But I really wanna go with Royal Purple lol.
No store in Central Florida carries Redline and their company is based in California. Shipping is expensive for these fluids post 9/11.

So are the two fluids I showed you good for my applications?

No, but it's your car. I'm out. You've gotten plenty of good advice and you're going in a different direction out of laziness or cheapness. Z1 is in Georgia and carries Redline. Good luck.

Lol! Every single product has mixed reviews. You claim that there are many bad stories to Royal Purple, but Ive seen many good.
I dont know. Maybe I will order Redline from Georgia, but... What is the factory OEM specs for both oils? I thought it was 75W90 for trans AND diff...

Redline is what you want

/discussion

I'm not going off stories or reviews, dude. Bob is the oil guy is a forum, like this one, where fluid engineers debate these things. That is where you go for info, not online reviews. The factory specs are in your manual, but there is a very good reason we're all running MT-85.

So Redline MT-85 and 75W90 gear oil will eliminate my notchy, otherwise stiff shifting?

I have attached the recommended fluids per the FSM. They are not the same.

Chuck is pretty damn knowledgeable. I have done my research as well. You're getting some solid info here, but we can't force you to accept it as truth.

If you want to question why we all recommend Redline MT-85 over the 75W per the FSM, then maybe you can do the research yourself?

If the issue is fluid related, yes. If not you have to start looking at mechanical causes. But this is the most likely solution.

Not guaranteed, but it's a good start. Even if it doesn't, you are better off with it :twocents:

BTW, OP...

I responded to your post on the differential fluid DIY thread. You do not need an extra quart (2 is fine) for the diff fluid. However, the transmission fluid calls for 3 qt, and it is recommended that you get an extra. The fluid you're pumping into the transmission should come out the fill hole when full.

Just checked their website, I dont think Z1 sells Redline anymore. Looks like they opted for Motul...

Didn't look too hard I guess.

Red Line MT-85

Red Line 75W90 Diff Fluid (1qt)

lol are you just trying to find excuses not to use Redline now?

Red Line 75W90 Diff Fluid (1qt)

Red Line MT-85

I agree with Chuck and Blue, these guys know their s***! I've been using redline for a while, it's great.

OMG I used the search button "redline" and nothing popped up. I swear!