Pennzoil Platinum 75W90 GL4/GL5 Gear Oil

[nobb]

I just noticed Pennzoil is now offering both GL4 and GL5 gear oil in the 75W90 viscosity grade which is perfect for my manual 4Runner. I've so far been running Redline products which is getting difficult and expensive to find here in Canada.

The differentials aren't picky, but does anyone see any issue with switching from Redline MT-90 to Pennzoil GL4 for the transmission? It's so much cheaper.

 

[JohnnyJohnson]

My local NAPA store carries Amsoil for $17. 34 US. I was having a problem finding the other in GL4.

 

[MolaKule]

Originally Posted by nobb
I just noticed Pennzoil is now offering both GL4 and GL5 gear oil in the 75W90 viscosity grade which is perfect for my manual 4Runner. I've so far been running Redline products which is getting difficult and expensive to find here in Canada.

The differentials aren't picky, but does anyone see any issue with switching from Redline MT-90 to Pennzoil GL4 for the transmission? It's so much cheaper.


Many differential lubes state GL-4 backwards compatibility but that does not mean they are suitable for MT's.

Differential lubes are usually higher in viscosity (thicker than MTF's) and do not have the required friction modifiers needed for manual transmissions.

The Pennzoil Synchromesh was the only MTF offered by Pennzoil and it is too thin for manuals that require 75W90 GL-4 MTFs.

I would recommend MTF specific GL-4 fluids in manual transmissions such as Redline's MT-90 and the Amsoil MTG as shown above.

 

[nobb]

Originally Posted by MolaKule


Many differential lubes state GL-4 backwards compatibility but that does not mean they are suitable for MT;s.

Differential lubes are usually higher in viscosity (thicker than MTF's) and do not have the required friction modifiers needed for manual transmissions.

The Pennzoil Synchromesh was the only MTF offered by Pennzoil and it is too thin for manuals that require 75W90 GL-4 MTFs.


It appears Pennzoil has both a 75W90 that's rated GL4 for transmissions and GL5 for differentials. But their product pages don't have much info.

GL4:
https://www.pennzoil.com/en_ca/prod...sLzIwMTZuZXdzbGV0dGVyLz9sb2NhbGU9ZW5fY2E

GL5:
https://www.pennzoil.com/en_ca/prod...sLzIwMTZuZXdzbGV0dGVyLz9sb2NhbGU9ZW5fY2E

 

[nobb]

Originally Posted by JohnnyJohnson
My local NAPA store carries Amsoil for $17. 34 US. I was having a problem finding the other in GL4.


Unfortunately the Napa here in Canada has a limited selection. Redline is $35+ per 1 L bottle, which is double the price of Pennzoil GL4.

 

[SteveG4]

Stick with a NAPA, Pennzoil or Mobil-1 product that specifically meets your specs.
And being you're in Canada -- where it actually gets cold on occasion -- stick with a fully synthetic product.

 

[nobb]

Originally Posted by SteveG4
Stick with a NAPA, Pennzoil or Mobil-1 product that specfically meets your specs.


The Pennzoil 75W90 GL4 does meet spec. I'm just wondering what advantage going with a premium oil like Redline MT90 would make.

 

[expat]

Originally Posted by nobb
Originally Posted by SteveG4
Stick with a NAPA, Pennzoil or Mobil-1 product that specfically meets your specs.


The Pennzoil 75W90 GL4 does meet spec. I'm just wondering what advantage going with a premium oil like Redline MT90 would make.



Are you saying that Pennzoil 75w-90 GL4 has friction modifiers suitable for syncromesh transmissions?

 

[nobb]

Originally Posted by expat

Are you saying that Pennzoil 75w-90 GL4 has friction modifiers suitable for syncromesh transmissions?


The product page doesn't have any info on this. Also the manufacturer spec says that both GL4 or GL5 is suitable in the transmission, but the general consensus is that GL4 is better. I don't think I've ever seen an owners manual ever making specific reference to friction modifiers.

 

[MolaKule]

As I stated before:

Quote
Many differential lubes state GL-4 backwards compatibility but that does not mean they are suitable for MT's.

Differential lubes are usually higher in viscosity (thicker than MTF's) and do not have the required friction modifiers needed for manual transmissions.

The Pennzoil Synchromesh was the only MTF offered by Pennzoil and it is too thin for manuals that require 75W90 GL-4 MTFs.

I would recommend MTF specific GL-4 fluids in manual transmissions such as Redline's MT-90 and the Amsoil MTG as shown above.




Originally Posted by nobb
I don't think I've ever seen an owners manual ever making specific reference to friction modifiers.



Of course not, because the transmission engineers who specify the MTF know that the finished lube contains the friction modifier(s) necessary for synchronized shifting.


Originally Posted by nobb
It appears Pennzoil has both a 75W90 that's rated GL4 for transmissions and GL5 for differentials. But their product pages don't have much info.

GL4:
https://www.pennzoil.com/en_ca/prod...sLzIwMTZuZXdzbGV0dGVyLz9sb2NhbGU9ZW5fY2E


This lube does appear to be a new entry by Pennzoil into the MT market for a 75W90 GL-4 MT fluid and may contain the needed friction modifiers for synchronized transmissions.

Originally Posted by nobb
GL5:
https://www.pennzoil.com/en_ca/prod...sLzIwMTZuZXdzbGV0dGVyLz9sb2NhbGU9ZW5fY2E


This lube is stated as an AXLE lube which means it is a thicker fluid for Hypoid differentials.


I see no real "Lubricant Properties" nor what suggested transmissions or differentials might be covered by either lubricant or what specifications they might meet.


Here is a list of current 75W90 MT fluids

NOTE: This list is only a "suggested" list of MTFs. It is not an endorsement of any one fluid, nor is it implied that any one fluid will cure problems in MTs that have design problems or those that have excessive wear.

Amsoil MTG
Redline MT-90
Castrol Syntrans Multivehicle 75W-90
Castrol Syntrans Transaxle 75w-90
Ford XT-75W90-QGT (Carries a GL-5 rating as well)
Ford MOTORCRAFT® Full Synthetic Manual Transmission Fluid XT-M5-QS
ACDelco 10-4059 GL-4 75W-90 Manual Transmission Fluid
ACDelco 89021806 For use in MA5 manual transmission for GMT 345, GMT 355 Trucks and GMX 020 Cobalt Pursuit and G5 Passenger only. Caution: Rated at GL-3 (ExxonMobil fluid).
RAVENOL TSG SAE 75W-90
LiquiMoly 75W-90 GL4