Will switching to an aftermarket transmission oil void the factory warranty?

 

Amzoil recommends their SVG (GL-5) severe gear lube first over AGL (GL-5) synthetic gear lube for passenger or racing applications. The only difference is in the weight. SVG is 75W90 and AGL is 80W90. I don't feel that the lower viscosity of the SVG is worthy of concern because of its superior lubricating qualities. Amzoil even lists SVG as a replacement for competitors 80W90 gear lubes.

I would be more concerned about using GL-4 in the manual trans and GL-5 in the differential. The GL-5 rating requires anti-slip additives for the clutch in the Z's differential. The manual trans has a "dry" clutch thus requiring only a GL-4 rated lube in the gear box.

Synthetic Manual Transmission and Transaxle Gear Lube (75W-90) API GL-4 for the MT.

SEVERE GEAR 75W-90 Synthetic EP Lubricant for the DIFF.

I could be wrong but that's how I see it.

 

damfly- you are right on. Amsoil's new product "MTG" is now available for the MT:
http://www.amsoil.com/StoreFront/mtg.aspx

There are several options for the rear diff- I agree with your chioce.