On Mon, 1 Oct 2001 09:24:11 -0700 (PDT), you wrote: >My '88 90 non Q calls for 75W90 "GL4" synth gear oil. >I found Mobil 1 "GL5". Can the GL5 ge used for the >car or is there something bad waiting to happen if it is? GL-4 and GL-5 are two different specifications and cannot be interchanged.. -- Regards, ES