Yeah, question is in the subject... Does anyone know what the difference is?

 

Do not use GL-5 in a 4Gen Maxima.

Copied from the Pennzoil site http://www.pennzoil.com/carcare/faq/default.htm#4

2. What happens if API GL-5 gear oil is used in an API GL-4 gear oil application?

API GL-4 and API GL-5 products typically use the same extreme pressure (EP) additive system, with the API GL-5 having about twice the concentration of a API GL-4. In service, these additives become active under extreme load and temperature when the protective oil film can be squeezed away. EP additives work by forming wear-resistant compounds with the metal of the gear tooth surface. As the gears mesh, these compounds shield the gear teeth from direct metal-to-metal contact that would cause wear and damage to the gears. If too little of the active additive is present, proper protection would be compromised. Too much of this additive could cause excessive chemical corrosion of the gear surface. If an API GL-5 gear oil is used in a application where API GL-4 gear oil is called for, chemical corrosion of "yellow metal" components may occur, such as bronze synchronizers, brass bushings, etc. This may lead to shifting difficulties or shortened equipment life.

 

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I don't understand this post. Do you disagree with the information on the Pennzoil Web site?

 

I understand not using GL-5 in our cars, but what about how synthetics are rated. All the bottles I've seen (Mobil 1 and Amsoil) say good for GL1-5. If we use these, and I know many of us do, will these oils eat the tranny?? In other words, what makes a synthetic that says it's good for GL4 and GL5 safe to use in Maxima's?? Just looking for input.

 

Thanks for the advice, I went and hunted around for a GL-4 rated MT oil but I couldn't find any!! I literally went to 3 different auto supply stores... one sales rep told me that the GL-5 was a new spec that I was supposed to use and when I told them about the stuff I read on Pennzoil's website they stared at me like I was crazy... in any case I also visited the Nissan dealership near my house and they told me they use 80W90 GL-5 MT oil... again I recited my rant about what I read on Pennzoil and got some laughs... They say its safe, but I trust what you say Daniel, I'm gonna order some Redline MT90 this week and get the right stuff, I actually do feel a difference in shifting anyways i'm going to drive around in it with the GL-5 for a couple more days before I switch it out to the Redline.

 

In NO way was I disrespecting you Daniel B. in that one thread... I was just going "...$hit..." because I put in GL-5... I appreciate your help, the advice you give is like mana from heaven.. hahaha.

-norton