Oil choice

Hi Im using Millers CRX 75w90 transmission oil in my gear box and diffs, and im just about to buy some more, that a good choice?

Also how much does the gearbox transfer and diff hold will 6lt cover it?

Im also doing an engine oil change which im using Millers CFS 10w40, same question is it a good choice?

Nothing wrong with Miller's I used to use Miller's 10w60, in my new engine I'm gonna be using Fuchs Titan pro S 10w/50, which seems to be a popular choice atm.

10 40 is fine for normal road use and a bit of a spirited drive, 10 50 is better if your a bit of an animal on the road and the odd track day,  and 10 60 if you're going to be doing track days.
as for the brand I dint think it matters too much as long as it's a good quality fully synthetic. Everyone has there personal choice. I used to use castrol then Mobil 1

Im using the millers cfs 10w/40.

Have Fuchs titan 10w/50 if it gets proper scorchio this summer.

I use fuchs titan 10w 50  for engine and gulf racing 75w90 in gearbox

Millers CRX is my favourite for R box
Good oil, more sensible price & no issues with the syncros

Gearbox 4.2L
Transfer 1.5L
Rear Diff 1L

Millers CFS 10w50 is good all round ester blend oil for engine, once again fractionally better price than some others in the same class.

Thanks chaps i am planning on doin a few track days so maybe ill get a higher rated one.