Joined
Jan 23, 2013
Messages
195
Location
MA
I've got a 2021 GMC Canyon with the 8L45 and its first transmission fluid change isn't too far away. I was planning on Mobil 1's LV ATF HP which GM uses for the transmission TSB's as the Dexron HP wasn't up the task.

I've recently become a fan of @High Performance Lubricants motor oils and found out that they make ATF Green which is compatible and "Meets or Exceeds" Dexron HP. They also make a "CC" version for use in Cold Climates.

Anyone try this stuff yet? I'm curious as to how it compares to the ACDelco Dexron HP or M1's LV ATF.

Thanks!
 
Anyone try this stuff yet? I'm curious as to how it compares to the ACDelco Dexron HP or M1's LV ATF.
It's the same additive package as Mobil 1 LV ATF HP, however, HPL Green ATF is blended with additional detergents in the form of a proprietary co-base for added cleanliness. The regular version is blended with Group III and the CC version is blended with PAO. The AC Delco is blended by Petro Canada, and, let's just say, it is the least preferred option. Just skip it. Use either HPL or Mobil 1 blue label Dexron HP. I actually run the M1 Dexron HP in a Hyundai 6-speed and a ZF 8HP70 with great results.
 
@Rod Knock Thanks! I've already got a case of the M1 LV HP stuff so I'll probably go through that first...then on the HPL. Is their Green ATF actually green in color or is it just the color of the label on the bottle? Not that I care much either way but was just curious.
 
How many miles do you have on it? I'm at 20k and thinking of changing it around 30k (recommended interval is 48k). As most know this unit can be plagued with shudder issues. Most of the 21/22's don't have it, but it can still happen even in current model years (although rare). This transmission is very smooth shifting but concerns me long term after reading the internal memos between GM and attorneys.
 
I’ll tell you next week, Buster. My PPE deep 10R80 pan delivers tomorrow, and I have 8 gallons of Green CC waiting to swap it out. Got a military discount on the pan, salty salty filter from the Ford dealer, and the ATF from Dave. All in, about $550 to upgrade and service an $8k transmission. Will also reset the shift logic at that time so it learns the new fluid.
 
I used the Mobil 1 HP LV since I already had it. Changed it at 25k and replaced the filter. I think it was a good decision as the old fluid definitely had that used ATF smell to it. I only drained and filled which is about 40% of the fluid in this trans.

I'm at 35k and plan to do 1 or two more drain and fills for the fun of it. At 60k when the warranty is up I'm going to do a 100% flush with the HPL Green CC and put a fresh filter in there. I intend to install an in-line full flow transmission filter at the same time while I'm at it to keep the fluid as clean as I can.
 
I did a drain and fill on my 2012 Frontier with HPL ATF Green CC (as a test) and while it is only about 40% of the total mix, the shifting is definite but smooth.

I also replaced the Transfer Case fluid with HPL ATF Blue CC and the 4-wheel engagements-dis-engagements are much improved.
Mola, so if the fluid “meets or exceeds” a given spec, is it the friction modifiers or …? That causes the change in shift feel? Is it components that have sheared? Just trying to understand how “similar-spec” fluids can have massively different performance characteristics. Lastly, does the more definite engagement suffer any wear penalties or is it simply how the fluid interacts between the transfer surfaces?
 
Meets or exceeds means it has to have comparable anti-wear, viscosity stability, anti-oxidant stability, and metal inhibition.

The total Mu(v) (dynamic friction) coefficient is a result of the friction modification chemistry and the clutch face material and determines engagement/disengagement characteristics.

A quality VII component insures the viscosity remains stable since a poor VII would allow too much shearing.

Clutch engagement/disengagement programming is designed to keep clutch face wear to a minimum.

I am not sure what you mean by "... “similar-spec” fluids can have massively different performance characteristics."
 
I am not sure what you mean by "... “similar-spec” fluids can have massively different performance characteristics."
Well, I assume that you chose the Green and Blue for each application in your truck because that’s what was most similar to the spec, correct? And yet you noted some differences.

We’ve seen some similar things when going from say Mercon LV to Amsoil ATL in Ford 6F35s… “similar-spec” because Mercon LV has requirements, yet Motorcraft and Amsoil get there in different ways, but still meet “the spec”. Yet even when some have owned a vehicle since new, the different (Amsoil in the Ford instance or HPL in yours), the owners feel there is a difference in performance.

Just trying to understand if there is a lot of room to adjust the Mu or other characteristics in a given spec; or is it simply fresh fluid that results in the perceived improvement; or is it merely confirmation bias if the two fluids meet the same spec? Thanks.
 
I think every multi-speed vehicle trans made today is using similar forms of adaptive logic, so your slip times should converge to the same number of milliseconds whatever the fluid. Unless you have some major outlier condition that prevents this from happening.
 
Hopefully this a fair thread to inquire as it is HPL ATF related.

I have a 2008 Honda Pilot with 115K miles that originally specifies Honda ATF-Z1 transmission fluid. I have tried AMSOil ATF Red Cap and ATL Blue Cap (light formula). I think it ran and shifted better (smoother) on the AMSOil ATF Red Cap as this was a closer match to the original spec Honda Z1 formula.

However, I am not too impressed with either formula’s shift quality smoothness in the Pilot. I have heard it speculated that AMSOil may have changed its ATF\ATL formula in 2022 that may have improved the DI package.

I am currently running AMSOil purchased in Jan 2021 but before I change out the current AMSOil ATL Blue Cap back to ATF Red Cap, I wanted to try the “High Performance Lubricants” ATF.

Does anyone have experience with HPL ATF in Honda transmissions with originally specified Z1 fluid or other Honda transmissions as they can be sensitive to the type of ATF used? If so, how is the shift quality smoothness and what HPL ATF formula were you using?

Any comments welcome.

Respectfully
 
Last edited:
I have a 2008 Honda Pilot with 115K miles that originally specifies Honda ATF-Z1 transmission fluid. I have tried AMSOil ATF Red Cap and ATL Blue Cap (light formula). I think it ran and shifted better (smoother) on the AMSOil ATF Red Cap as this was a closer match to the original spec Honda Z1 formula.

However, I am not too impressed with either formula’s shift quality smoothness in the Pilot. I have heard it speculated that AMSOil may have changed its ATF\ATL formula in 2022 that may have improved the DI package.
Matches my experience with Amsoil (and every other multi-vehicle ATF) in a Honda application - the shift quality is simply inferior to the OE fluid.

For the record, I have not used the HPL product in a Honda application.
 
Matches my experience with Amsoil (and every other multi-vehicle ATF) in a Honda application - the shift quality is simply inferior to the OE fluid.

For the record, I have not used the HPL product in a Honda application.
Thanks for the confirmation. Good to know it is not an over sensitivity to shift smoothness on my part. :)
 
Back
Top