Thanks for the useful and interesting replies.
Our engineers looked for a suitable moose droll based grease, but the pour point of the base fluid is way to high for the application...
As others mentioned, the grease is apparently no big deal. Nonetheless, I went with
Timken synth industrial grease which is NLGI grade 1.5 with a -50F to 356F operating temp range and a very high viscosity index. So it may make a small difference on short cold start trips. I chose this specific one mainly because I can get it for cheap.